| Falls are the third leading cause of unintentional death in homes and communities in the United States, causing 27,800 fatalities in 2012. The ability to maintain postural control is an essential part of activities of daily living (ADLs). However, recent types of casual footwear may be putting the body's postural control system at a functional disadvantage, predisposing wearers to the risk of a fall. The purpose of this study was to examine the effects three forms of casual footwear (thong style flip-flops (FF), clog style CrocsRTM (CC), and VibramRTM Five-Fingers (MIN)) have on postural control following a one mile walk at a preferred-pace. Eighteen healthy male adults (age: 22.9+/-2.8 years; height: 179+/-6.0 cm; mass: 81.3+/-8.8 kg) with no history of neuro-musculoskeletal disorders participated in this study. Static balance measures were recorded using eyes open (EO), eyes closed (EC), eyes open with sway referenced vision (EOSRV), and support, (EOSRP) conditions of the Sensory Organization Test (SOT). The average velocity (VEL) and root-mean-square (RMS) of the center of pressure (CoP) was used to quantify postural sway in the anterior-posterior (APVEL & APRMS) and medial-lateral (MLVEL & MLRMS) directions. Dynamic balance measures were recorded using the medium and large translations of the Motor Control Test (MCT). Muscle activity was collected at 1,500 Hz on the medial gastrocnemius (PF) and tibialis anterior (DF) using a Noraxon EMG system. Mean sway and EMG variables were analyzed using a 3x2 (footwear x time) repeated measures ANOVA. Footwear main effect significance was observed for APRMS in the EC condition (F2,34) = 7.914, p = 0.002), MLVEL (F(2,34) = 3.681, p = 0.036), and APVEL (F(2,34) = 7.469, p = 0.002) in the EOSRV condition with pairwise comparisons displaying increased instability in the CC and FF compared to MIN. Time main effect significance was seen for MLRMS in the EOSRV (F(1,17) = 6.532, p = 0.02) and EOSRP (F(1,17) = 8.982, p = 0.008) conditions with increased instability following the one-mile walk. Future research should seek to elucidate which combinations of these casual footwear characteristics are most detrimental to human balance. |
