The kinematic differences between individuals with patellofemoral pain and matched controls during a single leg squat

[摘要] ENGLISH SUMMARY : Background: Patellofemoral pain (PFP) is a common knee condition characterised by retro- or peripatellar pain. It affects 11 percent of people who consult a general practitioner for knee pain. This condition has an impact on the daily lives of those suffering from it and causes pain duringactivities such as stair climbing, squatting and prolonged sitting. PFP has the tendency to become chronic. Altered lower limb and trunk kinematics may play an important role in the development of PFP and can be evaluated during a single leg squat (SLS). Findings regardingthe kinematics of individuals with PFP compared to controls during a SLS are limited and inconsistent.Objective: The objective of the study was to describe the lower limb and trunk kinematic differences between individuals with PFP and matched controls during a SLS.Methodology: A cross-sectional design was followed in this study. The study was conducted in a laboratory setting in the Neuromechanics unit of the Central Analytical Facility of Stellenbosch University at the Coetzenburg Sports Complex, Stellenbosch. Study participants included 26 cases with PFP and 26 healthy gender- and age-matched controls. The Vicon 3D motion analysis system was utilised to capture the peak values of all outcomes (ipsilateral trunk lean, contralateral pelvic drop, hip adduction, knee abduction, rear-foot eversion, hip internal rotation and knee external rotation) during the static phase of the SLS. The kinematic outcomes of cases and controls were compared using the paired t-test.Results: The study population comprised 16 females and 10 males with PFP and their respective control group participants. The PFP group had a mean age of 28.5 years compared to 28 years for thecontrol group. Participants with PFP presented with significantly more peak knee external rotation compared to healthy controls during the static phase of the SLS (MD, 4.68˚; 95% CI: 2.83, 6.53; p < 0.001). This also was the case when the groups were stratified for gender. When stratified for bilateral and unilateral PFP, only the bilateral PFP group demonstrated significantly increased peak knee external rotation compared to their control group, with a mean difference of 5.98˚ (95% CI: 3.79, 8.17; p < 0.001). There were no significant differences forthe peak values of the other outcomes (ipsilateral trunk lean, contralateral pelvic drop, hip adduction, knee abduction, rear-foot eversion and hip internal rotation). The PFP group, however, presented with larger group means for all the outcomes in comparison with the control group.Conclusion: Peak knee external rotation was significantly increased in individuals with PFP compared to controls during the SLS. The findings of this study highlight the usefulness of the SLS as a testfor altered kinematics in individuals with PFP. Future studies may explore possible contributing factors to excessive knee external rotation, such as trunk and lower limb muscle imbalances.Further studies are needed to evaluate the kinematic differences between individuals with unilateral and bilateral PFP.

[发布机构] Stellenbosch University