Effect of Leg Length on Physiological Cost Index in Young Adults

Background and need of research: By Physiological Cost Index we estimate the energy cost in walking of healthy people, also it has been reported for persons with different leg length that requires the energy consumption. The Physiological Cost Index (PCI) method requires simply recording of HR at rest and while walking. We undertook this study aiming to present the energy consumption in subjects having different leg length. Method: A cross sectional study was conducted in 50 individuals of age group 18-25 (young adults) years and normal BMI category according to Asian BMI classification (18.5-22.9Kg/m2). Resting HR Leg length was measured. The subject walked 1 km on treadmill for 6.5km/h speed and walking HR was measured and the physiological cost index was calculated. Data was analyzed using SPSS 20. Result: Mean age and BMI of participants were (21.66 ± 1.5) and (21.08 ± 1.1) respectively. By using Pearson’s test, there is highly statistically significant negative correlation (r= -0.600, P<0.05) between Leg length and PCI. As leg length (80.88 ± 6.85) increases, PCI (0.83 ± 0.11) value decreases. Conclusion and clinical implication: The present study concluded that individuals with shorter height experiences more energy expenditure. This correlation indicates that there is a relationship between leg length and stride length frequency, which in turn effects on speed and efficiency of walking. Keywords: Physiological cost index, Leg length, energy expenditure, treadmill walking