Evaluating skeletal muscle electromechanical delay with intramuscular pressure.

ABSTRACT

INTRODUCTION: Intramuscular pressure (IMP) is the fluid pressure generated within skeletal muscle and directly reflects individual muscle tension. The purpose of this study was to assess the development of force, IMP, and electromyography (EMG) in the tibialis anterior (TA) muscle during ramped isometric contractions and evaluate electromechanical delay (EMD). METHODS: Force, EMG, and IMP were simultaneously measured during ramped isometric contractions in eight young, healthy human subjects. The EMD between the onset of force and EMG activity (Δt-EMG force) and the onset of IMP and EMG activity (Δt EMG-IMP) were calculated. RESULTS: A statistically significant difference (p < 0.05) was found between the mean force-EMG EMD (36 ±â€¯31 ms) and the mean IMP-EMG EMD (3 ±â€¯21 ms). CONCLUSIONS: IMP reflects changes in muscle tension due to the contractile muscle elements.