Pro Motion Physiotherapy & Sports Injury Clinic

Stretching

Why Stretch?

Mobility and flexibility of the muscles, skin and other soft tissues which surround each joint in the body, is essential for normal range of motion. Due, in part, to prolonged immobilization, injury, poor muscle training programs, and poor posturing, joint motion becomes restricted and stretching is required to restore 'normal' range. Stretching may also be beneficial for enhancing physical fitness, mental and physical relaxation, and coordination. It may also help to decrease muscle tension and soreness.

What Happens When We Stretch?

Skeletal muscles are made up of many small fibers. These fibers are made up of small units called sarcomeres which are able to contract and relax. When a muscle is stretched, the sarcomeres lengthen, allowing the joint to move further. Specialized stretch receptors, known as muscle spindles, are found in the middle portion of each muscle and record the velocity and duration of the stretch. If a muscle is stretched too fast, a message is sent from the muscle spindle to the rest of the muscle causing an increase in the tension in the muscle and thus limiting the motion. This is known as the stretch reflex.

Another specialized receptor in skeletal muscle is the Golgi Tendon Organ (GTO). It surrounds the ends of the muscle fibers and records the tension in the muscle. When excessive tension develops in the muscle, the GTO responds by causing the muscle to relax. This prevents injury to the muscle when heavy weights are lifted, but also allows the muscle to relax and stretch when a slow, low grade force is applied.

Stretch Tolerance

Decreased pain and increased ease of stretching associated with repeated stretching is known as stretch tolerance. It is an increase in this tolerance, rather than an increase in muscle length that is thought to be responsible for increased range of motion with short, periodic sessions of stretching.

Whenever you stretch, it is ideal to isolate and stretch only one muscle or group of muscles at a time. (For example, it is better to stretch your hamstrings one leg at a time, rather than trying to stretch both legs together.) Breathing should be slow and relaxed while stretching for best results.

Types of Stretching

Static Stretching: consists of stretching a muscle to its’ farthest point and holding this position for a set amount of time. The low force, sustained stretch will affect the GTO and allow the muscle to relax and lengthen. This is the type of stretching that should be done initially in your warm up and cool down.

Dynamic Stretching: consists of moving a part of your body, increasing speed and reach of movement until full range is attained. This is a very controlled type of stretching and does not involve any bouncy or jerky motions and does not stretch the muscle beyond its' normal range. Examples are large circles with your arms or swinging you legs forward and backward. This type of stretching is beneficial during warm-up after your static stretching. It will help improve flexibility while moving, which is important during any sport or aerobic activity.

Ballistic Stretching: consists of using the momentum gained through movement of the body in an effort to force the muscle beyond its’ normal range. This type of stretching will trigger the stretch reflex which prevents the muscle from lengthening and has potential to cause damage to the muscles and soft tissue surrounding the joints. Thus, this type of stretching should be avoided.

How long to Stretch

The purpose of the stretch will determine the length of time a stretch needs to be held. If The stretch is part of a warm-up or cool-down, 20 seconds is considered long enough (7-10 seconds in growing children). If the stretch is being applied to increase range of motion at a joint because there is a limitation in movement due to injury or prolonged immobilization, the stretch must be held 20 minutes or longer. This allows for a more permanent change in muscle length as new sarcomeres are added to the muscle.

When to Stretch

Muscles respond best to stretch after they have been warmed up. Thus, it is important to do some short, low intensity, aerobic work (eg. light jog) before stretching. It is also wise to stretch as part of your cool down in order to help in the removal of waste products created as a result of your activity.

In order to promote muscle growth, and to prevent adhesions from forming in the healing muscle, it is also advisable to stretch following a strength workout in the gym.

When NOT to stretch

It is advisable not to stretch under the following conditions:

• after a recent fracture
• if a joint is inflamed (red, hot and swollen)
• if there is sharp pain with the movement
• if the shortened tissue around a joint is actually providing stability to that joint
• if the muscle is weak and already overstretched

Physiotherapy and Stretching

Many injuries sustained to joints, tendons, ligaments and bones result in adhesions in the tissues and limited range of motion. Immobilization (eg. casting) can cause further limitation of motion and weakening of surrounding tissues. At Pro Motion Physiotherapy we include the use of special techniques to facilitate the lengthening of muscles and surrounding soft-tissue and the breaking down of adhesions. Specific exercises and use of therapeutic equipment are also used to enhance tissue healing/lengthening.