Anatomical Study of the Fibularis Longus Muscle Motor Points and Electrical Stimulation Therapy Application

Abstract

SUMMARY:The fibularis longus muscle (FLM) has an important role in the movement of eversion of the foot and in maintaining the plantar arch. The electrostimulation procedures seek to maintain muscle trophism, increase strength and endurance, and are frequently used in physiotherapy, for which the clinician needs to know the location of the motor points of the FLM. Therefore, the purpose of this study was to determine the number and distribution of motor points of the FLM and relate them to observable parameters in the surface anatomy. Ten formalin-preserved limbs were used, and the lateral regions of the leg were dissected in detail. In all the cases, the muscle presented three fascicular patterns, the superior and anteroinferior fascicles presented two motor points each, while the posteroinferior fascicles were between 2 and 3 motor points. Our results suggest that there is a pattern of distribution of the superficial fibular nerve, whose knowledge is useful for clinical application in the FLM electrostimulation proceedings.

Contribution of the peroneus longus neuromuscular compartments to eversion and plantarflexion of the ankle

“…Several investigations indicate that peroneus longus NMCs have a longitudinal topographic distribution respecting a muscular bipennate conformation, each one with one or two motor points distributed within the proximal third of the muscle [ 6 , 7 , 35 ]. From this point of view, it is possible to estimate that the location of the center of the electrode grid is within the proximal third and covering the anterior and posterior compartments.…”

“…Compartmentalization of animal and human skeletal muscles by multiple motor nerve branches, known as the neuromuscular compartment (NMC), has been observed primarily in muscles that participate in a plane of motion [ 1 – 3 ]. These compartments present a spatial distribution depending on the motor task [ 2 – 5 ] and have been investigated through anatomical-cadaveric [ 6 , 7 ], physiological-electromyographic [ 3 , 4 , 8 , 9 ], and biomechanical studies [ 5 , 9 – 11 ] in the trapezius [ 12 ], extensor digitorum communis [ 13 ], rectus femoris [ 3 , 9 , 11 ], hamstring [ 14 ], medial gastrocnemius [ 15 ], and masseter muscles [ 4 ], among others. Previous reports demonstrated region-specific activation properties of bi-articular muscles by using multi-channel surface electromyography (sEMG) [ 3 , 14 ].…”

“…However, there are few reports on neuromuscular compartmentalization in muscles that participate in two or more planes of movement. In this context, the peroneus longus muscle presents a compartmental subdivision from an anatomical and biomechanical point of view [ 5 – 7 ], and this muscle contributes to eversion and plantarflexion during motor tasks like walking and running on inclined planes [ 16 – 18 ].…”

“…The peroneus longus has a muscle belly with an average length of 12.4 ± 1.91 cm [ 19 ] and a compartmental anatomical organization [ 6 , 7 , 20 ]. This architectural subdivision has been reported in anatomical studies where four compartments have been observed, two deep and two superficial, organized around a central connective tissue with a longitudinal axis [ 6 ].…”

“…This architectural subdivision has been reported in anatomical studies where four compartments have been observed, two deep and two superficial, organized around a central connective tissue with a longitudinal axis [ 6 ]. The superficial compartments are called anterior and posterior, and they can be separately recorded by sEMG [ 6 , 7 ]. These characteristics have allowed the recording of its electrical activity through multi-channel sEMG using a 4 x 3 electrode grid and a 20 mm interelectrode distance [ 21 ].…”