Affiliations: [a] Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, University of São Paulo, São Paulo, Brazil | [b] Physical Therapy Department, Federal University of Ceará, Fortaleza, Brazil
Abstract: BACKGROUND: It is theorized that increased dynamic knee valgus
relates to decreased hip posterolateral muscle strength. OBJECTIVE: The aim here was to assess the relationship between the
frontal plane projection angle (FPPA) of the knee and hip and trunk muscle
strength in women with and without patellofemoral pain (PFP). METHODS: The sample comprised 43 women: Patellofemoral Pain Group
(PPG, n = 22) and Control Group (CG, n = 21). Muscle strength for hip
abduction, extension, external rotation and lateral core were measured using
a handheld dynamometer. The FPPA was recorded during step-down. RESULTS: The PPG showed a deficit for hip muscles torque and
increased FPPA (P < 0.05). Negative correlation of the FPPA-Peak was found in
the CG for the hip abductor (r = -0.31) and posterolateral complex (r = -0.32)
(P < 0.05). In the PPG, the FPPA-Peak showed a moderate negative correlation
to the torque of external rotators and posterolateral hip muscles, although
this correlation did not reach statistical significance. CONCLUSIONS: These findings suggest that women with patellofemoral
pain present greater dynamic knee valgus and hip muscle weakness. Abductor
and posterolateral hip muscles strength are associated with increased FPPA
only in the pain-free population.
