Open and Closed Kinetic Chain in Physical Therapy

In rehab settings such as sports and physical therapy clinics, the body is often viewed as a series of linked parts. It's like that old song "Dem Bones," where "the hip bone is connected to the thigh bone, the thigh bone's connected to the knee bone," and so on.

When your bones are connected in this way, an action of one will likely create some kind of movement or effect — whether large or small — in adjacent, nearby and even not-so-nearby bones. This happens like a chain reaction. In the body, this set of linked movements is called the kinetic chain.

To get a real-life example of the kinetic chain in action, let's think about what happens when you walk.

1. First, you step forward with one leg.
2. Next, to move ahead, you bring your pelvis and trunk over the leg that just took the (previous) step. As the leg moves forward, it brings your pelvis on that side with it. The pelvis is part of the trunk, so the trunk automatically moves forward, as well.
3. This causes the pelvis on the other side to rotate back.
4. To keep facing forward as you walk, you turn your spine toward the leg and the pelvis as they extend (from steps 1 and 2 above.)

As you likely have noticed, one movement causes another. Some of the reactions are automatic (#2 where the pelvis and trunk are brought forward because the leg extends to take a step, for example) while others are a reflex (#4, where you need to be able to see where you're going).

You can move in either in open kinetic chain or closed kinetic chain. What's the difference?

Open kinetic chain happens when the part being moved is loose in space. Common examples of open kinetic chain movements include raising your arms over your head while sitting in a chair or lifting a leg while lying on your back. Most people think of open kinetic chain when they do exercises to strengthen their legs and arms, for example with free weights.

Closed kinetic chain happens when you fix the body part — usually an arm or leg against a hard, unrelenting surface. When the part is pressed against a wall or the floor, resistance is sent back into your trunk. (The body parts through which the resistance moves comprise the components of the chain for that particular movement or exercise.)

The yoga cat-cow stretch is a good example of a closed kinetic chain exercise, as are the feet in a hip bridge (shown).

Closed kinetic chain movements are often used to strengthen core muscles, stabilize posture, and train functional type movements.