Quadriceps force production during straight leg raising at different hip positions with and without concomitant ankle dorsiflexion

Due to the significant prevalence of knee disorders and patellofemoral pain syndrome, as well as the importance of quadriceps strengthening in knee rehabilitation programs, it is necessary to specify the best method to activate and strengthen the quadriceps muscles. The current study aimed at comparing the maximum generated isometric force during an active straight-leg-raising (SLR) maneuver in a sitting position by changing the hip rotational position with and without the simultaneous contraction of the ankle dorsiflexor muscles. The current study was performed on 30 healthy males recruited with a non-random and available sampling method. The maximum generated force was measured during the SLR maneuver in six compound internal and external rotations and in a neutral position with and without ankle dorsiflexor contraction. The obtained generated force was analyzed using repeated measures ANOVA. The generated forces in the SLR with and without contracting the ankle dorsiflexors were significantly different (p = 0.001), and taking different positions of hip rotation led to significant changes in the generated force (p = 0.005). The adoption of external hip rotation with the contraction of ankle dorsiflexors during the SLR maneuver generated the most force. Based on the interaction of these conditions, the general recommendation is to perform the SLR exercise in an external hip rotation with the simultaneous contraction of the ankle dorsiflexors in subjects with quadriceps muscle weakness.