Q-angle in patellofemoral pain: relationship with dynamic knee valgus, hip abductor torque, pain and function.

OBJECTIVE: To investigate the relationship between the q-angle and anterior knee pain severity, functional capacity, dynamic knee valgus and hip abductor torque in women with patellofemoral pain syndrome (PFPS). METHODS: This study included 22 women with PFPS. The q-angle was assessed using goniometry: the participants were positioned in dorsal decubitus with the knee and hip extended, and the hip and foot in neutral rotation. Anterior knee pain severity was assessed using a visual analog scale, and functional capacity was assessed using the anterior knee pain scale. Dynamic valgus was evaluated using the frontal plane projection angle (FPPA) of the knee, which was recorded using a digital camera during step down, and hip abductor peak torque was recorded using a handheld dynamometer. RESULTS: The q-angle did not present any significant correlation with severity of knee pain (r = -0.29; p = 0.19), functional capacity (r = -0.08; p = 0.72), FPPA (r = -0.28; p = 0.19) or isometric peak torque of the abductor muscles (r = -0.21; p = 0.35). CONCLUSION: The q-angle did not present any relationship with pain intensity, functional capacity, FPPA, or hip abductor peak torque in the patients with PFPS.

OBJETIVO: Investigar a relação entre o ângulo-q e intensidade da dor anterior no joelho, capacidade funcional, valgo dinâmico de joelho e torque abdutor do quadril em mulheres com síndrome da dor patelofemoral (SDPF). MÉTODOS: Participaram do estudo 22 mulheres com SDPF. O ângulo-q foi avaliado pela goniometria, as participantes foram posicionadas em decúbito dorsal com joelho e quadril estendido e quadril e pé em rotação neutra. A intensidade da dor anterior do joelho foi avaliada pela escala visual analógica de dor e a capacidade funcional com a escala de dor anterior no joelho. O valgo dinâmico foi avaliado pelo ângulo de projeção no plano frontal do joelho (APPF), registrado com câmera digital durante step down, e o pico de torque dos abdutores do quadril com dinamômetro manual. RESULTADOS: O ângulo-q não apresentou correlação significativa com a intensidade da dor no joelho (r = −0,29; p = 0,19), capacidade funcional (r = −0,08; p = 0,72), ângulo de projeção no plano frontal do joelho (r = −0,28; p = 0,19) e pico de torque isométrico dos músculos abdutores (r = −0,21; p = 0,35). CONCLUSÃO: O ângulo-q não apresentou relação com a intensidade da dor, capacidade funcional, ângulo de projeção no plano frontal do joelho e pico de torque dos abdutores do quadril em pacientes com SDPF.

Q-angle in patellofemoral pain: relationship with dynamic knee valgus, hip abductor torque, pain and function / Ângulo-q na dor patelofemoral: relação com valgo dinâmico de joelho, torque abdutor do quadril, dor e função

OBJECTIVE: To investigate the relationship between the q-angle and anterior knee pain severity, functional capacity, dynamic knee valgus and hip abductor torque in women with patellofemoral pain syndrome (PFPS). METHODS: This study included 22 women with PFPS. The q-angle was assessed using goniometry: the participants were positioned in dorsal decubitus with the knee and hip extended, and the hip and foot in neutral rotation. Anterior knee pain severity was assessed using a visual analog scale, and functional capacity was assessed using the anterior knee pain scale. Dynamic valgus was evaluated using the frontal plane projection angle (FPPA) of the knee, which was recorded using a digital camera during step down, and hip abductor peak torque was recorded using a handheld dynamometer. RESULTS: The q-angle did not present any significant correlation with severity of knee pain (r = -0.29; p = 0.19), functional capacity (r = -0.08; p = 0.72), FPPA (r = -0.28; p = 0.19) or isometric peak torque of the abductor muscles (r = -0.21; p = 0.35). CONCLUSION: The q-angle did not present any relationship with pain intensity, functional capacity, FPPA, or hip abductor peak torque in the patients with PFPS.

OBJETIVO: Investigar a relação entre o ângulo-q e intensidade da dor anterior no joelho, capacidade funcional, valgo dinâmico de joelho e torque abdutor do quadril em mulheres com síndrome da dor patelofemoral (SDPF). MÉTODOS: Participaram do estudo 22 mulheres com SDPF. O ângulo-q foi avaliado pela goniometria, as participantes foram posicionadas em decúbito dorsal com joelho e quadril estendido e quadril e pé em rotação neutra. A intensidade da dor anterior do joelho foi avaliada pela escala visual analógica de dor e a capacidade funcional com a escala de dor anterior no joelho. O valgo dinâmico foi avaliado pelo ângulo de projeção no plano frontal do joelho (APPF), registrado com câmera digital durante step down, e o pico de torque dos abdutores do quadril com dinamômetro manual. RESULTADOS: O ângulo-q não apresentou correlação significativa com a intensidade da dor no joelho (r = -0,29; p = 0,19), capacidade funcional (r = -0,08; p = 0,72), ângulo de projeção no plano frontal do joelho (r = -0,28; p = 0,19) e pico de torque isométrico dos músculos abdutores (r = -0,21; p = 0,35). CONCLUSÃO: O ângulo-q não apresentou relação com a intensidade da dor, capacidade funcional, ângulo de projeção no plano frontal do joelho e pico de torque dos abdutores do quadril em pacientes com SDPF.

Relationship between frontal plane projection angle of the knee and hip and trunk strength in women with and without patellofemoral pain.

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.