The Influence Of Weight-bearing Lower Extremities Rotational Resistance Exercises On Range Of Motion

Hip range of motion (ROM) is essential in Activities of Daily Living (ADL), fitness, and performance. Decreased hip ROM has been associated with higher risk of hip and knee injuries. Decreased hip internal rotation (IR) and external rotation (ER) have been identified as injury risk factors and may decrease performance. Weight-bearing stretching techniques for hip flexors and extensors muscles shown to increase hip ROM, which has been associated with increased performance and decreased prevalence of injury. Little is known about the effects of weight-bearing stretching on lower extremities (LE) IR and ER ROM. PURPOSE: Investigate the effect of weight-bearing LE rotational resistance exercises on IR and ER ROM. METHODS: Thirteen healthy adults participated (21.5 ± 2.2 yrs; 66.8 ± 19.8 kg, 157.2 ± 28.1 cm). Pre- and Post-intervention LE IR and ER ROM were measured in a standing position using a weight-bearing rotational device. Participants IR and ER ROM were measured in four different hip positions: flexion IR (FIR) and ER (FER), extension IR (EIR) and ER (EER), adduction IR (ADIR) and ER (ADER), abduction IR (ABIR) and ER (ABER). Tests order was randomized. Three consecutive IR and ER ROM measurements were taken for each hip position; the highest score was recorded, and the ARC (IR + ER) was calculated. Participants partook in an intervention for three weeks, three times a week, of four pre-loading dynamic resistance exercises on the device. A paired t-test was used to compare pre-and post-intervention results. The significance level was set at p = 0.05. RESULTS: Post intervention results were significantly higher than pre for the following measurements; in flexion p = 0.029 (16.9 ± 37.1), abduction p = 0.010 (16.5 ± 30.2), and adduction p = 0. 025 (17.4 ± 37.2). No significant difference was found in extension p = 0.063 (14 ± 36.8). Same pattern was seen in IR and ER; in FER p = 0.013 (10.7 ± 20.4), ABIR p = 0.022 (8.1 ± 16.9), ABER p = 0.029 (8.3 ± 18.3), and ADER p = 0.019 (10.1 ± 20.6). No statistical significance was found in FIR p = 0.10 (6.7 ± 20.4), EIR p = 0.15 (5.7 ± 19.7), EER p = 0.092 (8.3 ± 24.2), and ADIR p = 0.091 (7.2 ± 20.9). CONCLUSION: Weight-bearing resistance rotational exercises program showed an improvement in ROM. It may be valuable information to implement when designing exercise interventions for various populations.