Physical Therapy

The Influence of Trunk Posture on Hip and Knee Moments during Over-ground Running

A high incidence of lower extremity injuries has been reported in runners, with half of the injuries occurring at the knee joint. Sagittal plane trunk posture was shown to influence hip and knee kinetics during landing. This suggests trunk posture may be a risk factor of running injuries. The purpose of this study was aimed to examine the influence of sagittal plane trunk posture on hip and knee kinetics during running. Forty runners were recruited. Three-dimensional kinematics (250Hz, Qualisys) and ground reaction force data (1500Hz, AMTI) were collected while subjects ran with a self-selected trunk posture (speed: 3.4m/s). Mean trunk flexion angle and peak hip and knee extensor moments during the stance phase were calculated. Subjects were dichotomized into High-Flex and Low-Flex groups based on trunk flexion angles. On average, the two groups demonstrate 7.4°difference in trunk flexion. Independent t-tests showed that the Low-Flex group demonstrated significantly higher knee extensor moments and lower hip extensor moments compared to the High-Flex group. Pearson correlations showed that trunk flexion angle was positively correlated with peak hip extensor moment (r=0.44) and inversely correlated with peak knee extensor moment (r=-0.51). The results suggested a small difference in trunk flexion angle has significant influences on hip and knee kinetics. Individuals who run with a more upright trunk posture may be predisposed to a higher risk of patellar tendinopathy and patellofemoral pain. Incorporating a forward lean trunk may be utilized as an intervention strategy to reduce knee loading and risk of knee injuries in runners.


Listed In: Biomechanics, Physical Therapy, Sports Science


HIP JOINT TORQUES DURING A GOLF SWING AFTER A TOTAL HIP REPLACEMENT: A CASE SERIES

Purpose: Total Hip Replacements (THR) are common procedures for older people who suffer from degenerative joint disease. Golf is a popular leisure sport played by older Americans including those with THR. Hip torques encountered in a golf swing after THR has not been reported. The purpose of this study is to describe 3D hip joint torques generated during a golf swinging by those with THR. Methods: Three male amateur golfers who were at least 1 year post THR (ages 59-71 year old and right hand dominant, (2 were left THR) participated. Golf handicap ranged from 16-18. All participants completed the Hip Harris Score. Passive reflective markers were placed on key boney anatomical landmarks. During data collection, participants completed ten swings using a standardized driver, after a warm up. Kinetics and kinematics were captured using a 10 camera Motion Analysis system and two AMTI forceplates. Inverse dynamics procedure was used to calculate peak hip torques in all three planes. Hip torques were normalized and presented as internal torques. Comparisons were made to previously collected similarly aged senior group. Results: Average Club head velocity was slower than senior group. Sagittal Plane: THR golfers exhibited the greatest torque similar to senior group. Frontal plane: THR golfers demonstrated a lower hip adductor torque on the lead leg compared to the trail leg and senior group. Transverse plane: THR exhibited higher hip external rotation torques compared to the internal rotation torques and the senior group. Conclusion: 3-D peak hip torques generated during the golf swing by persons with a THR are greatest in the sagittal plane. THR golfers demonstrated slower club head speed but generated higher hip torques in the transverse plane as compared to those without a THR. Hip external rotation torque was higher in all of the THR compared to the senior group. Clinical Significance: Subjects with a THR may be prone to abnormal forces in the transverse plane during the golf swing. Future studies are needed to determine impact on return to golf decisions following a THR.
Listed In: Biomechanics, Physical Therapy, Sports Science