A-43 Free Communication/Poster - Sports Equipment: JUNE 1, 2011 7:30 AM - 12:30 PM: ROOM: Hall B
It has been found that changes in the construction, texture or stiffness in the sole of shoes can change the gait of an individual (Nurse et al., 2005; Grey et al., 2004; Robbins & Gouw, 1990). The effect of instability in shoes has been shown to increase electromyographic (EMG) stimulation and strengthen kinematic and kinetic characteristics in the lower extremities (Nigg, Hintzen & Ferber, 2006). Thus it has been shown that shoe-heel materials alter muscle activation loading rate dependent on muscle impact forces (Nigg & Wakeling, 2001), as do the ground reaction forces (GRF) with motion control shoes (Cheung & Ng, 2008).
PURPOSE: To determine if different toning shoes increased muscular stimulation or GRFs during walking gait.
METHODS: Nineteen apparently healthy female subjects (34.14±17.26 years; 61.82±10.92 kg) participated in this study. EMG data of the gastrocnemius lateralis, tibialis anterior, rectus femoris, biceps femoris and gluteus maximus and GRFs were obtained for a control shoe (Shoe A) and two toning shoes (Shoes B & C). A one way analysis of variance (α < 0.10) was used to compare ARV, mean frequency and GRFs between the three conditions.
RESULTS: In Shoe B, the ARV of the gastrocnemius lateralis increased(0.0604 mV) compared to Shoes A (0.0503 mV) and C (0.0493 mV), while activity in the gluteus maximus decreased for toning Shoe B (18.52 Hz) compared to Shoes A (22.33 Hz) and C (21.82 Hz). GRFs revealed Shoe B to have higher mid-stance and lower toe-off forces, while Shoe C had a higher heel-strike force. Shoe B resulted in a significantly higher mid-stance force (0.74 BWU) and a significantly lower toe-off (1.03 BWU) compared to Shoes A (0.72 BWU, 1.09 BWU) and C (0.68 BWU, 1.08 BWU). Shoe C revealed a significantly higher heel-strike force (1.17 BWU) compared to Shoes A (1.12 BWU) and B (1.14 BWU). Shoe B (-0.22 BWU) and C (-0.21 BWU) resulted in significantly greater anterior forces compared to Shoe A (-0.19 BWU), while Shoe C (0.23 BWU) showed significantly higher posterior force than both Shoes A (0.21 BWU) and B (0.21 BWU).
CONCLUSIONS: Increased muscular stimulation created by toning shoes appearred to be limited to the gastrocnemius lateralis, while GRFs revealed changes in gait patterns when subjects wore toning shoes.