Flexibility is important in day-to-day activities and sports. It allows for greater comfort and ability – and reduces your risk of injury.
To initiate movement, your muscles contract (shorten). How well they contract will depend on the initial resting length of the muscle.
And, for any movement, there is an optimum resting length to gain the optimum contraction your muscles.
For example …
Turning your head
Turning your head while driving is something we do regularly. This requires optimum resting length in your neck muscles and a muscle contraction. If the resting length of your neck muscles is less than optimum (shortened) , you won’t be able to turn your head to the desired range.
When you can’t turn your head it means some muscles are too tight and the optimum tension is not correct.
Bending over
Think about bending over to touch your toes. If you can’t bend over like you used to, your hamstrings may be too tight and need lengthening.
What is flexibility?
Flexibility refers to the mobility of your muscles and is defined as the Range Of Motion (ROM) of your joints or the ability of your joints to move through different planes.
There is a balance between the initial resting length of a muscle and the contraction of a muscle to build the right tension to move your joints. This impacts on the joint range of motion.
- If the resting length of a muscle is too long, or too short, it will affect the ability of the muscle to contract.
Why is flexibility important
Improves skill level
Good muscle and joint flexibility allow your joints to accommodate all the different angles required for everyday movements or sport-specific movements.
Decreases risk of injury
A balance between the length versus the tension of muscles reduces your risk of injury, particularly muscle tears or sprains.
There are several groups of muscles that show a tendency towards tightness.
These include the:
- hamstrings
- calf muscles
- pectoral muscles and some
- back muscles.
These muscles are often implicated in musculoskeletal pain, especially back pain and are prone to strains.
Increases efficiency
When muscle length and muscle contraction are optimised, you can obtain maximum muscle power and efficiency for your chosen sport or activity.
For example, when running …
If you have optimal length and tension in hamstrings, quads, hip flexors and gluteal muscles when you are running, this allows for:
- an increase in speed
- less fatigue over longer distances
- overall enhancement of your running enjoyment due to less pain in your legs and lower back
Flexibility can be limited by …
High muscle tone
High muscle tone occurs when the muscle is overworked or tense. Nerves supplying the muscle continue to provide a low-level discharge. This means the muscle cannot fully relax so the resting length is altered. This limits the full range of movement of the joint to which the muscle is attached.
Stretch reflex
As a muscle is rapidly stretched there is an automatic neuromuscular response – the ‘stretch reflex’ which limits overstretching to prevent injury. Where the length and tension relationship of a muscle is reduced, this reflex can start earlier, limiting the joint’s range of motion.
Change in muscle and connective tissue
As we age, muscle fibres are gradually replaced with fibrous connective tissue which is less elastic. This increases the stiffness of the joint, limiting the range of motion of the joint, particularly in highly mobile joints such as the shoulder and hips.
Bony change
Bony changes in the joints due to ageing or injury can affect how the surfaces of the joints line up decreasing flexibility and decreasing joint range of motion.
Poor posture
Poor posture can reduce the optimum length and tension relationship of skeletal muscle leading to stiffness in the joints as they are prevented from moving through their full ROM.
Try this activity and see if you notice the difference in your arm’s range of motion.
- Sit in a slumped position and raise your arms up over your head.
- Now sit on your sit bones, stack your spine up long and now raise your arms up overhead.
- Do you notice the difference?
Previous injuries
Injuries to muscles and connective tissue can lead to a thickening (fibrosing) of the soft tissue. Fibrous tissue is less elastic and can lead to decreased resting length of the muscle and reduced range of movement (ROM) in the affected joint.
