Purpose: Total Hip Replacements (THR) are a common procedure for older people who suffer from degenerative joint disease. Golf is a very popular leisure sport played by many 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 three- dimensional (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. Participants were allowed to warm up prior to testing by performing golf swings. During data collection, participants completed ten swings using a standardized driver. Kinetics and kinematics were captured using a 10 camera Motion Analysis system (Motion Analysis Corp, Santa Rose, CA) and two AMTI (Advanced Medical Technology, Inc., Watertown, MA) forceplates. Inverse dynamics procedure was used to calculate peak hip torques in all three planes. Hip torques were normalized to body weight x height (BW x Ht) and presented as internal torques. Comparisons were made to previously collected similarly aged healthy male golfers (senior group). Results: Average Club head velocity was slower than senior group. Like the senior group, THR golfers exhibited the greatest torque in the sagittal plane .In the frontal plane, all THR golfers demonstrated a lower hip adductor torque on the lead leg compared to the trail leg and compared to senior group. In the transverse plane, those with THR exhibited higher hip external rotation torques compared to the internal rotation torques and compared to the senior group. Conclusion: Three dimensional 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.

Osteoarthritis (OA) is a chronic joint disease, the most common musculoskeletal complaint worldwide, and is associated with significant health and welfare costs. Previous research indicates that co-activation of muscles may lead to the onset of knee OA. Therefore, investigation of muscle recruitment patterns and neuromuscular efficiency in healthy individuals compared to patients with knee OA in simple closed chain exercises using electromyography (EMG), motion analysis system and force plates may lead to a better understanding of how knee OA develops (6). The present studies chosen were in the frontal plane while performing lateral step up and step down tasks for a 4 inch and 8 inch step height. In the stepping tasks it was discovered that there is a greater magnitude EMG and ground reaction force (GRF) for 8 inch rather than a 4 inch step. Additionally, a higher activation of gluteus medius, gluteus maximus and quadriceps muscles (rectus femoris , vastus lateralis , vastus medius) was revealed in both the stepping tasks.

Functional activities in daily life often require shifting body weight toward one limb, from a more even double leg stance. Stability of the knee is challenged in people with total knee replacement (TKR) when weight shifting also includes transverse plane rotation. Our study utilized a novel approach in order to facilitate transfer of load to one extremity during squatting or extending in double-stance. The objective of this study was to identify strategies utilized by individuals with TKR in double-stance transferring load during rotation and flexion. Twelve subjects of an ongoing study were selected (6 TKR, 6 healthy). Each subject completed a custom crossover button push task where rotation, flexion, extension of the knee were utilized. Each subject performed two crossover reaching tasks, a High to Low (H2L) and Low to High (L2H). The subject stood on two AMTI force platforms obtaining ground reaction force, which were then converted to lead force ratios. Knee flexion angles were also recorded. The TKR subjects had less ratio throughout the L2H movement compared to healthy. In contrast, the TKR subjects had a greater load transfer throughout the H2L compared to healthy. Large variation at mid-flexion in TKR subjects suggested possible difficulty in maintaining positional stability during these tasks. The TKR subjects maintained more of an extended knee, suggesting rotation was achieved by a strategy and knee extension is a more ‘stable’. Early identification and correction of these strategies could improve TKR success and return to activities of daily living that involve flexion and rotation.

Few studies have quantified the improvements in motor coordination after Tai Chi (TC) training in Parkinson Disease (PD). Further, given that people with PD have difficulties with balance while performing a secondary task, interventions that involve dual-task components are needed. We investigated whether TC improved their postural control under secondary cognitive/motor task condition in persons with PD. Eleven participants with PD completed the 16-week TC training, and were compared to five non-exercise PD controls. During baseline testing, each participant stood for 10 seconds on a force platform and held a set of two cylinders stacked together. Center of pressure excursion was collected at 360Hz under three task conditions: static (holding objects), secondary cognitive (a digit subtraction while holding objects), and secondary motor (pulling the top cylinder apart). Participants underwent the same baseline tests following the 16-week period. The change score after 16 weeks in Approximate entropy (ApEn) on anteroposterior (A/P) and mediolateral (M/L) directions and 95% confidence ellipse (Area95) were evaluated using independent t-test in each condition. After 16 weeks, TC participants reduced their Area95 (-.05±.57cm2) in static condition when compared to the control group (+.73±.78cm2, p<.05). Change in ApEn in TC participants (A/P: +.12±.35, M/L: -.01±.23) did not significantly differ from the control group (A/P: +.07±.23, M/L: +.10±.23). No significant differences were observed in any of two secondary task conditions. In conclusion, Tai Chi intervention appears to be effective for persons with PD to improve their postural control under cognitively less challenging condition. However, this benefit could not be reflected in postural control while performing a secondary task.