Functional performance deficits associated with ligamentous instability at the ankle

Objectives: To examine whether ankle anterior drawer ligament laxity is associated with deficits in performance testing among otherwise healthy sportspeople.

Design: Cross-sectional cohort study.

Methods: Eighty-six volunteers from among sports participants at a military academy consented to the use of their pre-participation musculoskeletal screening information for the lower limb, and to an additional test of ankle proprioception. The lower limb screening included tests of ankle ligament laxity, dorsiflexion range of movement, single leg hop-for-distance, hexagon agility hopping test, and hop-and-hold landing stability test.

Results: There was a significant difference between lax and stable ankles on the 4 screening tests when they were examined together with MANOVA (F=3.52, df=4, 167, p=0.009, Wilks' Lambda=0.92). Independent t-tests showed worse performance on the hop-for-distance (p=0.001), hexagon hop (p=0.039) and the proprioception tests (p=0.033) associated with laxity. Comparing stable and unstable ankles in the same individual, paired t-tests showed significantly lower hop counts for lax ankles on the hexagon hop test (p=<0.001).

Conclusions: Ankle ligament laxity is associated with persisting deficits in explosive power, agility and proprioception, as demonstrated by less hopping distance, fewer hops in hexagon hop testing, and reduced proprioceptive acuity, despite ongoing participation in sport. Attention to maximising sport-related performance in the late stages of rehabilitation is suggested as an essential addition to clinical management of these injuries.