There are two types of muscle contraction; these are Isometric and Isotonic Contractions.
A muscle will contract upon stimulation, in an attempt to bring its attachments closer together, but this does not necessarily result in the muscle shortening. If the contraction of muscle results in the muscle creating movement of some sort, the contraction is called isotonic. If no movement results in contraction then this is called isometric.
An Isometric contraction occurs when a muscle increases its tension, but the length of the muscle is not changed at all. For example if you were to hold a heavy weight in the hand with the elbow held stationary and bent at 90 degrees. You will find that some of our postural muscles are consistently working in an isometric contraction, such as our calf’s which stop us from falling forwards at the ankle.
It is the isotonic contractions of muscle that enable us to move about. There are two types of this contraction.
In concentric contractions, the muscle attachments move closer together, causing movement at the joint which causes the muscle to shorten. A good example of this is when you’re holding an object in your hand, if the biceps muscle contracts concentrically (shortening), the elbow joint will flex and the hand will move towards the shoulder.
An eccentric muscle contraction is a type of muscle activation that increases tension on a muscle as it lengthens. Eccentric contractions typically occur when a muscle opposes a stronger force which causes the muscle to lengthen as it contracts. Examples of this are actions such as going down stairs, running downhill, lowering weights and the downward motion of squats, push ups or pull ups. Eccentric contractions are common to many sports in which you need controlled or resisted types of movements.
Eccentric contractions are associated with the delayed onset muscle soreness (DOMS). Eccentric muscle contractions also appear to be associated with greater muscle strengthening than when using concentric contractions.
How we can help
Physiotherapists have a vast medical and anatomical knowledge of massage and other manual techniques and these can be used to restore muscle length, reduce friction between structures and relieve pain and muscle spasm. All of this allows normal function to be restored in the maximum time. To see how we can help, click the links below for further information and to book your place.
Post by Emma James – April 2016