Skeletal Muscle Contractions: Types (Nursing)

00:01 So now let's switch gears again and talk a little bit about different types of muscle contractions that can occur.

00:08 So you have isotonic muscle contractions.

00:11 In which the tension is constant while the muscle length is changing.

00:17 If the muscle length gets smaller, it is referred to as a concentric isotonic contraction.

00:24 And if the muscle length increases, it is referred to as an eccentric isotonic contraction.

00:33 The other type of muscle contraction is isometric.

00:37 And this we contract the muscles but we do not change the length.

00:42 A good example of this is doing wall sits.

00:46 So, as you can see in this demonstration, we're looking at both concentric and eccentric isotonic contractions.

00:55 So as they move the weight up toward the shoulder, they're exhibiting a concentric contraction.

01:01 The muscle length is shortening as the muscles contract.

01:05 As we move the weight back down toward the hip.

01:08 This is an eccentric contraction.

01:10 And this case the muscle length is lengthening and the muscle is contracting.

01:16 Now, we are exhibiting isometric contractions.

01:21 And this demonstration, the weight is just being held and has not moved.

01:26 The muscles are still having to contract in order to hold the weight up, but there's actually no change in the length of the muscle.