Structure of a Muscle

Review of Muscle Tissue

Skeletal Muscle

Composed of large serrated fibres which may vary in thickness and length (up to 30cm in length) depending on the part of the body they are situated in and the muscle’s function. It has a very rich blood supply.

A muscle is made up of thousands of muscle fibres. Each fibre is enclosed in a connective tissue sheath (endomysium).

The single cells are bound together in bundles (fascicule) and enclosed in a connective tissue sheath (perimysium).

All the bundles are enclosed in a connective tissue sheath (epimysium).

Properties of Muscles

1. Contractability -  The unique quality of muscle which enables it to shorten at will.

2. Extensibility – Muscles are elastic and can stretch. They can increase their length by up to 50%.

3. Elasticity – After stretching, the muscle will return to its resting length and beyond.

Muscles can produce three types of contractions:

1. Concentric – a concentric contraction is one where the muscle contracts in order to overcome a resistance (usually gravity) and in doing so, the proximal and distal attachments move closes together. Sometimes referred to as dynamic shortening.

2. Eccentric – an eccentric contraction is one where the muscle dynamically lengthens under tension in order to overcome resistance and in doing so the proximal and distal attachments move further apart.

3. Static (Isometric) – a static contraction is one where the muscle is one where the muscle contracts but the proximal and distal ends remain the same distances apart, there is no joint movement but tension within the muscle increases.

As you can see a muscle moves and contracts in different ways and as a Sports Therapist it is vital that one rehabilitates the muscle with in the actions it produces. If not the muscle has a greater risk of re-injuring.

 


Added by :Eddie Jackman
Acupuncturist,Physical Therapist and Sports Therapist based in Waterford
For treatments or appointments please call 087 6701166