Change in triceps muscle intracompartmental pressure with repositioning and padding of the lowermost thoracic limb of the horse.

Triceps intracompartmental pressure was measured in the lowermost limb of the recumbent horse during the initial period of recumbency during elective surgical procedures in 11 horses. Intramuscular pressure, using an IM catheter, was measured with the thoracic limbs in 4 different positions, including (I) table-contact limb unadvanced-unsupported free limb, (II) table-contact limb unadvanced-supported free limb, (III) table-contact limb advanced cranially, unsupported free limb, and (IV) table-contact limb advanced cranially, supported free limb. Pressure was measured in the 4 positions with and without padding. The highest pressure was measured in position I without padding. The lowest pressure was measured with position IV with padding and was significantly lower than all pressures in other positions (P less than 0.05). Foam mattress padding significantly decreased muscle pressure in each position.