During forward sway, which EMG pattern best describes the ankle strategy?

• A. Distal-to-proximal activation: gastrocnemius/soleus first, followed by hamstrings/quadriceps and paraspinals
• B. Proximal-to-distal activation: paraspinals first, then quadriceps
• C. Simultaneous activation of all major trunk muscles
• D. No muscle activation occurs during small sway

Answer: (A)

Ankle strategy in forward sway starts with distal-to-proximal muscle activation. When the body sways forward, the calf muscles (gastrocnemius and soleus) fire first to produce plantarflexion at the ankle, creating a corrective torque that pulls the body back toward upright. If needed, the response then includes more proximal muscles (hamstrings and paraspinals) to reinforce stability. This sequencing—calf muscles first, then thigh and trunk muscles—best matches a small, ankle-dominated perturbation.

The other patterns don’t fit because a proximal-to-distal sequence would indicate the hip strategy taking precedence early, which is more typical for larger sways. Simultaneous activation of all major trunk muscles isn’t the orderly, direction-specific response seen in the ankle strategy, and no muscle activation would fail to generate the necessary corrective torque.