In incomplete SCI, spinal stimulation commonly targets which muscle groups?

• A. Hip flexors and ankle extensors
• B. Finger flexors and wrist extensors
• C. Abdominals and intercostals
• D. Quadriceps and hamstrings

Answer: (A)

Spinal stimulation aims to re-engage the leg motor networks that drive stepping by boosting excitability of the muscles most essential for initiating and propelling a step. Hip flexors are key for lifting the leg and bringing it forward during the swing phase, while ankle extensors (the plantarflexors) provide the push-off and stable propulsion needed in stance. Together, these groups support the core actions of a stepping pattern and respond well to stimulation in incomplete SCI, especially when paired with rehabilitation to refine voluntary control.

Finger flexors and wrist extensors are used for hand function, not gait. Abdominals and intercostals help with trunk stability but don’t directly generate the leg movements needed for stepping. Quadriceps and hamstrings are important for knee control, but the combination of hip flexors and ankle extensors more consistently supports the rhythmic, coordinated leg movements involved in locomotion during stimulation-assisted rehab.