Muscle Contractions Flashcards

Muscle Contractions

• When a muscle has tension, it is contracting.

• A muscle can contract without causing movement.

• There are four types of muscle contractions:

Isometric Contraction

• Iso means "same" or "equal", and metric means "length".

• In an isometric contraction, the muscle length stays the same, but the tension changes.

• Example: Trying to lift something too heavy.

  • Muscles increase in tension but the length doesn't change because they aren't strong enough.

Isotonic Contraction

• Iso means "same" or "equal", and tonic means "tension".

• In an isotonic contraction, the tension stays the same, but the muscle length changes.

• There are two types of isotonic contractions:

Concentric Contraction

• The tension in the muscle initially increases until the amount of tension required to perform the action is reached, then the tension remains constant.

• While tension remains constant, muscle length decreases.

• Example: Performing a biceps curl.

Eccentric Contraction

• The tension in the muscle initially decreases until the amount of tension required to perform the action is reached, then the tension remains constant.

• While the tension remains constant, the muscle length increases.

• Example: Extending the elbow and lowering the weight down after a biceps curl (concentric contraction).

Proprioceptors

• Proprioceptors are structures in the body that detect the body's position in space.

• They allow awareness of body part locations, body weight, and center of gravity, even subconsciously.

• Proprioceptors are found in:

  • Skin

  • Muscles

  • Tendons

  • Ears

• The two main types of proprioceptors in muscles are:

  • Muscle spindles

  • Golgi tendon organs