Evaluation of the neuromuscular compartments in the peroneus longus muscle through electrical stimulation and accelerometry

Abstract

| Background: Muscles are innervated exclusively by a nerve branch and possess definite actions. However, mammalian skeletal muscles, such as the trapezius, the medial gastrocnemius, and the peroneus longus, are compartmentalized. In the peroneus longus muscle, multiple motor points, which innervate individual neuromuscular compartments (NMC), the superior (S-NMC), anteroinferior (AI-NMC), and posteroinferior (PI-NMC), have been described. The contribution of each neuromuscular compartment to the final action of the muscle is fundamental for the rehabilitation of patients afflicted by neurological and muscle dysfunctions. Interventions are often based on electrical principles that take advantage of the physiological characteristics of muscles and nerves to generate therapeutic effects. Objective: To compare the effects of stimulating the different neuromuscular compartments (NMCs) of the peroneus longus muscle on the motor threshold (MT) and acceleration of the foot. Method: This is a cross-sectional study comprising 37 subjects. The three NMCs of the peroneus longus muscle were stimulated, and the acceleration of the foot and the motor threshold of each NMC were evaluated. A repeated measures analysis of variance with Bonferroni corrections of two intra-subjects factors was performed. Results: The stimulation of the different NMCs did not result in any differences in MT (F=2.635, P=0.079). There were significant differences between the axes of acceleration caused by the stimulation of the different NMCs (F=56,233; P=0.000). The stimulation of the posteroinferior compartment resulted in the greatest acceleration in the X-axis (mean 0.614; standard deviation 0.253). Conclusions: The posteroinferior compartment primarily contributes to the eversion movement of the foot. NMCs have specific functional roles that contribute to the actions of the muscles to which they belong.Keywords: neuromuscular compartment; peroneus longus muscle; accelerometry; motor threshold; motor point; physical therapy. HOW TO CITE THIS ARTICLEMéndez GA, Gatica VF, Guzmán EE, Soto AE. Evaluation of the neuromuscular compartments in the peroneus longus muscle through electrical stimulation and accelerometry. Braz J Phys Ther. 2013 Sept-Oct; 17(5):427-434. http://dx

Individuals with chronic ankle instability show altered regional activation of the peroneus longus muscle during ankle eversion

“…On the other hand, the No‐CAI group had greater sEMG amplitude in the posterior compartment than in the anterior compartment. A previous report supports this finding from a biomechanical point of view 17 . Electrical stimulation of the motor point of the posterior compartment of the peroneus longus causes higher acceleration in the medio‐lateral axis of the foot compared with the stimulation of the motor point of the anterior compartment, suggesting a greater contribution of the posterior compartment to the eversion movement 17 …”

“…A previous report supports this finding from a biomechanical point of view. 17 Electrical stimulation of the motor point of the posterior compartment of the peroneus longus causes higher acceleration in the medio-lateral axis of the foot compared with the stimulation of the motor point of the anterior compartment, suggesting a greater contribution of the posterior compartment to the eversion movement. 17 In other human muscles, differences in regional muscle activity have been observed.…”

“…17 Electrical stimulation of the motor point of the posterior compartment of the peroneus longus causes higher acceleration in the medio-lateral axis of the foot compared with the stimulation of the motor point of the anterior compartment, suggesting a greater contribution of the posterior compartment to the eversion movement. 17 In other human muscles, differences in regional muscle activity have been observed. 14,[38][39][40] For instance, a higher sEMG amplitude of the proximal region of the rectus femoris during hip flexion has been reported.…”

“…15 Specifically, during an eversion of the ankle, a greater activation of the anterior and posterior muscle compartments is observed, whereas during plantarflexion, a lower activation of the posterior compartment has been reported. This regional activation of the peroneus longus is related to its anatomical and biomechanical organization, [16][17][18] contributing mainly to eversion movement during motor tasks like walking, jumping, and running. Despite of these within-muscle variations in activity, some investigations using conventional bipolar single-channel methods have reported no differences in surface electromyographic (sEMG) amplitude of the peroneus longus between individuals with CAI and healthy controls.…”

Comparison of the Electromyographic Activity of Different Zones of the Abductor digiti minimi manus Muscle in Search of a Functional Compartmentalisation

“…Furthermore, Wickham & Brown (2012) showed the existence of a FC in the pectoralis major and latissimus dorsi muscles, in relation to different movements of the shoulder. Likewise, Méndez et al (2013) reported the existence of three functional compartments in the fibularis longus muscle.…”