Lumbo-Pelvic-Hip Complex Endurance and Diaphragm Contractility in Females with Patellofemoral Pain Syndrome: A Case-Control Study

Abstract

Background: The diaphragm muscle constitutes the internal component of the Lumbo-Pelvic-Hip Complex (LPHC), and its stability is suggested to influence lower limb joint function, particularly the alignment of the patellofemoral joint and the tracking path mechanism of the patella. Objectives: To compare the endurance of the LPHC and diaphragm contractility in females with patellofemoral pain syndrome (PFPS) and a healthy control group. Methods: Fifty-six females, including twenty-eight diagnosed with patellofemoral pain syndrome and twenty-eight healthy females matched as controls (aged 15 - 45), were invited to participate in this case-control study. Endurance scores of trunk extensor, flexor, and lateral flexor muscles, endurance ratios, and the percentage of diaphragm muscle contractility using the ultrasonography method were compared between the two groups. Results: The endurance time of trunk flexors and right and left lateral muscle groups in the PFPS group significantly differed compared to the control group (P < 0.05). Diaphragm contractility in both the right (Mean ± SD: 21.82 ± 3.61; P < 0.001) and left (Mean ± SD: 22.92 ± 2.99; P = 0.007) sides was significantly lower in the PFPS group compared to the control group. Conclusions: Lumbo-Pelvic-Hip Complex stability and diaphragm respiratory function and contractility were impaired in females with PFPS.