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Relationship between hamstring muscle kinematics and hip rotation during the terminal swing of the sprinting gait cycle
Thursday 1 November Papers / Journal of Science and Medicine in Sport 15 (2013) S34–S126
which is a structural composite of fluid and collagen, there is some anisotropy requiring an adjustment for Poisson’s ratio. In this paper, these relationships are explored and modelled using data collected, in vivo, on human Achilles tendon. Estimates for elastic modulus and hysteresis based on speed of sound data are then compared against published values from in vitro mechanical tests. Methods: Measurements using clinical ultrasound imaging, inverse dynamics and acoustic transmission techniques were used to determine dimensions, loading conditions and longitudinal speed of sound for the Achilles tendon during a series of isometric plantar flexion exercises against body weight. Upper and lower bounds for speed of sound versus tensile stress in the tendon were then modelled and estimates derived for elastic modulus and hysteresis. Results: Axial speed of sound varied between 1850 to 2090 m.s−1 with a non-linear, asymptotic dependency on the level of tensile stress in the tendon 5–35 MPa. Estimates derived for the elastic modulus ranged between 1–2 GPa. Hysteresis derived from models of the stress-strain relationship, ranged from 3–11%. These values agree closely with those previously reported from direct measurements obtained via in vitro mechanical tensile tests on major weight bearing tendons. Discussion: There is sufficiently good agreement between these indirect (speed of sound derived) and direct (mechanical tensile test derived) measures of tendon mechanical properties to validate the use of this non-invasive acoustic transmission technique. This non-invasive method is suitable for monitoring changes in tendon properties as predictors of athletic performance, injury or therapeutic progression.
Results: The peak length of the BF, ST, and SM was seen at 82.8 (1.9) %, 77.5 (2.5) %, and 80.0 (2.8) % of the running gait cycle, respectively. The peak hip internal rotation angle during the terminal swing was seen at 83.0 (3.8) % of the running cycle, which was significantly different from the time of the peak ST length (p < 0.01), but not significantly different from that of the peak BF and SM lengths. Peak hip flexion was seen at 75.3 (2.4) % of the running cycle, which was significantly different from the time of the peak BF and SM lengths (p < 0.001 and p < 0.01, respectively), but not significantly different from that of the peak ST length. A similar trend was observed for the muscle-tendon forces of the hamstring muscles. Discussion: The results showed that the peak muscle lengths and muscle-tendon forces of the BF and SM were synchronous with the peak internal rotation angle of the hip. Hip internal rotation may influence susceptibility to the stretching of the BF and SM muscles, whose time of peak length and muscle-tendon force is considerably different from those of the ST. http://dx.doi.org/10.1016/j.jsams.2012.11.152 150 Declines in eccentric knee flexor weakness following repeat sprint running are related to declines in biceps femoris voluntary activation R. Timmins 1,∗ , D. Opar 1 , N. Dear 1 , M. Williams 2 , A. Shield 1 1 2
http://dx.doi.org/10.1016/j.jsams.2012.11.151 149 Relationship between hamstring muscle kinematics and hip rotation during the terminal swing of the sprinting gait cycle A. Higashihara 1,2,∗ , Y. Nagano 3 , K. Takahashi 3 , T. Fukubayashi 4 1
Graduate School of Sport Sciences, Waseda University The Japan Society for the Promotion of Science 3 Niigata University of Health and Welfare 4 Faculty of Sport Sciences, Waseda University 2
Introduction: Recently, video analysis of hamstring strain injury suggested that forward lean of the trunk, flexion of the hip, and extension of the knee cause stretching of the hamstring muscles. We hypothesized that, in addition to these observations, hip rotation also contributes to injury and, further, influences the difference in injury rates among the hamstring muscles. The purpose of this study was to examine the relationship between hamstring muscle kinematics and hip rotation during the terminal swing of the sprinting gait cycle. Methods: Eight male sprinters (age, 19.4 (2.4) years) performed maximal sprint from the starting line, approximately 60 m away from the center of the measurement area. We obtained three-dimensional kinematics during 1 running cycle. These data were used to drive musculoskeletal models using nMotion musculous (NAC Image Technology Inc., JAPAN). Muscle length and muscle-tendon force were calculated for the biceps femoris (BF), semitendinosus (ST), and semimembranosus (SM). Hip flexion and internal rotation angles were also calculated. The time of peak muscle length and muscle-tendon force in terms of the percent of the running gait cycle were measured and compared with that of flexion and internal rotation angles of the hip using the Bonferroni multiple comparison test.
S63
Queensland University of Technology University of Glamorgan, Pontypridd, Wales
Introduction: Hamstring strain injuries (HSI) are the predominant non-contact injury in many sports. Eccentric hamstring muscle weakness following intermittent running has been implicated within the aetiology of HSI. This weakness following intermittent running is sometimes greater eccentrically than concentrically, however the cause of this unique, contraction mode specific phenomenon is unknown. The purpose of this research was to determine whether declines in knee flexor strength following overground repeat sprints are caused by declines in voluntary activation of the hamstring muscles. Methods: Seventeen recreationally active males completed 3 sets of 6 by 20 m overground sprints. Maximal isokinetic concentric and eccentric knee flexor and concentric knee extensor strength was determined at ± 1800 .s−1 and ± 600.s−1 while hamstring muscle activation was assessed using surface electromyography, before and 15 minutes after the running protocol. Results: Overground repeat sprint running resulted in a significant decline in eccentric knee flexor strength (31.1 Nm; 95% CI = 21.8 to 40.3 Nm; p < 0.001). However, concentric knee flexor strength was not significantly altered (11.1 Nm; 95% CI = -2.8 to 24.9; p = 0.2294). Biceps femoris voluntary activation levels displayed a significant decline eccentrically (0.067; 95% CI = 0.002 to 0.063; p = 0.0325). However, there was no significant decline concentrically (0.025; 95% CI = -0.018 to 0.043; p = 0.4243) following sprinting. Furthermore, declines in average peak torque at -1800 .s−1 could be explained by changes in hamstring activation (R2 = 0.70). Moreover, it was change in the lateral hamstring muscle activity that was related to the decrease in knee flexor torque (p = 0.0144). In comparison, medial hamstring voluntary activation showed no change for either eccentric (0.06; 95% CI = -0.033 to 0.102; p = 0.298) or concentric (0.09; 95% CI = -0.03 to 0.16; p = 0.298) muscle actions following repeat sprinting. Discussion: Eccentric hamstring strength is decreased significantly following overground repeat sprinting. Voluntary activation
which is a structural composite of fluid and collagen, there is some anisotropy requiring an adjustment for Poisson’s ratio. In this paper, these relationships are explored and modelled using data collected, in vivo, on human Achilles tendon. Estimates for elastic modulus and hysteresis based on speed of sound data are then compared against published values from in vitro mechanical tests. Methods: Measurements using clinical ultrasound imaging, inverse dynamics and acoustic transmission techniques were used to determine dimensions, loading conditions and longitudinal speed of sound for the Achilles tendon during a series of isometric plantar flexion exercises against body weight. Upper and lower bounds for speed of sound versus tensile stress in the tendon were then modelled and estimates derived for elastic modulus and hysteresis. Results: Axial speed of sound varied between 1850 to 2090 m.s−1 with a non-linear, asymptotic dependency on the level of tensile stress in the tendon 5–35 MPa. Estimates derived for the elastic modulus ranged between 1–2 GPa. Hysteresis derived from models of the stress-strain relationship, ranged from 3–11%. These values agree closely with those previously reported from direct measurements obtained via in vitro mechanical tensile tests on major weight bearing tendons. Discussion: There is sufficiently good agreement between these indirect (speed of sound derived) and direct (mechanical tensile test derived) measures of tendon mechanical properties to validate the use of this non-invasive acoustic transmission technique. This non-invasive method is suitable for monitoring changes in tendon properties as predictors of athletic performance, injury or therapeutic progression.
Results: The peak length of the BF, ST, and SM was seen at 82.8 (1.9) %, 77.5 (2.5) %, and 80.0 (2.8) % of the running gait cycle, respectively. The peak hip internal rotation angle during the terminal swing was seen at 83.0 (3.8) % of the running cycle, which was significantly different from the time of the peak ST length (p < 0.01), but not significantly different from that of the peak BF and SM lengths. Peak hip flexion was seen at 75.3 (2.4) % of the running cycle, which was significantly different from the time of the peak BF and SM lengths (p < 0.001 and p < 0.01, respectively), but not significantly different from that of the peak ST length. A similar trend was observed for the muscle-tendon forces of the hamstring muscles. Discussion: The results showed that the peak muscle lengths and muscle-tendon forces of the BF and SM were synchronous with the peak internal rotation angle of the hip. Hip internal rotation may influence susceptibility to the stretching of the BF and SM muscles, whose time of peak length and muscle-tendon force is considerably different from those of the ST. http://dx.doi.org/10.1016/j.jsams.2012.11.152 150 Declines in eccentric knee flexor weakness following repeat sprint running are related to declines in biceps femoris voluntary activation R. Timmins 1,∗ , D. Opar 1 , N. Dear 1 , M. Williams 2 , A. Shield 1 1 2
http://dx.doi.org/10.1016/j.jsams.2012.11.151 149 Relationship between hamstring muscle kinematics and hip rotation during the terminal swing of the sprinting gait cycle A. Higashihara 1,2,∗ , Y. Nagano 3 , K. Takahashi 3 , T. Fukubayashi 4 1
Graduate School of Sport Sciences, Waseda University The Japan Society for the Promotion of Science 3 Niigata University of Health and Welfare 4 Faculty of Sport Sciences, Waseda University 2
Introduction: Recently, video analysis of hamstring strain injury suggested that forward lean of the trunk, flexion of the hip, and extension of the knee cause stretching of the hamstring muscles. We hypothesized that, in addition to these observations, hip rotation also contributes to injury and, further, influences the difference in injury rates among the hamstring muscles. The purpose of this study was to examine the relationship between hamstring muscle kinematics and hip rotation during the terminal swing of the sprinting gait cycle. Methods: Eight male sprinters (age, 19.4 (2.4) years) performed maximal sprint from the starting line, approximately 60 m away from the center of the measurement area. We obtained three-dimensional kinematics during 1 running cycle. These data were used to drive musculoskeletal models using nMotion musculous (NAC Image Technology Inc., JAPAN). Muscle length and muscle-tendon force were calculated for the biceps femoris (BF), semitendinosus (ST), and semimembranosus (SM). Hip flexion and internal rotation angles were also calculated. The time of peak muscle length and muscle-tendon force in terms of the percent of the running gait cycle were measured and compared with that of flexion and internal rotation angles of the hip using the Bonferroni multiple comparison test.
S63
Queensland University of Technology University of Glamorgan, Pontypridd, Wales
Introduction: Hamstring strain injuries (HSI) are the predominant non-contact injury in many sports. Eccentric hamstring muscle weakness following intermittent running has been implicated within the aetiology of HSI. This weakness following intermittent running is sometimes greater eccentrically than concentrically, however the cause of this unique, contraction mode specific phenomenon is unknown. The purpose of this research was to determine whether declines in knee flexor strength following overground repeat sprints are caused by declines in voluntary activation of the hamstring muscles. Methods: Seventeen recreationally active males completed 3 sets of 6 by 20 m overground sprints. Maximal isokinetic concentric and eccentric knee flexor and concentric knee extensor strength was determined at ± 1800 .s−1 and ± 600.s−1 while hamstring muscle activation was assessed using surface electromyography, before and 15 minutes after the running protocol. Results: Overground repeat sprint running resulted in a significant decline in eccentric knee flexor strength (31.1 Nm; 95% CI = 21.8 to 40.3 Nm; p < 0.001). However, concentric knee flexor strength was not significantly altered (11.1 Nm; 95% CI = -2.8 to 24.9; p = 0.2294). Biceps femoris voluntary activation levels displayed a significant decline eccentrically (0.067; 95% CI = 0.002 to 0.063; p = 0.0325). However, there was no significant decline concentrically (0.025; 95% CI = -0.018 to 0.043; p = 0.4243) following sprinting. Furthermore, declines in average peak torque at -1800 .s−1 could be explained by changes in hamstring activation (R2 = 0.70). Moreover, it was change in the lateral hamstring muscle activity that was related to the decrease in knee flexor torque (p = 0.0144). In comparison, medial hamstring voluntary activation showed no change for either eccentric (0.06; 95% CI = -0.033 to 0.102; p = 0.298) or concentric (0.09; 95% CI = -0.03 to 0.16; p = 0.298) muscle actions following repeat sprinting. Discussion: Eccentric hamstring strength is decreased significantly following overground repeat sprinting. Voluntary activation