Compensatory gait strategies for reduced ankle work in patients with unilateral flaccid calf muscle weakness

Impaired calf muscle strength in patients with neuromuscular diseases typically reduces ankle work during push-off, leading to increased energy dissipation (i.e. negative work) at contralateral heel-strike [1]. To overcome the reduced push-off work and consequent energy dissipation, patients have to compensate by producing more positive work elsewhere to maintain their walking speed. Increments in positive hip work in the affected leg and positive total work in the non-affected leg have been proposed as possible compensation strategies in patients with spastic calf muscle weakness [2] and in below knee amputees [3].
However, knowledge about which compensations are used in neuromuscular disease patients exhibiting flaccid calf muscle weakness is currently lacking, and may be useful to inform treatment decisions, including the specs of orthotic devices.