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William E Garrett - One of the best experts on this subject based on the ideXlab platform.
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the effect of hamstring flexibility on peak hamstring Muscle Strain in sprinting
Journal of Sport and Health Science, 2017Co-Authors: Xianglin Wan, William E Garrett, Hui LiuAbstract:Abstract Background The effect of hamstring flexibility on the peak hamstring Muscle Strains in sprinting, until now, remained unknown, which limited our understanding of risk factors of hamstring Muscle Strain injury (hamstring injury). As a continuation of our previous study, this study was aimed to examine the relationship between hamstring flexibility and peak hamstring Muscle Strains in sprinting. Methods Ten male and 10 female college students participated in this study. Hamstring flexibility, isokinetic strength data, three-dimensional (3D) kinematic data in a hamstring isokinetic test, and kinematic data in a sprinting test were collected for each participant. The optimal hamstring Muscle lengths and peak hamstring Muscle Strains in sprinting were determined for each participant. Results The Muscle Strain of each of the 3 biarticulated hamstring Muscles reached a peak during the late swing phase. Peak hamstring Muscle Strains were negatively correlated to hamstring flexibility (0.1179 ≤ R 2 ≤ 0.4519, p = 0.001) but not to hip and knee joint positions at the time of peak hamstring Muscle Strains. Peak hamstring Muscle Strains were not different for different genders. Peak Muscle Strains of biceps long head (0.071 ± 0.059) and semitendinosus (0.070 ± 0.055) were significantly greater than that of semimembranosus (0.064 ± 0.054). Conclusion A potential for hamstring injury exists during the late swing phase of sprinting. Peak hamstring Muscle Strains in sprinting are negatively correlated to hamstring flexibility across individuals. The magnitude of peak Muscle Strains is different among hamstring Muscles in sprinting, which may explain the different injury rate among hamstring Muscles.
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relationships among hamstring Muscle optimal length and hamstring flexibility and strength
Journal of Sport and Health Science, 2017Co-Authors: Xianglin Wan, William E Garrett, Hui LiuAbstract:Background Hamstring Muscle Strain injury (hamstring injury) due to excessive Muscle Strain is one of the most common injuries in sports. The relationships among hamstring Muscle optimal lengths and hamstring flexibility and strength were unknown, which limited our understanding of risk factors for hamstring injury. This study was aimed at examining the relationships among hamstring Muscle optimal length and flexibility and strength.
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hamstring Muscle kinematics and activation during overground sprinting
Journal of Biomechanics, 2008Co-Authors: Robin M Queen, Alicia N Abbey, Yu Liu, Claude T Moorman, William E GarrettAbstract:Abstract Hamstring Muscle Strain injury is one of the most commonly seen injuries in sports such as track and field, soccer, football, and rugby. The purpose of this study was to advance our understanding of the mechanisms of hamstring Muscle Strain injuries during over ground sprinting by investigating hamstring Muscle–tendon kinematics and Muscle activation. Three-dimensional videographic and electromyographic (EMG) data were collected for 20 male runners, soccer or lacrosse players performing overground sprinting at their maximum effort. Hamstring Muscle–tendon lengths, elongation velocities, and linear envelop EMG data were analyzed for a running gait cycle of the dominant leg. Hamstring Muscles exhibited eccentric contractions during the late stance phase as well as during the late swing phase of overground sprinting. The peak eccentric contraction speeds of the hamstring Muscles were significantly greater during the late swing phase than during the late stance phase ( p =0.001) while the hamstring Muscle–tendon lengths at the peak eccentric contraction speeds were significantly greater during the late stance phase than during the late swing phase ( p =0.001). No significant differences existed in the maximum hamstring Muscle–tendon lengths between the two eccentric contractions. The potential for hamstring Muscle Strain injury exists during the late stance phase as well as during the late swing phases of overground sprinting.
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Muscle Strain injury diagnosis and treatment
Journal of The American Academy of Orthopaedic Surgeons, 1999Co-Authors: Thomas J Noonan, William E GarrettAbstract:Muscle Strain is a very common injury. Muscles that are frequently involved cross two joints, act mainly in an eccentric fashion, and contain a high percentage of fast-twitch fibers. Muscle Strain usually causes acute pain and occurs during strenuous activity. In most cases, the diagnosis can be made on the basis of the history and physical examination. Magnetic resonance imaging is recommended only when radiologic evaluation is necessary for diagnosis. Initial treatment consists of rest, ice, compression, and nonsteroidal anti-inflammatory drug therapy. As pain and swelling subside, physical therapy should be initiated to restore flexibility and strength. Avoiding excessive fatigue and performing adequate warm-up before intense exercise may help to prevent Muscle Strain injury. The long-term outcome after Muscle Strain injury is usually excellent, and complications are few.
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the role of fatigue in susceptibility to acute Muscle Strain injury
American Journal of Sports Medicine, 1996Co-Authors: Scott D Mair, Anthony V Seaber, Richard R Glisson, William E GarrettAbstract:We investigated the role of fatigue in Muscle Strain injuries using the extensor digitorum longus Muscles of 48 rabbits. The Muscles of the rabbits were fatigued by 25% or 50% then stretched to failure and compared with the contralateral controls. Three rates of stretch were used. The force to Muscle failure was reduced in the fatigued leg in all groups (range, 93% to 97.4% compared with the controls). The change in Muscle length in the fatigue groups was not different from the controls. The amount of energy absorbed in the fatigued Muscle was 69.7% to 92% that of the energy absorbed in the control Muscle. The lowest energy absorption occurred in Muscles that were more fatigued. In eight additional rabbits, fatigued extensor digitorum longus Muscles were compared with submaximally stimulated Muscles with the equivalent contractile properties, and no difference was seen. Muscles subjected to Strains are frequently injured under high-intensity eccentric loading conditions. Under these conditions, Muscles absorb energy and provide control and regulation of limb movement. Our data showed that Muscles are injured at the same length, regardless of the effects of fatigue. However, fatigued Muscles are able to absorb less energy before reaching the degree of stretch that causes injuries.
Timothy F Tyler - One of the best experts on this subject based on the ideXlab platform.
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adductor Muscle Strains in sport
Sports Medicine, 2002Co-Authors: Stephen J Nicholas, Timothy F TylerAbstract:An in-season adductor Muscle Strain may be debilitating for the athlete. Furthermore, an adductor Strain that is treated improperly could become chronic and career threatening. Any one of the six Muscles of the adductor group could be involved. The degree of injury can range from a minor Strain (Grade I), where minimal playing time is lost, to a severe Strain (Grade III) in which there is complete loss of Muscle function.
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the association of hip strength and flexibility with the incidence of adductor Muscle Strains in professional ice hockey players
American Journal of Sports Medicine, 2001Co-Authors: Timothy F Tyler, Stephen J Nicholas, Richard J. Campbell, Malachy P. MchughAbstract:This prospective study was conducted to determine whether hip Muscle strength and flexibility play a role in the incidence of adductor and hip flexor Strains in National Hockey League ice hockey team players. Hip flexion, abduction, and adduction strength were measured in 81 players before two consecutive seasons. Thirty-four players were cut, traded, or sent to the minor league before the beginning of the season. Injury and individual exposure data were recorded for the remaining 47 players. Eight players experienced 11 adductor Muscle Strains, and there were 4 hip flexor Strains. Preseason hip adduction strength was 18% lower in the players who subsequently sustained an adductor Muscle Strain compared with that of uninjured players. Adduction strength was 95% of abduction strength in the uninjured players but only 78% of abduction strength in the injured players. Preseason hip adductor flexibility was not different between players who sustained adductor Muscle Strains and those who did not. These result...
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the association of hip strength and flexibility with the incidence of adductor Muscle Strains in professional ice hockey players
American Journal of Sports Medicine, 2001Co-Authors: Timothy F Tyler, Stephen J Nicholas, Richard J. Campbell, Malachy P. MchughAbstract:This prospective study was conducted to determine whether hip Muscle strength and flexibility play a role in the incidence of adductor and hip flexor Strains in National Hockey League ice hockey team players. Hip flexion, abduction, and adduction strength were measured in 81 players before two consecutive seasons. Thirty-four players were cut, traded, or sent to the minor league before the beginning of the season. Injury and individual exposure data were recorded for the remaining 47 players. Eight players experienced 11 adductor Muscle Strains, and there were 4 hip flexor Strains. Preseason hip adduction strength was 18% lower in the players who subsequently sustained an adductor Muscle Strain compared with that of uninjured players. Adduction strength was 95% of abduction strength in the uninjured players but only 78% of abduction strength in the injured players. Preseason hip adductor flexibility was not different between players who sustained adductor Muscle Strains and those who did not. These results indicate that preseason hip strength testing of professional ice hockey players can identify players at risk of developing adductor Muscle Strains. A player was 17 times more likely to sustain an adductor Muscle Strain if his adductor strength was less than 80% of his abductor strength.
Malachy P. Mchugh - One of the best experts on this subject based on the ideXlab platform.
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the association of hip strength and flexibility with the incidence of adductor Muscle Strains in professional ice hockey players
American Journal of Sports Medicine, 2001Co-Authors: Timothy F Tyler, Stephen J Nicholas, Richard J. Campbell, Malachy P. MchughAbstract:This prospective study was conducted to determine whether hip Muscle strength and flexibility play a role in the incidence of adductor and hip flexor Strains in National Hockey League ice hockey team players. Hip flexion, abduction, and adduction strength were measured in 81 players before two consecutive seasons. Thirty-four players were cut, traded, or sent to the minor league before the beginning of the season. Injury and individual exposure data were recorded for the remaining 47 players. Eight players experienced 11 adductor Muscle Strains, and there were 4 hip flexor Strains. Preseason hip adduction strength was 18% lower in the players who subsequently sustained an adductor Muscle Strain compared with that of uninjured players. Adduction strength was 95% of abduction strength in the uninjured players but only 78% of abduction strength in the injured players. Preseason hip adductor flexibility was not different between players who sustained adductor Muscle Strains and those who did not. These result...
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the association of hip strength and flexibility with the incidence of adductor Muscle Strains in professional ice hockey players
American Journal of Sports Medicine, 2001Co-Authors: Timothy F Tyler, Stephen J Nicholas, Richard J. Campbell, Malachy P. MchughAbstract:This prospective study was conducted to determine whether hip Muscle strength and flexibility play a role in the incidence of adductor and hip flexor Strains in National Hockey League ice hockey team players. Hip flexion, abduction, and adduction strength were measured in 81 players before two consecutive seasons. Thirty-four players were cut, traded, or sent to the minor league before the beginning of the season. Injury and individual exposure data were recorded for the remaining 47 players. Eight players experienced 11 adductor Muscle Strains, and there were 4 hip flexor Strains. Preseason hip adduction strength was 18% lower in the players who subsequently sustained an adductor Muscle Strain compared with that of uninjured players. Adduction strength was 95% of abduction strength in the uninjured players but only 78% of abduction strength in the injured players. Preseason hip adductor flexibility was not different between players who sustained adductor Muscle Strains and those who did not. These results indicate that preseason hip strength testing of professional ice hockey players can identify players at risk of developing adductor Muscle Strains. A player was 17 times more likely to sustain an adductor Muscle Strain if his adductor strength was less than 80% of his abductor strength.
Richard M Lovering - One of the best experts on this subject based on the ideXlab platform.
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use of autologous platelet rich plasma to treat Muscle Strain injuries
American Journal of Sports Medicine, 2009Co-Authors: Jason Hammond, Leigh Ann Curl, Joaquin M Muriel, Richard Y. Hinton, Richard M LoveringAbstract:BackgroundStandard nonoperative therapy for acute Muscle Strains usually involves short-term rest, ice, and nonsteroidal anti-inflammatory medications, but there is no clear consensus on how to accelerate recovery.Hypothesis Local delivery of platelet-rich plasma to injured Muscles hastens recovery of function.Study Design Controlled laboratory study.MethodsIn vivo, the tibialis anterior Muscles of anesthetized Sprague-Dawley rats were injured by a single (large Strain) lengthening contraction or multiple (small Strain) lengthening contractions, both of which resulted in a significant injury. The tibialis anterior either was injected with platelet-rich plasma, was injected with platelet-poor plasma as a sham treatment, or received no treatment.ResultsBoth injury protocols yielded a similar loss of force. The platelet-rich plasma only had a beneficial effect at 1 time point after the single contraction injury protocol. However, platelet-rich plasma had a beneficial effect at 2 time points after the multipl...
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use of autologous platelet rich plasma to treat Muscle Strain injuries
American Journal of Sports Medicine, 2009Co-Authors: Jason Hammond, Leigh Ann Curl, Joaquin M Muriel, Richard Y. Hinton, Richard M LoveringAbstract:Background Standard nonoperative therapy for acute Muscle Strains usually involves short-term rest, ice, and nonsteroidal anti-inflammatory medications, but there is no clear consensus on how to accelerate recovery. Hypothesis Local delivery of platelet-rich plasma to injured Muscles hastens recovery of function. Study design Controlled laboratory study. Methods In vivo, the tibialis anterior Muscles of anesthetized Sprague-Dawley rats were injured by a single (large Strain) lengthening contraction or multiple (small Strain) lengthening contractions, both of which resulted in a significant injury. The tibialis anterior either was injected with platelet-rich plasma, was injected with platelet-poor plasma as a sham treatment, or received no treatment. Results Both injury protocols yielded a similar loss of force. The platelet-rich plasma only had a beneficial effect at 1 time point after the single contraction injury protocol. However, platelet-rich plasma had a beneficial effect at 2 time points after the multiple contraction injury protocol and resulted in a faster recovery time to full contractile function. The sham injections had no effect compared with no treatment. Conclusion Local delivery of platelet-rich plasma can shorten recovery time after a Muscle Strain injury in a small-animal model. Recovery of Muscle from the high-repetition protocol has already been shown to require myogenesis, whereas recovery from a single Strain does not. This difference in mechanism of recovery may explain why platelet-rich plasma was more effective in the high-repetition protocol, because platelet-rich plasma is rich in growth factors that can stimulate myogenesis. Clinical relevance Because autologous blood products are safe, platelet-rich plasma may be a useful product in clinical treatment of Muscle injuries.
Geoffrey M Verrall - One of the best experts on this subject based on the ideXlab platform.
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assessment of player performance following return to sport after hamstring Muscle Strain injury
Journal of Science and Medicine in Sport, 2006Co-Authors: Geoffrey M Verrall, Y Kalairajah, John P Slavotinek, A J SprigginsAbstract:Summary Objective: To determine if there is any decrease in playing performance of athletes following return to sport after recovery from hamstring Muscle Strain injury. Design: Prospective cohort study. Participants: One professional Australian football team over two playing seasons. Methods: For every game, the team coach rated player performance proportional to time spent on the ground playing (an integer score out of a maximum of 10). Player performance ratings were compared pre- and post-hamstring Muscle Strain injury to assess player performance upon return to sport. Results: Thirteen athletes had hamstring injuries and the required player ratings were available. The mean player performance rating for the entire playing season in which the player was injured was 6.9. The mean player performance rating for the two games prior to injury was 6.8 as opposed to 5.4 for the two games after return to sport. Athletes had a significantly lower player performance rating immediately upon return to sport when compared to ratings for the entire season (p < 0.001) and when compared to ratings from the two games prior to injury (p < 0.001). Conclusions: Following return to sport from hamstring injury, player performance as assessed by the team coach is reduced. This suggests that some athletes may return
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assessment of physical examination and magnetic resonance imaging findings of hamstring injury as predictors for recurrent injury
Journal of Orthopaedic & Sports Physical Therapy, 2006Co-Authors: Geoffrey M Verrall, John P Slavotinek, Peter G Barnes, G T Fon, Adrian EstermanAbstract:Study Design Prospective cohort study. Objective To examine clinical and magnetic resonance imaging (MRI) features of hamstring Muscle injury to determine if any are predictive for recurrent injury. Background Hamstring Muscle Strain injury and subsequent recurrent injury are common. Little information exists on factors that may increase the risk for recurrent injury. Methods and Measures The subjects were athletes from 3 professional Australian Rules football teams (n = 162). Anthropometric measurements, clinical signs, convalescent interval, and MRI assessment and measurement were undertaken and recorded in athletes with hamstring Muscle Strain injury. Athletes were followed for the presence, or absence, of recurrent injury to the same-side posterior thigh over the same and subsequent playing seasons. Results Thirty athletes met criteria for hamstring injury. Twelve (40%) of 30 athletes had recurrent injury within the same season, with an additional 7 athletes having recurrent injury in the subsequent s...
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the effect of sports specific training on reducing the incidence of hamstring injuries in professional australian rules football players
British Journal of Sports Medicine, 2005Co-Authors: Geoffrey M Verrall, John P Slavotinek, Peter G BarnesAbstract:Objectives: To assess in a single team of Australian Rules football players the effect of a specific intervention program on the incidence and consequence of hamstring Muscle Strain injuries. Method: A prospective study was performed with a single team being followed for four playing seasons for hamstring injury. Magnetic resonance imaging was used to confirm the diagnosis of hamstring Muscle injury. After two playing seasons an intervention program was implemented with the number of athletes with hamstring injury, competition days missed, and incidence of hamstring match injuries per 1000 h of playing time being compared pre- and post-intervention. The intervention program involved stretching whilst fatigued, sport specific training drills, and an emphasis on increasing the amount of high intensity anaerobic interval training. Results: In the seasons prior to the intervention, nine and 11 athletes sustained hamstring injury compared to two and four following intervention. Competition days missed reduced from 31 and 38 to 5 and 16 following intervention and match incidence decreased from 4.7 to 1.3 per 1000 h of playing time. A beneficial effect was demonstrated with a smaller number of players having hamstring injuries (p = 0.05), a lower number of competition games missed being recorded (p Conclusions: Increasing the amount of anaerobic interval training, stretching whilst the Muscle is fatigued, and implementing sport specific training drills resulted in a significant reduction in the number and consequences of hamstring Muscle Strain injuries.
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diagnostic and prognostic value of clinical findings in 83 athletes with posterior thigh injury comparison of clinical findings with magnetic resonance imaging documentation of hamstring Muscle Strain
American Journal of Sports Medicine, 2003Co-Authors: Geoffrey M Verrall, John P Slavotinek, Peter G BarnesAbstract:BackgroundLittle is known about the clinical features of posterior thigh injuries and their contribution to accurate diagnosis and prognostic assessment of hamstring Muscle Strain injury.HypothesesThe clinical features of posterior thigh injury can be used to diagnose hamstring Muscle Strain and to predict duration of absence from competition.Study DesignProspective clinical study.MethodsFor two playing seasons, the clinical features of posterior thigh injury, timing of injury, and playing days lost were recorded for Australian Rules football players. Magnetic resonance imaging was used to confirm hamstring Muscle injury.ResultsPosterior thigh injuries associated with pain and tenderness were recorded for 83 players, with magnetic resonance imaging confirming hamstring injury in 68 (82%). Most of the hamstring injuries were sudden onset (62; 91%) and occurred after a significant warm-up period (57; 84%). Of the patients whose injuries were sudden onset and occurred after the warm-up period (N = 59), 57 (9...
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clinical risk factors for hamstring Muscle Strain injury a prospective study with correlation of injury by magnetic resonance imaging
British Journal of Sports Medicine, 2001Co-Authors: Geoffrey M Verrall, John P Slavotinek, Peter G Barnes, G T Fon, A J SprigginsAbstract:Objective—To prospectively establish risk factors for hamstring Muscle Strain injury using magnetic resonance imaging (MRI) to define the diagnosis of posterior thigh injury. Method—In a prospective cohort study using two elite Australian Rules football clubs, the anthropometric characteristics and past clinical history of 114 athletes were recorded. Players were followed throughout the subsequent season, with posterior thigh injuries being documented. Hamstring intramuscular hyperintensity on T2 weighted MRI was required to meet our criteria for a definite hamstring injury. Statistical associations were sought between anthropometric and previous clinical characteristics and hamstring Muscle injury. Results—MRI in 32 players showed either hamstring injury (n = 26) or normal scans (n = 6). An association existed between a hamstring injury and each of the following: increasing age, being aboriginal, past history of an injury to the posterior thigh or knee or osteitis pubis (all p<0.05). These factors were still significant when players with a past history of posterior thigh injury (n = 26) were excluded. Previous back injury was associated with a posterior thigh injury that looked normal on MRI scan, but not with an MRI detected hamstring injury. Conclusions—Hamstring injuries are common in Australian football, and previous posterior thigh injury is a significant risk factor. Other factors, such as increasing age, being of aboriginal descent, or having a past history of knee injury or osteitis pubis, increase the risk of hamstring Strain independently of previous posterior thigh injury. However, as the numbers in this study are small, further research is needed before definitive statements can be made. (Br J Sports Med 2001;35:435‐440)
