Background There is limited data available on maintenance of improvements seen after short-term rehabilitation interventions for chronic ankle instability (CAI).

Objective To track the patient-reported efficacy of a 4-week intervention [wobble board (WB) or resistance tubing (RT)] in decreasing symptoms of CAI at 6 months post-intervention (6PI) as compared to immediately post-intervention (IPI).

Design Randomised controlled trial.

Setting Athletic training laboratory.

Patients (or participants) Fourteen out of 21 participants (66.7%) responded to an electronic 6 month follow-up questionnaire (age = 19.6 ± 0.9 years, height = 1.63 ± 0.18 m, body mass = 70.5 ± 16.3 kg, 2 males, 12 females, 5 WB, 9 RT). All participants met criteria for chronic ankle instability at enrollment, including a history of ankle sprain, Cumberland Ankle Instability Tool ≤ 25, episodes of giving way ≥ 1 every 6 months).

Interventions Participants completed either resistance tubing (RT) or wobble board (WB) protocols, both 12 sessions over 4 weeks of progressive exercise. WB sessions consisted of five 40 s sets of clockwise and counter-clockwise rotations. RT sessions consisted of 30 concentric contractions against resistance tubing in each of 4 ankle directions.

Main outcome measurements Patient reported symptoms of “giving-way” pre-intervention and at 6PI, global rating of change (GRC) frequencies at IPI and 6PI, and re-sprains at 6PI are presented descriptively. Global rating of function (GRF) at IPI and 6PI was compared using a paired-samples t-test (α = 0.05).

Results GRC indicated that 71.4% of participants rated their condition as improved IPI, whereas only 50% of participants were improved at 6PI. All participants reported “giving-way” pre-intervention; only 57.1% reported “giving-way” at 6PI. Re-sprains occurred in 21.4% of participants. GRF was not significantly different at IPI versus 6PI (p = 0.75; IPI = 91.7 ± 6.3, 6PI = 92.3 ± 10.0).

Conclusions Simple 4-week interventions maintained some but not all improvements at 6PI. Importantly, at least 42.9% of participants would no longer meet the current study’s CAI inclusion criteria due to lack of “giving-way”.