Effects of Functional Electrical Stimulation on Spasticity, Quadriceps Muscle Strength and Functional Mobility in Individuals With Paraplegia (FES-PAR-RCT)

Spinal cord injury (SCI) is a major cause of long-term disability worldwide, often resulting in paraplegia when the thoracic, lumbar, or sacral spinal segments are affected. Individuals with paraplegia commonly experience significant impairments in voluntary motor control, muscle weakness, spasticity, and reduced functional mobility, all of which contribute to decreased independence in activities of daily living.

Spasticity, defined as a velocity-dependent increase in muscle tone due to hyperexcitability of the stretch reflex, is one of the most frequent complications following upper motor neuron lesions. Although spasticity may occasionally contribute to functional stability, excessive spasticity often interferes with voluntary movement, gait training, and rehabilitation outcomes (Pandyan et al., 2005).

Functional Electrical Stimulation (FES) is a neurorehabilitation technique that delivers electrical impulses to peripheral nerves to evoke functional muscle contractions. It facilitates neuromuscular re-education, enhances motor unit recruitment, and may promote neuroplasticity in the central nervous system. Previous studies have demonstrated that FES can improve muscle strength, walking ability, and functional independence in individuals with neurological impairments (Sheffler & Chae, 2007; Kesar et al., 2010; Hesse et al., 2003).

This study is designed as a prospective, single-center, parallel-group, randomized controlled trial conducted in accordance with CONSORT 2010 guidelines. A total of 60 participants with paraplegia secondary to spinal cord injury will be enrolled and randomly allocated into two groups:

Control Group: Standard neurorehabilitation program only Intervention Group: Standard neurorehabilitation program + FES applied to the quadriceps femoris muscle The rehabilitation program will be conducted 3 days per week for 8 weeks and will include stretching exercises, strengthening exercises, balance training, and transfer training. In the intervention group, FES will be applied 5 days per week for 8 weeks with the following parameters: 35 Hz frequency, 300 µs pulse duration, and 10 seconds on / 20 seconds off cycle.

Outcome assessments will be performed at baseline (week 0) and after intervention (week 8). Spasticity will be evaluated using the Modified Ashworth Scale (MAS), which is widely used in clinical practice for assessing muscle tone in neurological conditions. Quadriceps muscle strength will be measured using Manual Muscle Testing (MMT) based on the Medical Research Council (MRC) scale. Functional mobility and independence will be assessed using SCIM, TUG, and 6MWT.

SCIM is a validated scale specifically developed for individuals with spinal cord injury and assesses self-care, respiration and sphincter management, and mobility domains. TUG test provides an objective measure of functional mobility and fall risk, while 6MWT evaluates functional exercise capacity and endurance.

The primary hypothesis of this study is that FES combined with conventional rehabilitation will significantly reduce spasticity, improve quadriceps muscle strength, and enhance functional mobility compared to conventional rehabilitation alone.

The results of this study are expected to contribute to the evidence base regarding the clinical effectiveness of FES in neurorehabilitation and may support its integration into standard rehabilitation protocols for individuals with paraplegia.