Constant Resistance During Proportional Speed Provoked Higher Lower Limb Proximal Musculature Recruitment than Distal Musculature in Young Healthy Adults

Abstract
The lack of exercise in society today often leads to severe muscle loss and poor physical performance. Training methods targeting specific weakened muscle groups can help prevent or counteract muscle loss. This study aimed to analyze how the lower extremity muscles are activated when pushing a sled with constant resistance at two different speeds. Twenty-six participants with an average age of 23.77 years consented to having electromyography surface electrodes placed along the gluteus maximus (GMax), gluteus medius (GMed), tibialis anterior (TA), and gastrocnemius (GA) of their dominant leg. Muscle activation levels were then measured while the participant walked and ran with and without sled resistance. The study results showed that muscle activation was comparable during all trials and was not influenced by speed or constant resistance. However, the muscle activation for GMax and GMed was significantly higher than the activation levels exhibited by GA and TA. While pushing a sled has been shown to impact all studied musculature similarly, adding resistance to the movement can affect gait parameters such as stride length and cadence. Our findings support the use of sled training in patients with hip pathologies who are seeking to strengthen their GMax and GMed.