Open and closed Chain Exercises

Open-Chain Exercises

Open-chain exercises involve motions in which the distal segment (hand or foot) is free to move in space, without necessarily causing simultaneous motions at adjacent joints.

 Limb movement only occurs distal to the moving joint. 
Muscle activation occurs in the muscles that cross the moving joint.
 For example,
 during knee flexion in an open-chain exercise  the action of the hamstrings is independent of recruitment of other hip or ankle musculature.

Open-chain exercises also are typically performed in non-weight-bearing position. In addition, during resistance training, the exercise load(resistance) is applied to the moving distal segment.

Closed-Chain Exercises

Closed-chain exercises involve motions in which the body moves on a distal segment that is fixed or stabilized  on a support surface.

Movement at one joint causes simultaneous motions at distal as well as proximal joints in a relatively predictable manner

. For example, when a patient is performing a bilateral short-arc squatting motion (mini-squat)  and then returning to an erect position,

 as the knees flex and extend,

the in the upper and lower extremities hips and ankles move in a predictable pattern along with the knees.