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Introduction and Objectives: Higher levels of movement or coordination variability have been reported to provide flexibility and allow adaptations to complex dynamic sport environments [1]. Decreased movement and coordination variability has been previously been reported in females [2] and proposed as a risk factor for injury. The aim of this study was to compare the variability of hip and knee joint kinematics (movement) variability and lower extremity joint and segment coupling (coordination) variability in healthy males and females during a dynamic landing task. There is a scarcity of information on gender differences in coordination and movement variability during dynamic landing and cutting tasks. This information may provide valuable insight to further explain the gender bias of ACL injury, where lower levels of movement and/or coordination variability may increase injury risk. Methods: Ten healthy males and ten healthy females were recruited for this investigation. Participants performed a dynamic task (see Figure 1) which involved dropping from a 0.30 m bench, and performing an immediate jump to touch a target and on landing perform a side cut in a randomly cued direction. Five intralimb couplings were calculated using a modified vector coding technique [3]; thigh abduction-adduction leg abduction-adduction, thigh rotation leg rotation, hip abduction-adduction knee rotation, hip rotation knee abduction-adduction, knee rotation knee abduction-adduction. Variability of the normalised coupling and joint angle timeseries was calculated point by point and averaged during the initial 40% of landing and the push off phase of cutting (70-100%). Differences in average variability were assessed using independent t-tests or Mann-Whitney U tests. Cohen's d was utilised as a measure of effect size with a 0.2=small, 0.5=moderate, >0.8=large, scale. Results: During the initial deceleration period of landing, females demonstrated significantly less movement variability at t

This study compared the lower limb coordination of the previously injured leg of ACL injured participantsparticipants (ACLr, n=18), against their non-injured leg and a control (nACL, n=18) leg. The lower limb joint and segment couplings were calculated during maximal drop-jump land and unanticipated cutting task. Differences between the previously injured and nACL control leg were present in all but one of the lower limb joint and segment couplings. Differences between the previously injured and nACL control leg were present in the hip rotation - knee abduction adduction, and knee rotation knee abduction adduction couplings. The hip and thigh were the main areas where differences were reported. Altered proximal neuromuscular function may be the origin of these altered coordination patterns.

This study compared the lower limb coordination of the previously injured leg of ACL injured participantsparticipants (ACLr, n=18), against their non-injured leg and a control (nACL, n=18) leg. The lower limb joint and segment couplings were calculated during maximal drop-jump land and unanticipated cutting task. Differences between the previously injured and nACL control leg were present in all but one of the lower limb joint and segment couplings. Differences between the previously injured and nACL control leg were present in the hip rotation - knee abduction adduction, and knee rotation knee abduction adduction couplings. The hip and thigh were the main areas where differences were reported. Altered proximal neuromuscular function may be the origin of these altered coordination patterns.

Introduction and Objectives: Higher levels of movement or coordination variability have been reported to provide flexibility and allow adaptations to complex dynamic sport environments [1]. Decreased movement and coordination variability has been previously been reported in females [2] and proposed as a risk factor for injury. The aim of this study was to compare the variability of hip and knee joint kinematics (movement) variability and lower extremity joint and segment coupling (coordination) variability in healthy males and females during a dynamic landing task. There is a scarcity of information on gender differences in coordination and movement variability during dynamic landing and cutting tasks. This information may provide valuable insight to further explain the gender bias of ACL injury, where lower levels of movement and/or coordination variability may increase injury risk. Methods: Ten healthy males and ten healthy females were recruited for this investigation. Participants performed a dynamic task (see Figure 1) which involved dropping from a 0.30 m bench, and performing an immediate jump to touch a target and on landing perform a side cut in a randomly cued direction. Five intralimb couplings were calculated using a modified vector coding technique [3]; thigh abduction-adduction leg abduction-adduction, thigh rotation leg rotation, hip abduction-adduction knee rotation, hip rotation knee abduction-adduction, knee rotation knee abduction-adduction. Variability of the normalised coupling and joint angle timeseries was calculated point by point and averaged during the initial 40% of landing and the push off phase of cutting (70-100%). Differences in average variability were assessed using independent t-tests or Mann-Whitney U tests. Cohen's d was utilised as a measure of effect size with a 0.2=small, 0.5=moderate, >0.8=large, scale. Results: During the initial deceleration period of landing, females demonstrated significantly less movement variability at t

The aim of this study was to assess the effect of the application of a previously validated golfer computer model on different levels of movement variability relative to a shot outcome measure: club head velocity. Movement variability was applied to the computer model on six measures sequentially throughout the body of the computer model. Four different levels of variability, 25%, 50%, 75% and 100% variability, were applied to x, y and z positional data of the aforementioned measures. Simulations were then performed with ADAMS/LifeMOD software for each level of movement variability applied to the measures in question. Club head velocity was measured during the simulation. The results suggest that movement variability application at these landmarks does not have an effect on outcome. These results potentially have implications for the coaching of the participant.

The aim of this study was to assess the effect of the application of a previously validated golfer computer model on different levels of movement variability relative to a shot outcome measure: club head velocity. Movement variability was applied to the computer model on six measures sequentially throughout the body of the computer model. Four different levels of variability, 25%, 50%, 75% and 100% variability, were applied to x, y and z positional data of the aforementioned measures. Simulations were then performed with ADAMS/LifeMOD software for each level of movement variability applied to the measures in question. Club head velocity was measured during the simulation. The results suggest that movement variability application at these landmarks does not have an effect on outcome. These results potentially have implications for the coaching of the participant.

This study compared the movement and coordination variability of the previously injured leg of ACL injured subjects (ACLr, n=9), against their non-injured leg and a control (nACL, n=9) leg. The variability of lower limb joint angles and couplings were calculated during a land-cut task (n=20). The previously injured leg had less variability than the noninjured leg in the knee rotation–knee abd-adduction coupling, and more variability than the nACL leg in frontal and transverse knee joint angles and hip rotation–knee abdadduction coupling. Reduced coordination variability could produce a more repetitive loading pattern linked to cartilage degeneration. Increased movement and coordination variability may stem from proprioceptive deficits on the previously injured leg and decrease the ability to adapt to perturbations.

This study compared the movement and coordination variability of the previously injured leg of ACL injured subjects (ACLr, n=9), against their non-injured leg and a control (nACL, n=9) leg. The variability of lower limb joint angles and couplings were calculated during a land-cut task (n=20). The previously injured leg had less variability than the noninjured leg in the knee rotation–knee abd-adduction coupling, and more variability than the nACL leg in frontal and transverse knee joint angles and hip rotation–knee abdadduction coupling. Reduced coordination variability could produce a more repetitive loading pattern linked to cartilage degeneration. Increased movement and coordination variability may stem from proprioceptive deficits on the previously injured leg and decrease the ability to adapt to perturbations.