Flexibility

Flexibility is the range of movement (ROM) around a joint. This flexibility can be increased by stretching the muscles and tendons that cross the joint.

The Aims of stretching are usually to achieve one or more of the following:

To increase muscle length
To reduce injury risk
To improve repair of an injured muscle
To improve performance
To reduce pain caused by muscle stiffness

There are 3 commonly used types of flexibility training:
Static
Dynamic
PNF (proprioceptive neuromuscular facilitation)

STATIC STRETCHING: This is where the muscle is slowly stretched to the point at which a gentle stretch is felt. This causes a stretch reflex which relaxes the muscle after 10-15 seconds allowing a further stretch to be performed.
This type of stretching is most effective when performed passively. This means that the stretch is eased into position to help the relaxation. A partner can sometimes assist with this type of stretch.

DYNAMIC STRETCHING: This type of stretching is not recommended for use in a health and fitness programme due to the injury risk. This ballistic type of stretching is however often used by sports people prparing for events that have dynamic movements. eg. Gymnasts and Hurdlers.

PNF: This type of stretching is very effective, but is also an advanced technique that requires good skill to perform it. This stretch relies on the Golgi Tendon Organ totally relaxing the muscle after a maximal contraction. If you would like to learn this technique I suggest you consult with a Physiotherapist, Personal Trainer or Athletics Coach.

Static stretching is the type of stretching most likely to be used in a health and fitness situation. The recommendations to get the most benefit from this type of stretching ( as Suggested by Tha American College of Sports Medicine ACSM ) are:

Frequency: 2-3 times per week

Time: 4 x 10-30 Seconds

There has been a lot of research into stretching over recent years. Below I will briefly mention a few of these.

A study by Bandy and Irion in Physical Therapy in 1994 found that by stretching muscles daily for 30 seconds there continued to be flexibility gains for 6 weeks before a plateau was reached. If the stretches were only held for 15 seconds it took 10 weeks to achieve the same results.

The Journal of Strength and Conditioning Research Vol 15 found that static stretching before a vertical jump test decreased performance by 7.5%. Because of the ballistic nature of this event dynamic stretching would probably be more beneficial.

A report by Amako et al in Military Medicine June 2003 found that recruits who practised 18 static stretches before and after training had a significantly lower rate of muscle related injuries. However there was no difference in bone and joint injuries.