Effects of 1 week of unilateral ankle immobilization on plantar-flexor strength, balance, and walking speed: a pilot study in asymptomatic volunteers.

CONTEXT: Ankle immobilisation is often used following ankle injury. OBJECTIVE: To determine the influence of one week's unilateral ankle immobilisation on plantarflexor strength, balance and walking gait in asymptomatic volunteers. DESIGN: Repeated measures laboratory study. SETTING: University laboratory. PARTICIPANTS: Six physically active male participants with no recent history of lower limb injury. INTERVENTIONS: Participants completed a one week period of ankle immobilisation achieved through wearing a below knee ankle cast. Before the cast was applied, as well as immediately following cast removal, at 24 hours after cast removal, and at 48 hours after cast removal, their plantarflexor strength was assessed isokinetically, and they completed a single leg balance task as a measure of proprioceptive function. An analysis of their walking gait was also completed MAIN OUTCOME MEASURES: Peak platarflexor torque and balance were used to determine any effect on muscle strength and proprioception following cast removal. Ranges of motion (3D) of the ankle, knee and hip, as well as walking speed were used to assess any influence on walking gait. RESULTS: Following cast removal, plantarflexor strength was reduced for the majority of participants (p=0.063, CI=-33.98-1.31) and balance performance was reduced in the immobilised limb (pCONCLUSIONS: The reduction in strength and balance after such a short period of immobilisation suggested compromised central and peripheral neural mechanisms. This suggestion appeared consistent with the delayed increase in walking speed which could occur as a result of the excitability of the neural pathways increasing towards baseline levels. Language: en