An evaluation of the heel strike transient in obese young adults during walking gait.

BACKGROUND

Obesity is considered a risk factor for knee osteoarthritis (OA) in part due to its influence on gait biomechanics. The heel strike transient (HST) is a characteristic of the ground reaction force that is indicative of a high rate of loading, but has not been evaluated in obese adults.

OBJECTIVE

To compare the incidence of HST in obese compared to normal weight adults.

METHODS

15 normal-weight (males=7, age=20.4±2.1years, body mass index=21.6±1.3kg/m(2)) and 15 obese (males=7, age=21.2±1.9years, body mass index=33.5±4.3kg/m(2)) young adults completed 10 walking trials at a standardized speed and 10 trials at a self-selected speed while ground reaction force data were sampled. HST incidence was evaluated using a dichotomous method previously identified in the literature, and compared between groups using χ(2) analyses.

RESULTS

The number of individuals classified as possessing the HST differed between the obese and normal-weight groups (8/15 vs. 3/15, p=0.047). Evaluation of the standardized residuals indicated a significantly greater than expected incidence of the HST in the obese group when walking at a standardized speed.

CONCLUSION

Our findings indicate that a greater proportion of obese compared to normal weight participants displayed a HST. The HST may provide a dichotomous method for identifying individuals with aberrant gait biomechanics.