Facilitating activation of the peroneus longus: electromyographic analysis of exercises consistent with biomechanical function.

Exercises for the ankle are often used to improve sport performance through balance and stability or to prevent or recover from ankle injury. Ankle training programs often include exercises for the primary muscle of the lateral ankle, the peroneus longus (PL). However, many exercises for the PL are non-weight bearing and unidirectional. However, data from biomechanical studies show that peak activity of the PL occurs neither in non-weight-bearing nor during uniplanar movements. This lack of congruency may limit the effectiveness of PL training. Exercises more consistent with the biomechanical function of the PL may increase the efficacy of ankle training. This study examined and compared the electromyographic (EMG) activity of the PL during 2 exercises that specifically address the known biomechanical function of the PL and a traditional non-weight-bearing unidirectional PL exercise. Twenty healthy college-aged men and women (age 24.8 +/- 2.7 years) without history of ankle injury were examined in a single-session repeated measures design. The average root means square (RMS) values of the PL during each of the 3 exercises were measured and compared to assess for differences in magnitude of muscular activity. The RMS activity of the PL was significantly greater (p < 0.05) in each of the biomechanically correct exercises when compared with the conventional exercise. However, no significant difference was noted in EMG activity between the 2 biomechanical exercises. This study provides evidence for increased activity from the PL during 2 exercises that more accurately reflect its biomechanical function. Use of these exercises when training the PL for sports performance or rehabilitation may increase the effectiveness of ankle training programs that include PL activity.