Muscle System Terminology
The following definitions are used when referring to the muscular system:
Fixed (anchored) attachment of the muscle. The origin does not normally move during contraction.
Point of attachment of muscle opposite to origin. The insertion normally moves towards the origin when the muscle contracts.
The function of the muscle, i.e. what happens when the muscle contracts.
A condition where some muscle fibres are contracted and others are relaxed so that the muscle is 'semi-contracted'. This maintains posture of the body.
Over stimulus of a muscle so that more fibres are contracted than is necessary for the muscle to function.
Condition in which a skeletal muscle is frequently stimulated and is forced to contract faster than it can remove lactic acid (and deal with other metabolites). The muscle will not now be able to contract until it has been allowed to rest.
Bending of a joint, i.e. decreasing the angle across that joint.
Straightening of a joint, i.e. increasing the angle across that joint.
Movement occurring in the coronal plane, i.e. (sideways) away from the trunk or median, i.e. moving it away from the body.
Movement occurring in the coronal plane, i.e. (sideways) towards the trunk or median, i.e. adding it to the body.
Turning of a limb about its axis.
Movement of the flexed forearm so that the palm of the hand is turned anterior or superior.
Movement of the flexed forearm so that the palm of the hand is turned posterior or anterior.
Flexion of the ankle joint so that the angle between the shin and foot decreases, i.e. standing on heels.
Flexion of the ankle joint so that the angle between the shin and foot increases, i.e. standing on tip toes.