General Fitness>>Flexibility Training - 1/6/2007
Flexibility is a very important, but often neglected, fitness component. How many times have you jogged, wheeled, or performed a workout without taking the time to stretch? You must remember that balanced muscle length and unrestricted movement around your joints are necessary to avoid injuries.
Flexibility is the maximum ability to move a joint or a combination of joints through a range of motion. Many factors can influence your flexibility, including muscle temperature and elasticity, the distensibility of the joint capsule, and the extensibility of your ligaments and tendons. Not everyone has the same available movement—flexibility is related to your age, gender, and physical activity. Evidence suggests that girls are more flexible than boys and that exercise improves flexibility. Weight training has been found to increase flexibility if the exercises are performed using a full range of motion in the same plan of motion as the one in which flexibility is measured.
Not only do people have different degrees of flexibility, but flexibility can vary in different areas of the same body, for example, the hamstring muscle group is often tighter than the quadriceps muscle group. Repetitive movement patterns using the same muscle groups (e.g., wheelchair propulsion) and habitual postures (e.g., sitting in a chair with rounded shoulders)
can promote muscle tightness or decrease flexibility. This decrease in flexibility can then cause improper or inefficient movement. Also, when a muscle is tight, it tends to lose sensation. This sequence of muscle tightness causing altered movement patterns and decreased sensation shows how lack of flexibility in one area can cause injuries in another.
It is possible to improve flexibility at any age with appropriate training.
Both muscle and joint flexibility is best improved by regular stretching routines, so flexibility training requires knowledge of joint range of motion and muscle reactions to stretching. Stretching exercises can be used to
- Increase range of motion,
- Maintain available range of motion,
- Improve posture,
- Reduce muscle sores,
- Prevent musculoskeletal injuries,
- Provide relaxation and relieve neuromuscular tension, and
- Control spasticity.
These benefits illustrate the importance of including stretching for flexibility in an exercise routine. Optimizing your flexibility can allow for more efficient movement that will enhance mobility and sports skills as well as prevent injuries.
When Should I Stretch?
Stretching should always be included as part of your warm-up; however, you should not just jump in and start stretching your cold muscles. Like an old car in the winter, your muscles require some time to warm up. The ability to perform physical work tends to be improved at elevated body temperatures. Gentle physical activity allows the blood to circulate to the muscles and tendons, which warms them up and makes them more pliable. This will reduce the potential risk of stretching-induced injuries.
Simple warm-up activities can include rolling your shoulders forward and backward and slow wheelchair propulsion. Arm circles, clockwise and counterclockwise, are also excellent general activities to warm up the whole arm. If you are going to perform leg exercises, walking or a slow job may be useful to increase the circulation to the working muscles of your legs. Gentle riding on a stationary bicycle for 3 to 5 minutes is also a good activity. Once you have increased the circulation to your working muscles, you can perform gentle static stretching to prepare your muscles for your workout. The static stretching should concentrate on the muscles and movement specific to the activity or exercise that you are going to perform, for example, arm stretching for wheelchair basketball and leg stretches for resistance exercise with the legs. Again, a warm and stretched muscle is less likely to be injured during your workout.
The cool-down phase of your workout should also include stretching. In your cool-down you again want to exercise at a submaximal level for 5 to 10 minutes to prevent muscle cramps and allow your heart rate and circulation to return to their pre-workout levels. You then should perform your warm-up stretching routing again. At this point in your exercise program the muscles are warm and most pliable so additional flexibility can often be achieved, making this a good time to work on problem spots or tight areas. Stretching during cool-down also helps decrease the muscle soreness that tends to occur 24 to 48 hours after strenuous activity.
Principles of Stretching
Before we address exactly how to stretch and identify some techniques, we need to discuss the principles of safe, effective stretching. The three main principles of stretching, as with aerobic exercise, are frequency, intensity, and duration. Monitor and adjust all three according to your specific functional range of motion limitations.
Stretching exercises need to be performed at least three times a week to maintain flexibility. You can progress to daily stretching routines, especially if spasticity is present and functional range of motion is essential to perform your daily activities. Whole-body stretching is necessary to maintain functional range of motion so you can perform the activities of daily living, even if you are nonambulatory. For example, if you use a wheelchair for locomotion, stretching your legs may not relate to wheelchair propulsion but it can assist with proper positioning in your wheelchair and with the ability to get the lower half of your body dressed.
Stretches should be done in the warm-up and cool-down phases of your exercise program. They can also be done while you are resting between sets of exercises. You should perform 1 to 3 repetitions of each stretch, but you can increase the number of repetitions if the goal is to increase range of motion in a particular area. For example, if you have tight heel cords and want to work on fast walking on the treadmill, it would be beneficial to stretch your heel cords and other leg muscle after a 3 to 5 minute warm-up of walking. However, you would want to concentrate on performing at least two static stretches of both heel cords for 30 to 60 seconds before and after the exercise; the other leg muscles may only require one static 3 second stretching before and after the exercise.
In regard to stretching, intensity refers to how much tension is produced by the stretch. The degree of stretch can be increase or decrease by the amount of time the stretch is held and the amount of external force applied to produce the stretch. The tension produced should not cause pain—pain means you have pushed too far. Begin high-intensity stretching to gain range of motion with proper medical instruction. To avoid damage to the joints and muscles, never stretch a multijoint muscle maximally over more than one joint at any time. For example, the quadriceps muscle group stretches across the front of the knee and hip. You should stretch this muscle group by lying on your stomach and rasping one leg above the ankle with a flexed knee. Do not maximally force the knee to flex or you could damage the knee joint, the quadriceps muscles, or both.
Again, there should be no pain when you stretch; you should feel only slight tension that slowly diminishes with the stretch. Apply stretches gradually, building to a maximum as the tissues release, and then remove the stretch gradually to prevent rebound or tightening of the muscle. When stretching after a workout to gain range of motion, apply slightly more tension than when stretching before a workout.
How long you hold a stretch contributes to the intensity. Static stretches should be maintained for 10 to 60 seconds. Use a variety of moderate-intensity 10 second stretches to warm up for an activity. A 60-second moderate-intensity stretch may be used with spasticity (e.g., multiple sclerosis, cerebral palsy, spinal cord injury) or coordination problems (e.g., head injury, stroke) to stretch and relax a specific muscle group. Begin general stretching for 10 seconds and then increase the time and intensity according to the tightness of the muscle group. Stretch for longer periods after workouts (during cool-down) to increase range of motion and decrease muscle soreness.
BASIC STRETCHING RULES
- No bouncing. Hold static stretching to build up soft tissue tension so change can occur in tissue length. Bouncing can tear tissues or cause injuries in other affected areas.
- No pain. Stretching should cause a sensation of discomfort or tension; pain indicates that you have pushed too far.
- Do not hold your breath. Exhale with short-duration stretches and breathe slowly and rhythmically with longer duration stretches so you are relaxed and focused on the muscles you are stretching.
- Know what you are stretching and why. Each individual and sport has different flexibility requirements; individual assessments are required to recognize tight and unstable areas.
- Watch for muscle substitution and make sure the proper group is being stretched.
Precautions With Stretching
If you have any of the following conditions, check with a physician or physical therapist before implementing a flexibility routine. You need to be knowledgeable about the structural stability of your bones, joints, and muscles and understand restrictions or precautions that you may have to follow both with stretching and with exercise. For example, if you have a history of joint laxity at the knee, you may have to wear a knee brace to help control this laxity during stretching and exercise.
These conditions require professional clearance:
- Sever spasticity with resultant joint contractures; the presence of a joint contracture or deformity
- The diagnosis of osteoporosis or heterotopic ossification
- A history of joint laxity (hypermobility), or joint subluxation (partial dislocation), or joint dislocation
- A surgical history with resulting scar tissue, tissue adhesions, joint fusions, or placement of instrumentation to stabilize a fracture
- Pain that limits movement or that has not yet been evaluated by a physician or physical therapist
Contraindications With Stretching
The following existing conditions indicate that a stretching routine should not be performed at all or only by a medical professional. These conditions need to be evaluated and monitored by a medical professional to prevent injury;
- An infection in an extremity or joint
- Excessive swelling in a joint
- Sever, painful joint crepitus
- An open wound in the area you want to stretch
- The onset of pain in an extremity
- New joint instability or laxity that has not yet been evaluated by a physician or physical therapist
Stretching Techniques for Developing Flexibility
Review the following techniques of stretching so you are aware of the most appropriate way to stretch based on your physical disability as well as your strength and muscular control.
Range of Motion (PROM)
Use this type of range of motion when you require assistance from a partner or when one body part is stabilized to stretch another part. Passive means there is no active muscle contraction while the joint is being moved through its range of motion. Slow, rotational passive range of motion can be used to decrease tight muscles around a joint for people who lack or have inadequate muscle control, the presence of spasticity, or both, as with spinal cord injury, cerebral palsy, and multiple sclerosis. However, when sensation is lacking, such as in complete spinal cord injury or stroke, PROM should be performed only by medically trained personnel to prevent stretch-induced injuries.
Active-Assisted Range of Motion (AAROM)
If you can perform an active muscle contraction but are too weak to perform the entire motion, after a stroke, for example, or if you have a neuromuscular disease, you will require a partner's assistance to stretch through the complete range of motion. When someone is assisting you with range of motion, you must know your functional range of motion, or your own limits, so stretch-induced injuries do not occur. AAROM can also be used to enhance the warm-up and cool-down phases of exercise and athletic events.
Active Range of Motion (AROM)
This type of range of motion is done with no assistance. It requires an active muscle contraction and joint movement to elongate the opposing muscle group. Active range of motion is often used for general whole-body warm-up and stretching. AROM does not develop as much range of motion as passive or active-assisted range of motion.
Static stretching is the preferred mode of stretching for most individuals because if done properly there is little risk of injury. Static means that the stretch is held constant for a certain range of motion around one or a sequence of joints.
Dynamic stretching is a more specific mode of stretching for sport-specific movements. Sometimes referred to as ballistic stretching, it involves resistance in a joint to movement. Dynamic stretching often involves quick motions that are generally recommended only for highly conditioned athletes. Dynamic stretching should never be performed if you have spastic muscles. This type of stretching may increase your abnormal muscle tone, which could actually decrease your range of motion.
Proprioceptive Neuromuscular Facilitation (PNF)
PNF is a training method mused in the physical therapy setting to promote the response of neuromuscular processes related to voluntary and involuntary movement by stimulating the appropriate proprioceptors. It is beyond the scope of this flexibility chapter to fully discuss the principles and procedures of PNF, but an introduction to the so-called PNF or super-stretch techniques used in athletic conditioning can add to your understanding of exercising for flexibility.
PNF uses specific relaxation techniques to help enhance functional flexibility. Two of these techniques, contract-relax and hold-relax, comprise only a small aspect of PNF flexibility training, but they are popular because they help increase the functional range of motion by promoting relaxation of the working muscle so it can be stretched to increase range of motion. Both techniques are performed with an assisting partner who places the extremity with the tight target muscle in a stretched (lengthened) position.
Contract-Relax. This technique involves an isotonic active contraction of the target muscle against maximal resistance by the partner. The contraction is often carried out for a count of 5 to 10 seconds, followed by a relaxation phase. The partner then passively moves the relaxed extremity to stretch the target muscle to its new range of motion limit. The technique is then repeated, each time from a new point of greater elongation. The number of repetitions depends upon the functional goal of the stretch. This technique is often better than hold-relax (described next) for muscles that act over two joints (e.g., hamstrings) instead of a single joint (e.g., pectoralis major).
Hold-Relax. This technique is similar to contract-relax except that it uses an isometric rather than an isotonic contraction against maximal resistance before the relaxation phase and passive movement to the new limit. This technique is helpful when there is some pain in the extremity, possible with muscle spasms, because the athlete does not have to actively move.
Both the contract-relax and hold-relax techniques are helpful when someone has spasticity in the extremity or is not able to move through the full range of motion. It is often beneficial, however, for the person to perform the full motion actively without any resistance other than gravity or the weight of the extremity after using the techniques.