Radial Shaft

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I Vuori - One of the best experts on this subject based on the ideXlab platform.

  • effects of unilateral strength training and detraining on bone mineral mass and estimated mechanical characteristics of the upper limb bones in young women
    Journal of Bone and Mineral Research, 2009
    Co-Authors: M Ari D Heinonen, Harri Sievanen, Pekka Kannus, Pekka Oja, I Vuori
    Abstract:

    The aims of this study were to examine the effects of 12 months unilateral high-resistance strength training and 8-month detraining on bone mineral content (BMC), density (BMD) and estimated mechanical characteristics of upper limb bones, and also to estimate consequent loading induced strains on forearm bone Shafts. Thirteen female physiotherapy students (mean 23.8 +/- 5.0 yrs, 166 +/- 7 cm, 64.4 +/- 7 cm, 64.4 +/- 13.3 kg) trained their left upper limbs with dumbbells on average 2.8 times per week for 12 months, followed by eight months detraining. Nineteen students served as controls (mean 25.7 +/- 5.2 yrs, 165 +/- 4 cm, 62.1 +/- 7.0 kg). BMC, BMD, and bone width and estimated cortical wall thickness (CWT) were measured at five different sites in both upper extremities (proximal humerus, humeral Shaft, Radial Shaft, ulnar Shaft, and distal forearm) using dual energy x-ray absorptiometry (DXA) scanner. In addition, cross-sectional moment of inertia (CSMI) was estimated from DXA data. The maximal isometric strength of the upper extremities was measured with an arm flexion-extension dynamometer. The training increased significantly the flexion strength by 14% (p = 0.001). During the detraining period, all measured strength values in the training group decreased in both limbs with respect to values after training. Despite the clear effect on muscular strength, no significant intergroup differences were observed in BMC, BMD, bone width, CWT, or CSMI values at any measured site after the training or detraining period. The estimated loading-induced strains remained within customary loading, and the change in strain level was only 15%. In conclusion, this study indicated that using high-resistance strength training may not provide an effective osteogenic stimulus for bone formation and geometric changes in upper limb bones of young, healthy, adult women. The interaction of bones and muscles may play an important and relatively unrecognized role in the development of bone strength, suggesting that the entire biomechanical environment should be carefully considered when evaluating the osteogenic efficiency of physical loading.

  • exercise induced bone gain is due to enlargement in bone size without a change in volumetric bone density a peripheral quantitative computed tomography study of the upper arms of male tennis players
    Bone, 2000
    Co-Authors: H Haapasalo, Harri Sievanen, Pekka Kannus, Saija A Kontulainen, M Jarvinen, I Vuori
    Abstract:

    Bilateral bone characteristics of the humerus (proximal, Shaft, and distal sites) and radius (Shaft and distal sites) in 12 former Finnish national-level male tennis players (mean age 30 years) and their 12 age-, height-, and weight-matched controls were measured with peripheral quantitative computed tomography (pQCT). The pQCT variables analyzed were bone mineral content (BMC), total cross-sectional area of bone (Tot.Ar), cross-sectional area of the marrow cavity (M.Cav.Ar), cortical bone (Co.Ar) and trabecular bone (Tr.Ar), volumetric density of cortical (Co.Dn) and trabecular (Tr. Dn) bone, cortical wall thickness (Co.Wi.Th), bone strength index (BSI), and principal moments of inertia (I(min) and I(max)). In the players, significant side-to-side differences, in favor of the dominant (playing) arm, were found in BMC (ranging 14%-27%), Tot.Ar (16%-21%), Co.Ar (12%-32%), BSI (23%-37%), I(min) (33%-61%), and I(max) (27%-67%) at all measured bone sites, and in Co.Wi.Th. (5%-25%) at the humeral and Radial Shafts, and distal humerus. The side-to-side M.Cav.Ar difference was significant at the proximal humerus (19%) and Radial Shaft (29%). Concerning the players' Co.Dn and Tr.Dn, the only significant side-to-side difference was found in the Co.Dn of the distal humerus, with the playing arm showing a slightly smaller Co.Dn than the nonplaying arm (-2%). In controls, significant dominant-to-nondominant side differences were also found, but with the majority of the differences being rather small, and significantly lower than those of the players. In conclusion, despite the large side-to-side differences in BMC, the volumetric bone density (Co.Dn, Tr.Dn) was almost identical in the dominant and nondominant arms of the players and controls. Thus, the players' high playing-arm BMC was due to increases in the Tot.Ar, M.Cav.Ar, Co.Ar, and CW.Th. In other words, the playing arm's extra bone mineral, and thus increased bone strength, was mainly due to increased bone size and not due to a change in volumetric bone density. These upper arm results may not be generalized to the entire skeleton, but the finding may give new insight into conventional dual-energy X-ray absorptiometry (DXA)-based bone density measurements when interpreting the effects of exercise on bone.

  • exercise induced bone gain is due to enlargement in bone size without a change in volumetric bone density a peripheral quantitative computed tomography study of the upper arms of male tennis players
    Bone, 2000
    Co-Authors: H Haapasalo, Harri Sievanen, Pekka Kannus, Saija A Kontulainen, M Jarvinen, I Vuori
    Abstract:

    Bilateral bone characteristics of the humerus (proximal, Shaft, and distal sites) and radius (Shaft and distal sites) in 12 former Finnish national-level male tennis players (mean age 30 years) and their 12 age-, height-, and weight-matched controls were measured with peripheral quantitative computed tomography (pQCT). The pQCT variables analyzed were bone mineral content (BMC), total cross-sectional area of bone (Tot.Ar), cross-sectional area of the marrow cavity (M.Cav.Ar), cortical bone (Co.Ar) and trabecular bone (Tr.Ar), volumetric density of cortical (Co.Dn) and trabecular (Tr.Dn) bone, cortical wall thickness (Co.Wi.Th), bone strength index (BSI), and principal moments of inertia (Imin and Imax). In the players, significant side-to-side differences, in favor of the dominant (playing) arm, were found in BMC (ranging 14%‐27%), Tot.Ar (16%‐21%), Co.Ar (12%‐32%), BSI (23%‐37%), Imin (33%‐ 61%), and Imax (27%‐ 67%) at all measured bone sites, and in Co.Wi.Th. (5%‐25%) at the humeral and Radial Shafts, and distal humerus. The side-to-side M.Cav.Ar difference was significant at the proximal humerus (19%) and Radial Shaft (29%). Concerning the players’ Co.Dn and Tr.Dn, the only significant side-toside difference was found in the Co.Dn of the distal humerus, with the playing arm showing a slightly smaller Co.Dn than the nonplaying arm (22%). In controls, significant dominant-tonondominant side differences were also found, but with the majority of the differences being rather small, and significantly lower than those of the players. In conclusion, despite the large side-to-side differences in BMC, the volumetric bone density (Co.Dn, Tr.Dn) was almost identical in the dominant and nondominant arms of the players and controls. Thus, the players’ high playing-arm BMC was due to increases in the Tot.Ar, M.Cav.Ar, Co.Ar, and CW.Th. In other words, the playing arm’s extra bone mineral, and thus increased bone strength, was mainly due to increased bone size and not due to a change in volumetric bone density. These upper arm results may not be generalized to the entire skeleton, but the finding may give new insight into conventional dual-energy X-ray absorptiometry (DXA)-based bone density measurements when interpreting the effects of exercise on bone. (Bone 27:351‐357; 2000) © 2000 by Elsevier Science Inc. All rights reserved.

  • effect of starting age of physical activity on bone mass in the dominant arm of tennis and squash players
    Annals of Internal Medicine, 1995
    Co-Authors: Pekka Kannus, Harri Sievanen, Ari Heinonen, H Haapasalo, Marja Sankelo, M Pasanen, I Vuori
    Abstract:

    OBJECTIVE: To determine in female tennis and squash players the effect of biological age (that is, the starting age of playing relative to the age at menarche) at which tennis or squash playing was started on the difference in bone mineral content between the playing and non-playing arms. DESIGN: Cross-sectional study. SETTING: Finnish tennis and squash federations. PARTICIPANTS: 105 female Finnish national-level players and 50 healthy female controls. MAIN OUTCOME MEASURES: Differences in bone mineral content in playing and nonplaying (dominant to nondominant) arms (proximal humerus, humeral Shaft, Radial Shaft, and distal radius) were compared in the players and controls and among six groups of players. Players were divided into groups according to the biological age (years before or after menarche) at which their playing careers began: more than 5 years before; 3 to 5 years before; 2 to 0 years before; 1 to 5 years after; 6 to 15 years after; and more than 15 years after. RESULTS: Compared with controls (whose mean +/- SD differences in bone mineral content were 4.6% +/- 4.6%, 3.2% +/- 2.3%, 3.2% +/- 3.8%, and 3.9% +/- 4.3% at the previously noted anatomical sites), the players had a significantly (P < 0.001) larger side-to-side difference in every measured site (15.5% +/- 8.4%, 16.2% +/- 9.8%, 8.5% +/- 6.6, and 12.5% +/- 7.1%). Among players, the group differences in bone mineral content were significant (P < 0.001 to P = 0.005), with the group means clearly decreasing with increasing starting biological age of playing. The difference was two to four times greater in the players who had started their playing careers before or at menarche (lowest mean difference in bone mineral content, 10.5% +/- 7.2%; highest difference, 23.5% +/- 7.2%) than in those who started more than 15 years after menarche (lowest difference, 2.4% +/- 4.8%; highest difference, 9.6% +/- 4.9%). Adjustment for potential confounding factors (age and height) did not change these trends. CONCLUSIONS: Bones of the playing extremity clearly benefit from active tennis and squash training, which increases their mineral mass. The benefit of playing is about two times greater if females start playing at or before menarche rather than after it. The minimal level and minimum number of years of activity necessary to produce these results, the extent to which this benefit is sustained after cessation of intensive training, and the degree to which these results can be extended to other forms of physical activity and other bone sites should be studied further.

Pasko Rakic - One of the best experts on this subject based on the ideXlab platform.

  • elusive Radial glial cells historical and evolutionary perspective
    Glia, 2003
    Co-Authors: Pasko Rakic
    Abstract:

    Since the discovery of Radial glial cells in the human fetal forebrain, this specialized cellular population has been identified in most regions of the vertebrate brain during restricted developmental periods. However, their size, longevity, and significance for guiding migrating neurons have increased with the evolutionary expansion of the mammalian neocortex, reaching a peak in the gyrencephalic human forebrain. The phenotypic distinction of Radial glial cells from the more specialized neuronal progenitors in the proliferative zones and from the migrating neurons in the intermediate zone of the primate fetal forebrain, based initially on morphological criteria, has been supported by their ultrastructural, molecular, and physiological characteristics. In addition, modern in vivo and in vitro approaches revealed that these specialized embryonic cells can also generate neuronal cell lines, which either immediately, or after several divisions, migrate along Radial Shaft processes of the mother cells that span the expanding and convoluted cerebral wall. The multiple functions of Radial glial cells and their species-specific adaptations indicate a pivotal role in evolution, development, and pathology of the cerebral neocortex. GLIA 43:19–32, 2003. © 2003 Wiley-Liss, Inc.

  • elusive Radial glial cells historical and evolutionary perspective
    Glia, 2003
    Co-Authors: Pasko Rakic
    Abstract:

    Since the discovery of Radial glial cells in the human fetal forebrain, this specialized cellular population has been identified in most regions of the vertebrate brain during restricted developmental periods. However, their size, longevity, and significance for guiding migrating neurons have increased with the evolutionary expansion of the mammalian neocortex, reaching a peak in the gyrencephalic human forebrain. The phenotypic distinction of Radial glial cells from the more specialized neuronal progenitors in the proliferative zones and from the migrating neurons in the intermediate zone of the primate fetal forebrain, based initially on morphological criteria, has been supported by their ultrastructural, molecular, and physiological characteristics. In addition, modern in vivo and in vitro approaches revealed that these specialized embryonic cells can also generate neuronal cell lines, which either immediately, or after several divisions, migrate along Radial Shaft processes of the mother cells that span the expanding and convoluted cerebral wall. The multiple functions of Radial glial cells and their species-specific adaptations indicate a pivotal role in evolution, development, and pathology of the cerebral neocortex.

Pekka Kannus - One of the best experts on this subject based on the ideXlab platform.

  • effects of unilateral strength training and detraining on bone mineral mass and estimated mechanical characteristics of the upper limb bones in young women
    Journal of Bone and Mineral Research, 2009
    Co-Authors: M Ari D Heinonen, Harri Sievanen, Pekka Kannus, Pekka Oja, I Vuori
    Abstract:

    The aims of this study were to examine the effects of 12 months unilateral high-resistance strength training and 8-month detraining on bone mineral content (BMC), density (BMD) and estimated mechanical characteristics of upper limb bones, and also to estimate consequent loading induced strains on forearm bone Shafts. Thirteen female physiotherapy students (mean 23.8 +/- 5.0 yrs, 166 +/- 7 cm, 64.4 +/- 7 cm, 64.4 +/- 13.3 kg) trained their left upper limbs with dumbbells on average 2.8 times per week for 12 months, followed by eight months detraining. Nineteen students served as controls (mean 25.7 +/- 5.2 yrs, 165 +/- 4 cm, 62.1 +/- 7.0 kg). BMC, BMD, and bone width and estimated cortical wall thickness (CWT) were measured at five different sites in both upper extremities (proximal humerus, humeral Shaft, Radial Shaft, ulnar Shaft, and distal forearm) using dual energy x-ray absorptiometry (DXA) scanner. In addition, cross-sectional moment of inertia (CSMI) was estimated from DXA data. The maximal isometric strength of the upper extremities was measured with an arm flexion-extension dynamometer. The training increased significantly the flexion strength by 14% (p = 0.001). During the detraining period, all measured strength values in the training group decreased in both limbs with respect to values after training. Despite the clear effect on muscular strength, no significant intergroup differences were observed in BMC, BMD, bone width, CWT, or CSMI values at any measured site after the training or detraining period. The estimated loading-induced strains remained within customary loading, and the change in strain level was only 15%. In conclusion, this study indicated that using high-resistance strength training may not provide an effective osteogenic stimulus for bone formation and geometric changes in upper limb bones of young, healthy, adult women. The interaction of bones and muscles may play an important and relatively unrecognized role in the development of bone strength, suggesting that the entire biomechanical environment should be carefully considered when evaluating the osteogenic efficiency of physical loading.

  • a rotator cuff rupture produces permanent osteoporosis in the affected extremity but not in those with whom shoulder function has returned to normal
    Journal of Bone and Mineral Research, 2009
    Co-Authors: Pekka Kannus, Harri Sievanen, Jari Leppala, M U K Lehto, Ari Heinonen, Markku Jarvinen
    Abstract:

    Areal bone mineral density (BMD) and clinical status of 34 men treated surgically 9 years earlier for a rotator cuff rupture of the dominant side shoulder were determined. The BMD was measured at the lumbar spine (L2-L4) and the proximal humerus, humeral Shaft, Radial Shaft, ulnar Shaft, distal forearm, and hand of both extremities using a dual-energy X-ray absorptiometric (DXA) scanner. Thirty-four age-, height-, weight-, and profession-matched normal men (controls) were also measured. The patients' mean side-to-side BMD difference (dominant minus nondominant/nondominant x 100%) was significantly lower in the proximal humerus (patients -3.5% vs. controls +2.4%, p = 0.0002), humeral Shaft (-2.6% vs. +1.6%, p = 0.0005), Radial Shaft (-0.4% vs. +1.9%, p = 0.0311), distal forearm (-0.2% vs. +2.4%, p = 0.0158), and hand (+2.3% vs. +4.0%, p = 0.0047). In the ulnar Shaft, this difference was almost the same in the patients (-0.2%) and controls (+0.2%) (NS). Also, the lumbar spine BMD did not differ significantly between these groups (mean +/- SD = 1.098 +/- 0.148 g/cm2 in patients vs. 1.066 +/- 0.156 g/cm2 in controls). In patients, the relative BMDs of the injured extremity did not significantly associate with the size of the rupture; time delay between the injury and the surgery; type of surgery and postoperative treatment; postoperative immobilization time; follow-up time; patient's age, muscle strength or pain assessment; and subjective assessment of shoulder function. However, they strongly associated with the objective assessment of the shoulder function: the better the observed function of the shoulder, the less bone loss caused by the injury.(ABSTRACT TRUNCATED AT 250 WORDS)

  • exercise induced bone gain is due to enlargement in bone size without a change in volumetric bone density a peripheral quantitative computed tomography study of the upper arms of male tennis players
    Bone, 2000
    Co-Authors: H Haapasalo, Harri Sievanen, Pekka Kannus, Saija A Kontulainen, M Jarvinen, I Vuori
    Abstract:

    Bilateral bone characteristics of the humerus (proximal, Shaft, and distal sites) and radius (Shaft and distal sites) in 12 former Finnish national-level male tennis players (mean age 30 years) and their 12 age-, height-, and weight-matched controls were measured with peripheral quantitative computed tomography (pQCT). The pQCT variables analyzed were bone mineral content (BMC), total cross-sectional area of bone (Tot.Ar), cross-sectional area of the marrow cavity (M.Cav.Ar), cortical bone (Co.Ar) and trabecular bone (Tr.Ar), volumetric density of cortical (Co.Dn) and trabecular (Tr. Dn) bone, cortical wall thickness (Co.Wi.Th), bone strength index (BSI), and principal moments of inertia (I(min) and I(max)). In the players, significant side-to-side differences, in favor of the dominant (playing) arm, were found in BMC (ranging 14%-27%), Tot.Ar (16%-21%), Co.Ar (12%-32%), BSI (23%-37%), I(min) (33%-61%), and I(max) (27%-67%) at all measured bone sites, and in Co.Wi.Th. (5%-25%) at the humeral and Radial Shafts, and distal humerus. The side-to-side M.Cav.Ar difference was significant at the proximal humerus (19%) and Radial Shaft (29%). Concerning the players' Co.Dn and Tr.Dn, the only significant side-to-side difference was found in the Co.Dn of the distal humerus, with the playing arm showing a slightly smaller Co.Dn than the nonplaying arm (-2%). In controls, significant dominant-to-nondominant side differences were also found, but with the majority of the differences being rather small, and significantly lower than those of the players. In conclusion, despite the large side-to-side differences in BMC, the volumetric bone density (Co.Dn, Tr.Dn) was almost identical in the dominant and nondominant arms of the players and controls. Thus, the players' high playing-arm BMC was due to increases in the Tot.Ar, M.Cav.Ar, Co.Ar, and CW.Th. In other words, the playing arm's extra bone mineral, and thus increased bone strength, was mainly due to increased bone size and not due to a change in volumetric bone density. These upper arm results may not be generalized to the entire skeleton, but the finding may give new insight into conventional dual-energy X-ray absorptiometry (DXA)-based bone density measurements when interpreting the effects of exercise on bone.

  • exercise induced bone gain is due to enlargement in bone size without a change in volumetric bone density a peripheral quantitative computed tomography study of the upper arms of male tennis players
    Bone, 2000
    Co-Authors: H Haapasalo, Harri Sievanen, Pekka Kannus, Saija A Kontulainen, M Jarvinen, I Vuori
    Abstract:

    Bilateral bone characteristics of the humerus (proximal, Shaft, and distal sites) and radius (Shaft and distal sites) in 12 former Finnish national-level male tennis players (mean age 30 years) and their 12 age-, height-, and weight-matched controls were measured with peripheral quantitative computed tomography (pQCT). The pQCT variables analyzed were bone mineral content (BMC), total cross-sectional area of bone (Tot.Ar), cross-sectional area of the marrow cavity (M.Cav.Ar), cortical bone (Co.Ar) and trabecular bone (Tr.Ar), volumetric density of cortical (Co.Dn) and trabecular (Tr.Dn) bone, cortical wall thickness (Co.Wi.Th), bone strength index (BSI), and principal moments of inertia (Imin and Imax). In the players, significant side-to-side differences, in favor of the dominant (playing) arm, were found in BMC (ranging 14%‐27%), Tot.Ar (16%‐21%), Co.Ar (12%‐32%), BSI (23%‐37%), Imin (33%‐ 61%), and Imax (27%‐ 67%) at all measured bone sites, and in Co.Wi.Th. (5%‐25%) at the humeral and Radial Shafts, and distal humerus. The side-to-side M.Cav.Ar difference was significant at the proximal humerus (19%) and Radial Shaft (29%). Concerning the players’ Co.Dn and Tr.Dn, the only significant side-toside difference was found in the Co.Dn of the distal humerus, with the playing arm showing a slightly smaller Co.Dn than the nonplaying arm (22%). In controls, significant dominant-tonondominant side differences were also found, but with the majority of the differences being rather small, and significantly lower than those of the players. In conclusion, despite the large side-to-side differences in BMC, the volumetric bone density (Co.Dn, Tr.Dn) was almost identical in the dominant and nondominant arms of the players and controls. Thus, the players’ high playing-arm BMC was due to increases in the Tot.Ar, M.Cav.Ar, Co.Ar, and CW.Th. In other words, the playing arm’s extra bone mineral, and thus increased bone strength, was mainly due to increased bone size and not due to a change in volumetric bone density. These upper arm results may not be generalized to the entire skeleton, but the finding may give new insight into conventional dual-energy X-ray absorptiometry (DXA)-based bone density measurements when interpreting the effects of exercise on bone. (Bone 27:351‐357; 2000) © 2000 by Elsevier Science Inc. All rights reserved.

  • effect of starting age of physical activity on bone mass in the dominant arm of tennis and squash players
    Annals of Internal Medicine, 1995
    Co-Authors: Pekka Kannus, Harri Sievanen, Ari Heinonen, H Haapasalo, Marja Sankelo, M Pasanen, I Vuori
    Abstract:

    OBJECTIVE: To determine in female tennis and squash players the effect of biological age (that is, the starting age of playing relative to the age at menarche) at which tennis or squash playing was started on the difference in bone mineral content between the playing and non-playing arms. DESIGN: Cross-sectional study. SETTING: Finnish tennis and squash federations. PARTICIPANTS: 105 female Finnish national-level players and 50 healthy female controls. MAIN OUTCOME MEASURES: Differences in bone mineral content in playing and nonplaying (dominant to nondominant) arms (proximal humerus, humeral Shaft, Radial Shaft, and distal radius) were compared in the players and controls and among six groups of players. Players were divided into groups according to the biological age (years before or after menarche) at which their playing careers began: more than 5 years before; 3 to 5 years before; 2 to 0 years before; 1 to 5 years after; 6 to 15 years after; and more than 15 years after. RESULTS: Compared with controls (whose mean +/- SD differences in bone mineral content were 4.6% +/- 4.6%, 3.2% +/- 2.3%, 3.2% +/- 3.8%, and 3.9% +/- 4.3% at the previously noted anatomical sites), the players had a significantly (P < 0.001) larger side-to-side difference in every measured site (15.5% +/- 8.4%, 16.2% +/- 9.8%, 8.5% +/- 6.6, and 12.5% +/- 7.1%). Among players, the group differences in bone mineral content were significant (P < 0.001 to P = 0.005), with the group means clearly decreasing with increasing starting biological age of playing. The difference was two to four times greater in the players who had started their playing careers before or at menarche (lowest mean difference in bone mineral content, 10.5% +/- 7.2%; highest difference, 23.5% +/- 7.2%) than in those who started more than 15 years after menarche (lowest difference, 2.4% +/- 4.8%; highest difference, 9.6% +/- 4.9%). Adjustment for potential confounding factors (age and height) did not change these trends. CONCLUSIONS: Bones of the playing extremity clearly benefit from active tennis and squash training, which increases their mineral mass. The benefit of playing is about two times greater if females start playing at or before menarche rather than after it. The minimal level and minimum number of years of activity necessary to produce these results, the extent to which this benefit is sustained after cessation of intensive training, and the degree to which these results can be extended to other forms of physical activity and other bone sites should be studied further.

Harri Sievanen - One of the best experts on this subject based on the ideXlab platform.

  • effects of unilateral strength training and detraining on bone mineral mass and estimated mechanical characteristics of the upper limb bones in young women
    Journal of Bone and Mineral Research, 2009
    Co-Authors: M Ari D Heinonen, Harri Sievanen, Pekka Kannus, Pekka Oja, I Vuori
    Abstract:

    The aims of this study were to examine the effects of 12 months unilateral high-resistance strength training and 8-month detraining on bone mineral content (BMC), density (BMD) and estimated mechanical characteristics of upper limb bones, and also to estimate consequent loading induced strains on forearm bone Shafts. Thirteen female physiotherapy students (mean 23.8 +/- 5.0 yrs, 166 +/- 7 cm, 64.4 +/- 7 cm, 64.4 +/- 13.3 kg) trained their left upper limbs with dumbbells on average 2.8 times per week for 12 months, followed by eight months detraining. Nineteen students served as controls (mean 25.7 +/- 5.2 yrs, 165 +/- 4 cm, 62.1 +/- 7.0 kg). BMC, BMD, and bone width and estimated cortical wall thickness (CWT) were measured at five different sites in both upper extremities (proximal humerus, humeral Shaft, Radial Shaft, ulnar Shaft, and distal forearm) using dual energy x-ray absorptiometry (DXA) scanner. In addition, cross-sectional moment of inertia (CSMI) was estimated from DXA data. The maximal isometric strength of the upper extremities was measured with an arm flexion-extension dynamometer. The training increased significantly the flexion strength by 14% (p = 0.001). During the detraining period, all measured strength values in the training group decreased in both limbs with respect to values after training. Despite the clear effect on muscular strength, no significant intergroup differences were observed in BMC, BMD, bone width, CWT, or CSMI values at any measured site after the training or detraining period. The estimated loading-induced strains remained within customary loading, and the change in strain level was only 15%. In conclusion, this study indicated that using high-resistance strength training may not provide an effective osteogenic stimulus for bone formation and geometric changes in upper limb bones of young, healthy, adult women. The interaction of bones and muscles may play an important and relatively unrecognized role in the development of bone strength, suggesting that the entire biomechanical environment should be carefully considered when evaluating the osteogenic efficiency of physical loading.

  • a rotator cuff rupture produces permanent osteoporosis in the affected extremity but not in those with whom shoulder function has returned to normal
    Journal of Bone and Mineral Research, 2009
    Co-Authors: Pekka Kannus, Harri Sievanen, Jari Leppala, M U K Lehto, Ari Heinonen, Markku Jarvinen
    Abstract:

    Areal bone mineral density (BMD) and clinical status of 34 men treated surgically 9 years earlier for a rotator cuff rupture of the dominant side shoulder were determined. The BMD was measured at the lumbar spine (L2-L4) and the proximal humerus, humeral Shaft, Radial Shaft, ulnar Shaft, distal forearm, and hand of both extremities using a dual-energy X-ray absorptiometric (DXA) scanner. Thirty-four age-, height-, weight-, and profession-matched normal men (controls) were also measured. The patients' mean side-to-side BMD difference (dominant minus nondominant/nondominant x 100%) was significantly lower in the proximal humerus (patients -3.5% vs. controls +2.4%, p = 0.0002), humeral Shaft (-2.6% vs. +1.6%, p = 0.0005), Radial Shaft (-0.4% vs. +1.9%, p = 0.0311), distal forearm (-0.2% vs. +2.4%, p = 0.0158), and hand (+2.3% vs. +4.0%, p = 0.0047). In the ulnar Shaft, this difference was almost the same in the patients (-0.2%) and controls (+0.2%) (NS). Also, the lumbar spine BMD did not differ significantly between these groups (mean +/- SD = 1.098 +/- 0.148 g/cm2 in patients vs. 1.066 +/- 0.156 g/cm2 in controls). In patients, the relative BMDs of the injured extremity did not significantly associate with the size of the rupture; time delay between the injury and the surgery; type of surgery and postoperative treatment; postoperative immobilization time; follow-up time; patient's age, muscle strength or pain assessment; and subjective assessment of shoulder function. However, they strongly associated with the objective assessment of the shoulder function: the better the observed function of the shoulder, the less bone loss caused by the injury.(ABSTRACT TRUNCATED AT 250 WORDS)

  • exercise induced bone gain is due to enlargement in bone size without a change in volumetric bone density a peripheral quantitative computed tomography study of the upper arms of male tennis players
    Bone, 2000
    Co-Authors: H Haapasalo, Harri Sievanen, Pekka Kannus, Saija A Kontulainen, M Jarvinen, I Vuori
    Abstract:

    Bilateral bone characteristics of the humerus (proximal, Shaft, and distal sites) and radius (Shaft and distal sites) in 12 former Finnish national-level male tennis players (mean age 30 years) and their 12 age-, height-, and weight-matched controls were measured with peripheral quantitative computed tomography (pQCT). The pQCT variables analyzed were bone mineral content (BMC), total cross-sectional area of bone (Tot.Ar), cross-sectional area of the marrow cavity (M.Cav.Ar), cortical bone (Co.Ar) and trabecular bone (Tr.Ar), volumetric density of cortical (Co.Dn) and trabecular (Tr. Dn) bone, cortical wall thickness (Co.Wi.Th), bone strength index (BSI), and principal moments of inertia (I(min) and I(max)). In the players, significant side-to-side differences, in favor of the dominant (playing) arm, were found in BMC (ranging 14%-27%), Tot.Ar (16%-21%), Co.Ar (12%-32%), BSI (23%-37%), I(min) (33%-61%), and I(max) (27%-67%) at all measured bone sites, and in Co.Wi.Th. (5%-25%) at the humeral and Radial Shafts, and distal humerus. The side-to-side M.Cav.Ar difference was significant at the proximal humerus (19%) and Radial Shaft (29%). Concerning the players' Co.Dn and Tr.Dn, the only significant side-to-side difference was found in the Co.Dn of the distal humerus, with the playing arm showing a slightly smaller Co.Dn than the nonplaying arm (-2%). In controls, significant dominant-to-nondominant side differences were also found, but with the majority of the differences being rather small, and significantly lower than those of the players. In conclusion, despite the large side-to-side differences in BMC, the volumetric bone density (Co.Dn, Tr.Dn) was almost identical in the dominant and nondominant arms of the players and controls. Thus, the players' high playing-arm BMC was due to increases in the Tot.Ar, M.Cav.Ar, Co.Ar, and CW.Th. In other words, the playing arm's extra bone mineral, and thus increased bone strength, was mainly due to increased bone size and not due to a change in volumetric bone density. These upper arm results may not be generalized to the entire skeleton, but the finding may give new insight into conventional dual-energy X-ray absorptiometry (DXA)-based bone density measurements when interpreting the effects of exercise on bone.

  • exercise induced bone gain is due to enlargement in bone size without a change in volumetric bone density a peripheral quantitative computed tomography study of the upper arms of male tennis players
    Bone, 2000
    Co-Authors: H Haapasalo, Harri Sievanen, Pekka Kannus, Saija A Kontulainen, M Jarvinen, I Vuori
    Abstract:

    Bilateral bone characteristics of the humerus (proximal, Shaft, and distal sites) and radius (Shaft and distal sites) in 12 former Finnish national-level male tennis players (mean age 30 years) and their 12 age-, height-, and weight-matched controls were measured with peripheral quantitative computed tomography (pQCT). The pQCT variables analyzed were bone mineral content (BMC), total cross-sectional area of bone (Tot.Ar), cross-sectional area of the marrow cavity (M.Cav.Ar), cortical bone (Co.Ar) and trabecular bone (Tr.Ar), volumetric density of cortical (Co.Dn) and trabecular (Tr.Dn) bone, cortical wall thickness (Co.Wi.Th), bone strength index (BSI), and principal moments of inertia (Imin and Imax). In the players, significant side-to-side differences, in favor of the dominant (playing) arm, were found in BMC (ranging 14%‐27%), Tot.Ar (16%‐21%), Co.Ar (12%‐32%), BSI (23%‐37%), Imin (33%‐ 61%), and Imax (27%‐ 67%) at all measured bone sites, and in Co.Wi.Th. (5%‐25%) at the humeral and Radial Shafts, and distal humerus. The side-to-side M.Cav.Ar difference was significant at the proximal humerus (19%) and Radial Shaft (29%). Concerning the players’ Co.Dn and Tr.Dn, the only significant side-toside difference was found in the Co.Dn of the distal humerus, with the playing arm showing a slightly smaller Co.Dn than the nonplaying arm (22%). In controls, significant dominant-tonondominant side differences were also found, but with the majority of the differences being rather small, and significantly lower than those of the players. In conclusion, despite the large side-to-side differences in BMC, the volumetric bone density (Co.Dn, Tr.Dn) was almost identical in the dominant and nondominant arms of the players and controls. Thus, the players’ high playing-arm BMC was due to increases in the Tot.Ar, M.Cav.Ar, Co.Ar, and CW.Th. In other words, the playing arm’s extra bone mineral, and thus increased bone strength, was mainly due to increased bone size and not due to a change in volumetric bone density. These upper arm results may not be generalized to the entire skeleton, but the finding may give new insight into conventional dual-energy X-ray absorptiometry (DXA)-based bone density measurements when interpreting the effects of exercise on bone. (Bone 27:351‐357; 2000) © 2000 by Elsevier Science Inc. All rights reserved.

  • effect of starting age of physical activity on bone mass in the dominant arm of tennis and squash players
    Annals of Internal Medicine, 1995
    Co-Authors: Pekka Kannus, Harri Sievanen, Ari Heinonen, H Haapasalo, Marja Sankelo, M Pasanen, I Vuori
    Abstract:

    OBJECTIVE: To determine in female tennis and squash players the effect of biological age (that is, the starting age of playing relative to the age at menarche) at which tennis or squash playing was started on the difference in bone mineral content between the playing and non-playing arms. DESIGN: Cross-sectional study. SETTING: Finnish tennis and squash federations. PARTICIPANTS: 105 female Finnish national-level players and 50 healthy female controls. MAIN OUTCOME MEASURES: Differences in bone mineral content in playing and nonplaying (dominant to nondominant) arms (proximal humerus, humeral Shaft, Radial Shaft, and distal radius) were compared in the players and controls and among six groups of players. Players were divided into groups according to the biological age (years before or after menarche) at which their playing careers began: more than 5 years before; 3 to 5 years before; 2 to 0 years before; 1 to 5 years after; 6 to 15 years after; and more than 15 years after. RESULTS: Compared with controls (whose mean +/- SD differences in bone mineral content were 4.6% +/- 4.6%, 3.2% +/- 2.3%, 3.2% +/- 3.8%, and 3.9% +/- 4.3% at the previously noted anatomical sites), the players had a significantly (P < 0.001) larger side-to-side difference in every measured site (15.5% +/- 8.4%, 16.2% +/- 9.8%, 8.5% +/- 6.6, and 12.5% +/- 7.1%). Among players, the group differences in bone mineral content were significant (P < 0.001 to P = 0.005), with the group means clearly decreasing with increasing starting biological age of playing. The difference was two to four times greater in the players who had started their playing careers before or at menarche (lowest mean difference in bone mineral content, 10.5% +/- 7.2%; highest difference, 23.5% +/- 7.2%) than in those who started more than 15 years after menarche (lowest difference, 2.4% +/- 4.8%; highest difference, 9.6% +/- 4.9%). Adjustment for potential confounding factors (age and height) did not change these trends. CONCLUSIONS: Bones of the playing extremity clearly benefit from active tennis and squash training, which increases their mineral mass. The benefit of playing is about two times greater if females start playing at or before menarche rather than after it. The minimal level and minimum number of years of activity necessary to produce these results, the extent to which this benefit is sustained after cessation of intensive training, and the degree to which these results can be extended to other forms of physical activity and other bone sites should be studied further.

Douglas P Kiel - One of the best experts on this subject based on the ideXlab platform.

  • risk factors for longitudinal bone loss in elderly men and women the framingham osteoporosis study
    Journal of Bone and Mineral Research, 2010
    Co-Authors: Adrienne L Cupples, Marian T Hannan, Peter W F Wilson, Katherine L Tucker, David T Felson, Bess Dawsonhughes, Douglas P Kiel
    Abstract:

    Few studies have evaluated risk factors for bone loss in elderly women and men. Thus, we examined risk factors for 4-year longitudinal change in bone mineral density (BMD) at the hip, radius, and spine in elders. Eight hundred elderly women and men from the population-based Framingham Osteoporosis Study had BMD assessed in 1988-1989 and again in 1992-1993. BMD was measured at femoral neck, trochanter, Ward's area, Radial Shaft, ultradistal radius, and lumbar spine using Lunar densitometers. We examined the relation of the following factors at baseline to percent BMD loss: age, weight, change in weight, height, smoking, caffeine, alcohol use, physical activity, serum 25-OH vitamin D, calcium intake, and current estrogen replacement in women. Multivariate regression analyses were conducted with simultaneous adjustment for all variables. Mean age at baseline was 74 years ± 4.5 years (range, 67-90 years). Average 4-year BMD loss for women (range, 3.4-4.8%) was greater than the loss for men (range, 0.2-3.6%) at all sites; however, BMD fell with age in both elderly women and elderly men. For women, lower baseline weight, weight loss in interim, and greater alcohol use were associated with BMD loss. Women who gained weight during the interim gained BMD or had little change in BMD. For women, current estrogen users had less bone loss than nonusers; at the femoral neck, nonusers lost up to 2.7% more BMD. For men, lower baseline weight and weight loss also were associated with BMD loss. Men who smoked cigarettes at baseline lost more BMD at the trochanter site. Surprisingly, bone loss was not affected by caffeine, physical activity, serum 25-OH vitamin D, or calcium intake. Risk factors consistently associated with bone loss in elders include female sex, thinness, and weight loss, while weight gain appears to protect against bone loss for both men and women. This population-based study suggests that current estrogen use may help to maintain bone in women, whereas current smoking was associated with bone loss in men. Even in the elderly years, potentially modifiable risk factors, such as weight, estrogen use, and cigarette smoking are important components of bone health.

  • inverse association of carotenoid intakes with 4 y change in bone mineral density in elderly men and women the framingham osteoporosis study
    The American Journal of Clinical Nutrition, 2009
    Co-Authors: Shivani Sahni, Adrienne L Cupples, Marian T Hannan, Douglas P Kiel, Jeffrey B Blumberg, Katherine L Tucker
    Abstract:

    Background: In vitro and in vivo studies suggest that carotenoids may inhibit bone resorption and stimulate proliferation and differentiation of osteoblasts. Few studies have examined the association between carotenoid intake (other than β-carotene) and bone mineral density (BMD). Objective: We evaluated associations between total and individual carotenoid intake (α-carotene, β-carotene, β-cryptoxanthin, lycopene, and lutein+zeaxanthin) with BMD at the hip, spine, and Radial Shaft and the 4-y change in BMD. Design: Both cross-sectional and longitudinal analyses were conducted in 334 men and 540 women (mean ± SD age: 75 ± 5 y) in the Framingham Osteoporosis Study. Energy-adjusted carotenoid intakes were estimated from the Willett food-frequency questionnaire. Mean BMD and mean 4-y BMD changes were estimated, for men and women separately, by quartile of carotenoid intake with adjustment for age, BMI, height, physical activity index, smoking (never compared with ever smokers), multivitamin use, season of BMD measurement (for cross-sectional analyses on BMD only), estrogen use (in women), and intakes of total energy, calcium, vitamin D, caffeine, and alcohol. Results: Few cross-sectional associations were observed with carotenoid intake. Associations between lycopene intake and 4-y change in lumbar spine BMD were significant for women (P for trend = 0.03), as were intakes of total carotenoids, β-carotene, lycopene and lutein+zeaxanthin with 4-y change in trochanter BMD in men (P for trend = 0.0005, 0.02, 0.009, and 0.008, respectively). Conclusions: Carotenoids showed protective associations against 4-y loss in trochanter BMD in men and in lumbar spine in women. No significant associations were observed at other bone sites. Although not consistent across all BMD sites examined, these results support a protective role of carotenoids for BMD in older men and women.

  • long term effects of serum cholesterol on bone mineral density in women and men the framingham osteoporosis study
    Bone, 2004
    Co-Authors: Elizabeth J Samelson, Adrienne L Cupples, Marian T Hannan, Peter W F Wilson, Setareh A Williams, Viola Vaccarino, Yuqing Zhang, Douglas P Kiel
    Abstract:

    Laboratory studies have suggested a role for cholesterol in the pathogenesis of both osteoporosis and atherosclerosis. The purpose of this prospective study was to assess whether cholesterol levels, repeatedly measured over three decades in young and middle-aged adult women and men, predicted bone mineral density (BMD) at advanced age. Study participants included 712 women and 450 men enrolled in the Framingham Osteoporosis Study, aged 32-61 years at baseline (1953-55) who underwent bone densitometry 34 years later (1988-1989). BMD was measured at the proximal femur (neck, trochanter, and Ward's triangle) and lumbar spine using dual-photon absorptiometry and at the one-third Radial Shaft and ultradistal radius using single-photon absorptiometry. Sex-specific multivariable linear regression was used to model each BMD site as a function of total cholesterol level, adjusted for age, cigarette smoking, alcohol consumption, body mass index, systolic blood pressure, diabetes, and estrogen use (women). No significant association between total cholesterol and BMD was found in women for any of the bone sites considered. For example, adjusted mean BMD at the lumbar spine was similar in women from the lowest to highest quartile of total cholesterol, respectively, 1.07, 1.08, 1.06, 1.07 g/cm2; P for trend=0.98. Similarly, the findings in men largely showed no association between cholesterol and BMD, although there was an isolated finding of a statistically significant trend in decreasing mean Radial Shaft BMD with increasing total cholesterol, 0.73, 0.72, 0.72, 0.70 g/cm2, lowest to highest quartile, P for trend=0.02. Cholesterol levels in women and men from young adulthood to middle age years do not appear to have long-term clinical implications for osteoporosis later in life.

  • bone mineral density and dietary patterns in older adults the framingham osteoporosis study
    The American Journal of Clinical Nutrition, 2002
    Co-Authors: Katherine L Tucker, Adrienne L Cupples, Marian T Hannan, Peter W F Wilson, Honglei Chen, David T Felson, Douglas P Kiel
    Abstract:

    Background: Several nutrients are known to affect bone mineral density (BMD). However, these nutrients occur together in foods and dietary patterns, and the overall effects of dietary choices are not well understood. Objective: We evaluated associations between dietary patterns and BMD in older adults. Design: Of the original Framingham Heart Study subjects, 907 aged 69-93 y completed food-frequency questionnaires as part of an osteoporosis study. We defined dietary patterns by cluster analysis. BMD was measured at the proximal right femur (femoral neck, trochanter, Ward's area) with a dual-photon absorptiometer and at the 33% Radial Shaft with a single-photon absorptiometer. We regressed BMD measures onto the cluster variable, adjusting for potential confounders. Results: Six dietary patterns were identified, with relatively greater proportions of intake from meat, dairy, and bread; meat and sweet baked products; sweet baked products; alcohol; candy; and fruit, vegetables, and cereal. After adjustment for multiple comparisons, men in the last group had significantly (P = 0.05) greater BMD than did 2-4 other groups at the hip sites and the candy group at the radius. Men in the candy group had significantly (P < 0.05) lower BMD than did those in the fruit, vegetables, and cereal group for 3 of the 4 sites. Women in the candy group had significantly (P <0.01) lower BMD than did all but one other group at the radius. Conclusions: Dietary pattern is associated with BMD. High fruit and vegetable intake appears to be protective in men. High candy consumption was associated with low BMD in both men and women.

  • effect of dietary protein on bone loss in elderly men and women the framingham osteoporosis study
    Journal of Bone and Mineral Research, 2000
    Co-Authors: Adrienne L Cupples, Marian T Hannan, Katherine L Tucker, David T Felson, Bess Dawsonhughes, Douglas P Kiel
    Abstract:

    Few studies have evaluated protein intake and bone loss in elders. Excess protein may be associated with negative calcium balance, whereas low protein intake has been associated with fracture. We examined the relation between baseline dietary protein and subsequent 4-year change in bone mineral density (BMD) for 391 women and 224 men from the population-based Framingham Osteoporosis Study. BMD (g/cm2) was assessed in 1988-1989 and in 1992-1993 at the femur, spine, and radius. Usual dietary protein intake was determined using a semiquantitative food frequency questionnaire (FFQ) and expressed as percent of energy from protein intake. BMD loss over 4 years was regressed on percent protein intake, simultaneously adjusting for other baseline factors: age, weight, height, weight change, total energy intake, smoking, alcohol intake, caffeine, physical activity, calcium intake, and, for women, current estrogen use. Effects of animal protein on bone loss also were examined. Mean age at baseline (+/-SD) of 615 participants was 75 years (+/-4.4; range, 68-91 years). Mean protein intake was 68 g/day (+/-24.0; range, 14-175 g/day), and mean percent of energy from protein was 16% (+/-3.4; range, 7-30%). Proportional protein intakes were similar for men and women. Lower protein intake was significantly related to bone loss at femoral and spine sites (p < or = 0.04) with effects similar to 10 lb of weight. Persons in the lowest quartile of protein intake showed the greatest bone loss. Similar to the overall protein effect, lower percent animal protein also was significantly related to bone loss at femoral and spine BMD sites (all p < 0.01) but not the Radial Shaft (p = 0.23). Even after controlling for known confounders including weight loss, women and men with relatively lower protein intake had increased bone loss, suggesting that protein intake is important in maintaining bone or minimizing bone loss in elderly persons. Further, higher intake of animal protein does not appear to affect the skeleton adversely in this elderly population.

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