Foot Function in Lateral Ankle Sprains and Chronic Ankle Instability

Purpose: To compare three-dimensional multisegmented ankle-foot kinematic and clinical measures of foot posture and morphology, multisegmented joint motion and play, strength, and dynamic balance in in acute ankle sprain (LAS), chronic ankle instability (CAI), coper, and control groups. The effects of midfoot joint mobilizations and a one-week home exercise program (HEP) compared to a sham intervention and HEP on clinical measures were also studied in the LAS group.
Methods: A cross-sectional study of 80 recreationally-active individuals (Control: n=22, Coper: n=21, LAS: n=17, CAI: n=20) assessing group differences in sagittal, frontal, and transverse plane kinematics of the hallux, medial forefoot, lateral forefoot, medial midfoot, lateral midfoot, and rearfoot on shank during the stance phase of gait during barefoot walking using an electromagnetic motion capture. Clinical measures foot posture index (FPI), morphologic measures, joint motion and play at the rearfoot and forefoot, strength of the ankle and hallux, and Star Excursion Balance Test (SEBT) were also assessed.
A laboratory-based, crossover randomized control trial was performed in participants with a recent LAS. All participants were instructed in a stretching, strengthening, and balance HEP and were randomized a priori to receive midfoot joint mobilizations (forefoot supination cuboid glide and plantar 1st tarsometatarsal) or a sham laying-of-hands. Changes in pain, physical, psychological, and functional PROs, foot morphology, joint mobility, tissue reactivity, sensorimotor function, and dynamic balance were assessed pre-to-post treatment and one-week following. Participants crossed-over following a one-week washout to receive the contrast treatment and were assessed pre, post, and one-week following.
Results: The LAS group had up to 4.1° more rearfoot inversion during midstance of gait (mean difference: 3.1°) from 42 to 49% of stance phase compared to healthy controls. The CAI group had up to 5.3° more rearfoot inversion (mean difference: 3.6°) from 34% to 91% of stance phase compared to controls. There were no further statistical differences found between CAI and Copers, other planes, or segments of the ankle foot complex. There were no significant group differences in FPI or morphological measures. Compared to controls, LAS and CAI groups had decreased ankle dorsiflexion and greater forefoot and rearfoot frontal plane motion, increased 1st MT plantarflexion and sagittal excursion, increased talocrural glide and internal rotation, decreased forefoot inversion joint play, and decreased strength in all motions except dorsiflexion. The LAS group also demonstrated decreased distal tibiofibular and forefoot general laxity, and SEBT performance compared to controls.
Midfoot joint mobilization had greater effects in reducing pain 1-week post, and increasing Single Assessment Numeric Evaluation, Global Rating of Change, forefoot inversion, and plantar tarsometatarsal joint play compared to a sham treatment and HEP following LAS.
Conclusion: Groups with LAS and CAI demonstrate more rearfoot inversion and altered joint function and strength in the multisegmented ankle-foot complex compared to controls. Clinicians and researchers should include interventions that control inversion and increase eversion following LAS or CAI. Midfoot joint mobilizations and HEP yielded greater pain reduction, perceived improvement, and forefoot joint play compared to sham.