Isotonic
- The contraction of a muscle with movement against a natural resistance. Isotonic actually means 'same tension', which is not the case with a muscle that changes in length and natural biomechanics that produce a dynamic resistance curve. This misnomer has prompted authors to propose alternative terms, such as dynamic tension or dynamic contraction.
Isokinetic
- The contraction of a muscle against concomitant force at a constant speed. Diagnostic strength equipment implement isokinetic tension to more accurately measure strength at varying joint angles.
Concentric
- The contraction of a muscle resulting in its shortening.
Eccentric
- The contraction of a muscle during its lengthening.
Dynamic
- The contractions of a muscle resulting in movement. Concentric and eccentric contraction are considered dynamic movements.
Isometric
- The contraction of a muscle without significant movement, also referred to as static tension. Also see Isometric Training.