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Jörn Rittweger - One of the best experts on this subject based on the ideXlab platform.
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Mechano-adaptation of bone: Are all strains equal?
2016Co-Authors: Jörn RittwegerAbstract:Bone research has been re-directed in the 1990s by three revolutions: firstly the recognition that bones respond to changes in their mechanical environment in a dose-dependent way; secondly by the idea that these changes in bone size can be understood as self-adaptation to variant forces by a servo-control mechanism (mechanostat theory); and thirdly by the proposition that muscles ‘enslave’ bone’s mechan-adaptation. It has been an inherent assumption in most of these bone studies that bone deformations mostly result from bending and compression, and little to no attention was paid to Torsional loading. Notably, axial strains dominate in axial loading, whilst Torsional loading is associated with relatively large shear strains. To better understand the mechanical interplay between regional muscle contractions and bone deformations, my team performed the MUST-study: bone pins were inserted into the human Tibia, and non-collinear retro-reflective marker clusters were affixed to these pins in order to assess translational and rotational Tibia deformations. Results from that study revealed that Torsion is a prevailing deformation type within the human Tibia, and that Tibia Torsion is causally linked to calf muscle contractions. Simultaneously, a series of in-silico experiments in our lab with a mechanostat model were undertaken. They revealed that Torsion (i) is the most effective mode of bone deformation, and (ii) that it can explain the so-called flexure neutralization of miss-aligned fractures, which is inexplicable on grounds of compression and bending alone. Moreover, recent data also suggest that Torsion, rather than impact may the bone-effective agent in the side-differences encountered in tennis players and baseball pitchers. Thus, I am currently following the idea of Torsion as an effective deformation mode to elicit bone-anabolic responses. This is in contradiction to the main stream in bone research, which still regards impact loading as the most efficient way. Understanding and settling this question will be important in order to provide optimized exercise prescriptions that will maximize the benefits for bone, and minimize adverse events, such as joint sprains, cartilage damage, and tendon problems.
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Torsion and Antero-Posterior Bending in the In Vivo Human Tibia Loading Regimes during Walking and Running
PloS one, 2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:Bending, in addition to compression, is recognized to be a common loading pattern in long bones in animals. However, due to the technical difficulty of measuring bone deformation in humans, our current understanding of bone loading patterns in humans is very limited. In the present study, we hypothesized that bending and Torsion are important loading regimes in the human Tibia. In vivo Tibia segment deformation in humans was assessed during walking and running utilizing a novel optical approach. Results suggest that the proximal Tibia primarily bends to the posterior (bending angle: 0.15°–1.30°) and medial aspect (bending angle: 0.38°–0.90°) and that it twists externally (Torsion angle: 0.67°–1.66°) in relation to the distal Tibia during the stance phase of overground walking at a speed between 2.5 and 6.1 km/h. Peak posterior bending and peak Torsion occurred during the first and second half of stance phase, respectively. The peak-to-peak antero-posterior (AP) bending angles increased linearly with vertical ground reaction force and speed. Similarly, peak-to-peak Torsion angles increased with the vertical free moment in four of the five test subjects and with the speed in three of the test subjects. There was no correlation between peak-to-peak medio-lateral (ML) bending angles and ground reaction force or speed. On the treadmill, peak-to-peak AP bending angles increased with walking and running speed, but peak-to-peak Torsion angles and peak-to-peak ML bending angles remained constant during walking. Peak-to-peak AP bending angle during treadmill running was speed-dependent and larger than that observed during walking. In contrast, peak-to-peak Tibia Torsion angle was smaller during treadmill running than during walking. To conclude, bending and Torsion of substantial magnitude were observed in the human Tibia during walking and running. A systematic distribution of peak amplitude was found during the first and second parts of the stance phase.
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Tibia segment deformation angles during walking and running on a treadmill at different speed.
2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:A: Tibia AP bending angles at different speed of walking and running. B: Tibia Torsion angle. C: Tibia ML bending angle. *: p
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The demonstration of the human shank, the Tibia posterior bending angle and Torsion angle.
2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:A: anatomy of human shank. B: the demonstration of the posterior bending of the proximal Tibia. αpos indicates the posterior bending angle. C: Tibia Torsion deformation. βtor indicates the internal Torsion angle whist the Tibia is twisted.
Peng-fei Yang - One of the best experts on this subject based on the ideXlab platform.
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Torsion and Antero-Posterior Bending in the In Vivo Human Tibia Loading Regimes during Walking and Running
PloS one, 2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:Bending, in addition to compression, is recognized to be a common loading pattern in long bones in animals. However, due to the technical difficulty of measuring bone deformation in humans, our current understanding of bone loading patterns in humans is very limited. In the present study, we hypothesized that bending and Torsion are important loading regimes in the human Tibia. In vivo Tibia segment deformation in humans was assessed during walking and running utilizing a novel optical approach. Results suggest that the proximal Tibia primarily bends to the posterior (bending angle: 0.15°–1.30°) and medial aspect (bending angle: 0.38°–0.90°) and that it twists externally (Torsion angle: 0.67°–1.66°) in relation to the distal Tibia during the stance phase of overground walking at a speed between 2.5 and 6.1 km/h. Peak posterior bending and peak Torsion occurred during the first and second half of stance phase, respectively. The peak-to-peak antero-posterior (AP) bending angles increased linearly with vertical ground reaction force and speed. Similarly, peak-to-peak Torsion angles increased with the vertical free moment in four of the five test subjects and with the speed in three of the test subjects. There was no correlation between peak-to-peak medio-lateral (ML) bending angles and ground reaction force or speed. On the treadmill, peak-to-peak AP bending angles increased with walking and running speed, but peak-to-peak Torsion angles and peak-to-peak ML bending angles remained constant during walking. Peak-to-peak AP bending angle during treadmill running was speed-dependent and larger than that observed during walking. In contrast, peak-to-peak Tibia Torsion angle was smaller during treadmill running than during walking. To conclude, bending and Torsion of substantial magnitude were observed in the human Tibia during walking and running. A systematic distribution of peak amplitude was found during the first and second parts of the stance phase.
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Tibia segment deformation angles during walking and running on a treadmill at different speed.
2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:A: Tibia AP bending angles at different speed of walking and running. B: Tibia Torsion angle. C: Tibia ML bending angle. *: p
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The demonstration of the human shank, the Tibia posterior bending angle and Torsion angle.
2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:A: anatomy of human shank. B: the demonstration of the posterior bending of the proximal Tibia. αpos indicates the posterior bending angle. C: Tibia Torsion deformation. βtor indicates the internal Torsion angle whist the Tibia is twisted.
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Relation of muscular contractions to mechanical deformation in the human Tibia during different locomotive activities
2013Co-Authors: Peng-fei YangAbstract:Abstract Bone deformation is widely accepted as one of the most important factors in bone adaptation. It was hypothesized that the largest load on bone is primarily caused by muscle forces. Nevertheless, in vivo bone deformation amplitude and regimes measurements are still technically challenging, especially in humans. Furthermore, the relationship between the local muscle activities and the bone loading pattern remained largely unclear. Therefore, taking human shank as an object, one of the purposes of the present thesis was to investigate the Tibia loading regimes, in terms of Tibia segment deformation pattern, during different locomotor activities in humans. Moreover, the role of calf muscle activities in Tibia deformation regimes was further examined. Utilizing a novel optical segment tracking (OST) approach, the in vivo Tibia segment deformation regimes in five male volunteers were investigated during walking, running, stair ascent and isometric muscle contraction. The reliability study of the OST approach suggested that the OST approach is capable of assessing in vivo Tibia deformation regimes with high resolution, accuracy and repeatability. Most importantly, the surgical procedure of the entire experiments was well tolerated by the test subjects. During the stance phase of walking, results suggested that the proximal Tibia primarily bends to the posterior aspect, medial aspect and twists to the external aspect with respect to distal Tibia. The peak to peak (p2p) antero-posterior (AP) bending angles increased linearly with the vertical ground reaction force and speed, respectively. Similarly, p2p Torsion angles increased with the vertical free moment. However, the exact relationship between the Tibia deformation and reaction force or moment was different between individuals. P2p AP bending angle during treadmill running was speed-dependant and larger than walking. In contrast, p2p Tibia Torsion angle was smaller during treadmill running than walking. Furthermore, peak posterior bending and peak Torsion occurred during the first half (21%-22%) and second half (72%-76%) of the stance phase of walking, respectively. Two noticeable peaks of Torsion with forefoot contact (38% and 82% of stance phase), but only one peak of Torsion with full foot contact (78% of stance phase) were found during stair ascent. The peak-to-peak Torsion angle was larger with forefoot contact than full foot contact during both the stance phase of stair ascent and running. The Tibia deformation regimes were characterized mostly by Torsion than bending during isometric plantar flexion. To conclude, bending and Torsion predominated the Tibia deformation regimes during the investigated activities. The relationship of Tibia deformation with locomotor speed and ground reaction forces bears highly individual-related information. Unexpectedly large Torsional deformation was induced by forefoot exercises and isometric contraction. Together with the specific fixed phase relationship between Torsional deformation angles and local muscle activities, it seems that Tibia Torsion deformation is closely related to the local muscle contractions. It thus can be speculated that the Torsional deformation might be another candidate, besides the compression and tension, to drive the long bone adaptation. Zusammenfassung Knochenverformung ist weitgehend anerkannt als einer der wichtigsten Faktoren bei Knochenanpassungsvorgangen. Man nimmt an, dass die grosten Lasten auf den Knochen vorrangig durch Muskelkrafte verursacht werden. Nichtsdestoweniger sind Messungen in vivo von Knochendeformationen in Amplitude und in den verschiedenen Verformungs-Regimes immer noch eine grose Herausforderung, insbesondere beim Menschen. Daruber hinaus war bisher die Beziehung zwischen lokaler Muskelaktivitat und dem Muster der Knochenbelastung weitestgehend unklar. Eines der Ziele der vorliegenden Thesis war daher, am Beispiel des menschlichen Schienbeins die unterschiedlichen Last-Falle der Tibia bei unterschiedlichen Fortbewegungs-Aktivitaten im Menschen zu untersuchen, und zwar in Form von Verformungsmustern von Tibia-Segmenten. Zusatzlich wurde die Rolle der Wadenmuskelaktivitat fur die Tibiaverformung untersucht. Ein neuartiger Ansatz zur optischen Segment-Verfolgung (optical segment tracking, OST) kam zum Einsatz, um in vivo die Tibia Segment-Verformung von 5 mannlichen Freiwilligen beim Gehen, Laufen, Treppensteigen und bei isometrischer Muskelkontraktion zu untersuchen. Eine Zuverlassigkeitsstudie zur OST-Methodik ergab, dass diese Methode in der Lage ist, die Tibia-Verformung in vivo in hoher Auflosung, Genauigkeit und Wiederholbarkeit darzustellen. Die chirurgischen Eingriffe der gesamten Experimente wurden von den Probanden gut vertragen. Die Ergebnisse deuten darauf hin, dass sich wahrend der Stand-Phase beim Gehen die proximale Tibia vornehmlich in posteriale und mediale Richtung biegt sowie in externale Richtung in Bezug auf die distale Tibia verdreht. Die Amplitude der „peak to peak (p2p)“ antero-posterioe (AP) Biegewinkel stieg linear mit vertikaler Bodenreaktionskraft und Geschwindigkeit. Ahnlich vergroserten sich die p2p Torsionswinkel mit dem vertikalen freien Drehmoment. Die genaue Beziehung zwischen Tibiaverformung Reaktionskraft oder –drehmoment war jedoch interindividuell unterschiedlich. Der P2p AP Biegungswinkel wahrend des Laufens auf dem Laufband war geschwindigkeitsabhangig und groser als beim Gehen. Im Gegensatz dazu war der p2p Torsionswinkel der Tibia beim Laufen kleiner als beim Gehen. Die Maxima der posterialen Biegung und der Torsion fielen in die erste Halfte (21%-22%) und entsprechend in die zweite Halfte (72%-76%) der Standphase beim Gehen. Zwei ausgepragte Maxima der Torsion bei vollem Fus-Kontakt (78% Standphase) traten beim Treppensteigen auf. Der p2p Torsionswinkel war groser bei Vorderfus-Kontakt als bei vollem Fuskontakt wahrend der Standphase sowohl bei Treppensteigen als auch beim Laufen. Die Tibiaverformung wahrend der isometrischen Plantarflexion war mehr durch Torsion als durch Biegung charakterisiert. Zusammenfassend kann man sagen, dass bei den untersuchten Aktivitaten Biegung und Torsion bei der Tibiaverformung vorherrschten. Die Beziehung zwischen Tibiadeformation einerseits und Fortbewegungsgeschwindigkeit und Bodenreaktionskraften andererseits birgt hochgradig individuumbezogene Informationen. Unerwartet hohe Torsionsdeformation wurde durch Vorderfus-Ubungen und durch isometrische Kontraktion hervorgerufen. Zusammen gesehen mit der auffalligen Beziehung zwischen den Phasen des Torsionswinkels und der lokalen Muskelaktivitaten scheint die Torsionale Deformation der Tibia eng verbunden zu sein mit den lokalen Muskelkontraktionen. Man kann spekulieren, dass die Torsionale Verformung neben Kompression und Dehnung ein weiterer Treiber bei der Anpassung von Rohrenknochen ist.
Maximilian Sanno - One of the best experts on this subject based on the ideXlab platform.
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Torsion and Antero-Posterior Bending in the In Vivo Human Tibia Loading Regimes during Walking and Running
PloS one, 2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:Bending, in addition to compression, is recognized to be a common loading pattern in long bones in animals. However, due to the technical difficulty of measuring bone deformation in humans, our current understanding of bone loading patterns in humans is very limited. In the present study, we hypothesized that bending and Torsion are important loading regimes in the human Tibia. In vivo Tibia segment deformation in humans was assessed during walking and running utilizing a novel optical approach. Results suggest that the proximal Tibia primarily bends to the posterior (bending angle: 0.15°–1.30°) and medial aspect (bending angle: 0.38°–0.90°) and that it twists externally (Torsion angle: 0.67°–1.66°) in relation to the distal Tibia during the stance phase of overground walking at a speed between 2.5 and 6.1 km/h. Peak posterior bending and peak Torsion occurred during the first and second half of stance phase, respectively. The peak-to-peak antero-posterior (AP) bending angles increased linearly with vertical ground reaction force and speed. Similarly, peak-to-peak Torsion angles increased with the vertical free moment in four of the five test subjects and with the speed in three of the test subjects. There was no correlation between peak-to-peak medio-lateral (ML) bending angles and ground reaction force or speed. On the treadmill, peak-to-peak AP bending angles increased with walking and running speed, but peak-to-peak Torsion angles and peak-to-peak ML bending angles remained constant during walking. Peak-to-peak AP bending angle during treadmill running was speed-dependent and larger than that observed during walking. In contrast, peak-to-peak Tibia Torsion angle was smaller during treadmill running than during walking. To conclude, bending and Torsion of substantial magnitude were observed in the human Tibia during walking and running. A systematic distribution of peak amplitude was found during the first and second parts of the stance phase.
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Tibia segment deformation angles during walking and running on a treadmill at different speed.
2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:A: Tibia AP bending angles at different speed of walking and running. B: Tibia Torsion angle. C: Tibia ML bending angle. *: p
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The demonstration of the human shank, the Tibia posterior bending angle and Torsion angle.
2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:A: anatomy of human shank. B: the demonstration of the posterior bending of the proximal Tibia. αpos indicates the posterior bending angle. C: Tibia Torsion deformation. βtor indicates the internal Torsion angle whist the Tibia is twisted.
Bergita Ganse - One of the best experts on this subject based on the ideXlab platform.
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Torsion and Antero-Posterior Bending in the In Vivo Human Tibia Loading Regimes during Walking and Running
PloS one, 2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:Bending, in addition to compression, is recognized to be a common loading pattern in long bones in animals. However, due to the technical difficulty of measuring bone deformation in humans, our current understanding of bone loading patterns in humans is very limited. In the present study, we hypothesized that bending and Torsion are important loading regimes in the human Tibia. In vivo Tibia segment deformation in humans was assessed during walking and running utilizing a novel optical approach. Results suggest that the proximal Tibia primarily bends to the posterior (bending angle: 0.15°–1.30°) and medial aspect (bending angle: 0.38°–0.90°) and that it twists externally (Torsion angle: 0.67°–1.66°) in relation to the distal Tibia during the stance phase of overground walking at a speed between 2.5 and 6.1 km/h. Peak posterior bending and peak Torsion occurred during the first and second half of stance phase, respectively. The peak-to-peak antero-posterior (AP) bending angles increased linearly with vertical ground reaction force and speed. Similarly, peak-to-peak Torsion angles increased with the vertical free moment in four of the five test subjects and with the speed in three of the test subjects. There was no correlation between peak-to-peak medio-lateral (ML) bending angles and ground reaction force or speed. On the treadmill, peak-to-peak AP bending angles increased with walking and running speed, but peak-to-peak Torsion angles and peak-to-peak ML bending angles remained constant during walking. Peak-to-peak AP bending angle during treadmill running was speed-dependent and larger than that observed during walking. In contrast, peak-to-peak Tibia Torsion angle was smaller during treadmill running than during walking. To conclude, bending and Torsion of substantial magnitude were observed in the human Tibia during walking and running. A systematic distribution of peak amplitude was found during the first and second parts of the stance phase.
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Tibia segment deformation angles during walking and running on a treadmill at different speed.
2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:A: Tibia AP bending angles at different speed of walking and running. B: Tibia Torsion angle. C: Tibia ML bending angle. *: p
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The demonstration of the human shank, the Tibia posterior bending angle and Torsion angle.
2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:A: anatomy of human shank. B: the demonstration of the posterior bending of the proximal Tibia. αpos indicates the posterior bending angle. C: Tibia Torsion deformation. βtor indicates the internal Torsion angle whist the Tibia is twisted.
Timmo Koy - One of the best experts on this subject based on the ideXlab platform.
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Torsion and Antero-Posterior Bending in the In Vivo Human Tibia Loading Regimes during Walking and Running
PloS one, 2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:Bending, in addition to compression, is recognized to be a common loading pattern in long bones in animals. However, due to the technical difficulty of measuring bone deformation in humans, our current understanding of bone loading patterns in humans is very limited. In the present study, we hypothesized that bending and Torsion are important loading regimes in the human Tibia. In vivo Tibia segment deformation in humans was assessed during walking and running utilizing a novel optical approach. Results suggest that the proximal Tibia primarily bends to the posterior (bending angle: 0.15°–1.30°) and medial aspect (bending angle: 0.38°–0.90°) and that it twists externally (Torsion angle: 0.67°–1.66°) in relation to the distal Tibia during the stance phase of overground walking at a speed between 2.5 and 6.1 km/h. Peak posterior bending and peak Torsion occurred during the first and second half of stance phase, respectively. The peak-to-peak antero-posterior (AP) bending angles increased linearly with vertical ground reaction force and speed. Similarly, peak-to-peak Torsion angles increased with the vertical free moment in four of the five test subjects and with the speed in three of the test subjects. There was no correlation between peak-to-peak medio-lateral (ML) bending angles and ground reaction force or speed. On the treadmill, peak-to-peak AP bending angles increased with walking and running speed, but peak-to-peak Torsion angles and peak-to-peak ML bending angles remained constant during walking. Peak-to-peak AP bending angle during treadmill running was speed-dependent and larger than that observed during walking. In contrast, peak-to-peak Tibia Torsion angle was smaller during treadmill running than during walking. To conclude, bending and Torsion of substantial magnitude were observed in the human Tibia during walking and running. A systematic distribution of peak amplitude was found during the first and second parts of the stance phase.
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Tibia segment deformation angles during walking and running on a treadmill at different speed.
2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:A: Tibia AP bending angles at different speed of walking and running. B: Tibia Torsion angle. C: Tibia ML bending angle. *: p
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The demonstration of the human shank, the Tibia posterior bending angle and Torsion angle.
2014Co-Authors: Peng-fei Yang, Maximilian Sanno, Bergita Ganse, Timmo Koy, Gert-peter Brüggemann, Lars Peter Müller, Jörn RittwegerAbstract:A: anatomy of human shank. B: the demonstration of the posterior bending of the proximal Tibia. αpos indicates the posterior bending angle. C: Tibia Torsion deformation. βtor indicates the internal Torsion angle whist the Tibia is twisted.