In a previous study, muscle pain developed in the intact leg from 1 to 4 days after eccentric contraction
, but when a [BKB.sub.2] receptor antagonist was administered before eccentric contraction
, later muscle pain was suppressed, whereas the [BKB.sub.1] receptor antagonist exerted no muscle pain-inhibitory effects .
 In spite of an old concept, emphasis on the eccentric contraction
of large muscle groups as in downhill treadmill walk could emerge as a new or updated exercise modality.
The hip extensors are shown in Figure 4 (hip) as a sequence of the antagonist (eccentric contraction
) and agonist (concentric contraction) that performed negative and positive works, respectively, for the hip movements.
Although possible in insolated muscle preparations , eccentric contractions
are difficult to elicit and control through stimulation in clinical situations .
Research has shown that after severe eccentric contractions
that are followed by muscle soreness, muscle fibrils, connective tissues around fibers, the plasma membrane of muscle fibrils, sarcomeres, sarcoplasmic reticulum, or a combination of these parts are damaged, leading to special biochemical and functional symptoms in the individual .
may also stimulate tendon cells to produce collagen and decrease neovascularization that contributes to pain.
Rupture of the distal biceps tendon is a relatively rare injury that occurs when there is an unexpected, forceful eccentric contraction
of the biceps muscle.
* Eccentric contraction
utilizes extensibility and occurs as the muscle lengthens.
Selective damage of fast glycolytic muscle fibres with eccentric contraction
of the rabbit tibialis anterior.
It is slowly releasing tension, which is termed eccentric contraction
. For knee flexion, the quadriceps muscles are antagonist muscles that are in eccentric contraction
Various cytokines that act as inflammatory mediators that increase vascular permeability are produced in the damaged muscle within several hours after repeated eccentric contraction
(Paulsen et al., 2005; Peake et al., 2005).
In general, eccentric contraction
was induced by a higher ground impact force compared with that in concentric contraction.