Intramuscular pressure during walking: an experimental study using the wick catheter technique.

Experimental studies have shown previously that intramuscular pressure is directly related to muscle tension. A wick catheter study of intramuscular pressure in the human tibialis anterior was performed to investigate dynamic changes in walking and in other selected activities. In walking, peak intramuscular pressure of 50 mm Hg occurred in the swing phase as the foot was lifted and continued in early stance phase during deceleration of the foot. Passive stretching of the tibialis anterior muscle produced an increase to 35 mm Hg with no EMG activity. Active contraction against heavy resistance produced a rise in intramuscular pressure to 107 mm Hg. In contrast to electromyography, intramuscular pressure represents both the active and passive components of muscle tension.