Armstrong’s proposed model of Delayed Onset Muscle Soreness
1. High tension in muscle during eccentric muscle contraction results in structural damage to the muscle and its cell membrane. An eccentric contraction is the lengthening of muscle and happens when you are decending into a squat or lowering yourself down from a rope climb.
2. Cell membrane damage disturbs calcium homeostasis in the injured fiber, resulting in necrosis (death of cell) that peaks ~48 h post exercise. (Calcium is needed for a muscle contration to occur)
3. Products of macrophage activity and intracellular contents (i.e., histamines, kinins and K+) accumulate outside the cell and stimulate free nerve endings in the muscle.
