Medicine & Science in Sports & Exercise:
A-43 Free Communication/Poster - Sports Equipment: JUNE 1, 2011 7:30 AM - 12:30 PM: ROOM: Hall B
Nakamura, Bryson H.; Orloff, Heidi A.; Field-Eaton, Sean D.; Olesh, Erienne V.
University of Puget Sound, Tacoma, WA.
(No relationships reported)
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.