Muscle-activation onset times with shoes and foot orthoses in participants with chronic ankle instability

CONTEXT: Participants with chronic ankle instability (CAI) use an altered neuromuscular strategy to shift weight from double-legged to single-legged stance. Shoes and foot orthoses may influence these muscle-activation patterns. OBJECTIVE: To evaluate the influence of shoes and foot orthoses on onset times of lower extremity muscle activity in participants with CAI during the transition from double-legged to single-legged stance. DESIGN: Cross-sectional study. SETTING: Musculoskeletal laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 15 people (9 men, 6 women; age = 21.8 ± 3.0 years, height = 177.7 ± 9.6 cm, mass = 72.0 ± 14.6 kg) who had CAI and wore foot orthoses were recruited. INTERVENTION(S): A transition task from double-legged to single-legged stance was performed with eyes open and with eyes closed. Both limbs were tested in 4 experimental conditions: (1) barefoot (BF), (2) shoes only, (3) shoes with standard foot orthoses, and (4) shoes with custom foot orthoses (SCFO). MAIN OUTCOME MEASURE(S): The onset of activity of 9 lower extremity muscles was recorded using surface electromyography and a single force plate. RESULTS: Based on a full-factorial (condition, region, limb, vision) linear model for repeated measures, we found a condition effect (F(3,91.8) = 9.39, P < .001). Differences among experimental conditions did not depend on limb or vision condition. Based on a 2-way (condition, muscle) linear model within each region (ankle, knee, hip), earlier muscle-activation onset times were observed in the SCFO than in the BF condition for the peroneus longus (P < .001), tibialis anterior (P = .003), vastus medialis obliquus (P = .04), and vastus lateralis (P = .005). Furthermore, the peroneus longus was activated earlier in the shoes-only (P = .02) and shoes-with-standard-foot-orthoses (P = .03) conditions than in the BF condition. No differences were observed for the hip muscles. CONCLUSIONS: Earlier onset of muscle activity was most apparent in the SCFO condition for ankle and knee muscles but not for hip muscles during the transition from double-legged to single-legged stance. These findings might help clinicians understand how shoes and foot orthoses can influence neuromuscular control in participants with CAI.

Jaar van publicatie:2015

BOF-keylabel:ja

IOF-keylabel:ja

BOF-publication weight:2

CSS-citation score:1

Authors from:Higher Education

Toegankelijkheid:Closed