Effects of Body Mass Index on Biomechanics of Adult Female Foot

Abstract

Background & Introduction: Adult obesity has been associated with a higher prevalence of musculoskeletal disorders, primarily affecting the lower limbs. Foot problems in obese adults are most important. Increased body weight is considered to cause overload of foot, which represents the interface between body and ground. Aims & Objectives: To study the effect of body weight on calcaneal eversion, angle of toe-out and gastrocnemius extensibility of adult female. Materials & Methods: Twenty female subjects at the age 20-30years were divided into 2 groups based on their Body Mass Index (BMI). Ten females with BMI 18.5-24.5 were assigned to Group A (Control) and rest ten were assigned to Group B (Overweight) having BMI between 25-29. A non- random convenient female sample was taken into the consideration. Subjects suffering from ligament injury, fracture, foot pain, limb length discrepancy were excluded from this study. Statistical analysis: Calcaneal eversion, gastrocnemius extensibility and angle of toe out in normal and overweight females were compared by applying unpaired t- test. P-value was set at 0.05 considered to be significant. Results & Discussion: The results showed no significant difference between the two groups in calcaneal eversion. Obesity can contribute to excessive pronation and foot pain. Gastrocnemius extensibility is less in overweight females (p<0.001). This is because of excessive pronation which causes shortening of tendo-Achilles and instability at subtalar and midtarsal joint. The Angle of toe-out was found to be greater in overweight females (p<0.001). Overweight females have significant greater rear foot motion and foot angle values than normal weight females. Calcaneal eversion is greater in overweight females but it was statistically insignificant whereas angle of toe out was greater in overweight females which were highly significant. Gastrocnemius extensibility was less in overweight females when compared with normal subjects. Conclusion: We concluded that a high BMI could influence foot characteristics which may therefore predispose individuals to musculoskeletal pain.