WHAT IS SPASTICITY?
Spasticity is the overexcitability of a muscle in response to movement. It’s a hyper exaggerated stretch reflex. Essentially when a joint is moved quickly the muscle tightens. This signal to tighten the muscle isn’t coming from the brain, but rather that the brain has difficulty sending signals to stop the reflex from happening.
Spasticity has also been used as a general term to describe other symptoms seen in conditions where damage to the central nervous system has occurred. Symptoms such as a sustained muscle contraction at rest, which makes movement of the joint rigid and inflexible. This can cause joint contractures. You might also see a muscle tightness when you're trying to perform an activity with your other hand.
There are several mechanisms that contribute to spasticity in people with spinal cord injury. Typically the brain stem is able to manage the rate of motor neurons that are firing. Depending on the level of injury the brain stem is unable to send a message to a particular muscle below the level of injury. The muscle contraction becomes a reflex loop from the muscle to the spinal cord and the brain is unable to reach the muscle to stop it because the pathway has been cut off.
People with spinal cord injury also have difficulty sending a message to the antagonist muscle. Each joint movement has an agonist (primary muscle mover) and an antagonist (stabilizing or opposing) muscle. For example, the elbow joint is moved by the biceps and triceps muscle. To bend the elbow the biceps muscle fires up, but the triceps muscle is also involved to manage the timing of the movement and release back to a neutral position. Each joint and each movement typically use a combination of muscles to allow smooth movement of upper and lower body extremities.
It’s important to note that not all spasticity is bad. Many people with spinal cord injury use their spasticity to assist with standing, transfers, and daily activities. It’s important to discuss options for managing spasticity and functional implications with your physician and your occupational or physical therapist.
There are two general approaches that address spasticity: medical management and physical management. Medical management is decided in collaboration with the patient and physician. It addresses the neural component that is causing the muscle tightness. Medical management of spasticity includes oral medications, neurotoxin or phenol injections, and surgical interventions.
The physical management is typically addressed by a physical or occupational therapist and addresses the biomechanics of the joint to prevent muscle shortening, joint deformities, and decreased function. Physical management includes proper positioning, stretching, and muscle strengthening. Physical and occupational therapists also use electrical stimulation and ice as modalities to limit spasticity during exercise or functional activity.
Proper positioning should be considered when seated and lying down. Supports should be given to keep the joints in alignment and symmetrical. When lying down, use pillows or towel rolls to prevent scissoring or a windswept position of the legs. If using a wheelchair, positioning can assist with extensor tone in the hip when the feet are supported. Wheelchair arm supports can also help support the arms, which will prevent dangling and accidental activation of the stretch reflex. If you’re having difficulty with extensor tone in the legs, manually moving one knee into flexion can break up the tone to position the hips in the wheelchair.
Spasticity tightens our muscles and over time the muscle begins to shorten. This limits our ability to move our joints even further. Stretching has the potential to quiet the hyper exaggerated reflex for several hours, as well as the benefit of maintaining range of motion. Stretches should be held for 30 seconds or more and you may feel a release of the muscle tone.
Splinting and orthotics are used for an even longer stretch. They position a joint optimally to maintain length of a muscle and prevent contractures. Depending on the purpose, splints and orthotics are worn during the day or at night to allow for hours of stretch time.
Weight-bearing and standing are also forms of prolonged stretching with the added benefits of strengthening and increasing bone density. Weight-bearing also inhibits the reflex movement pattern.
Strengthening can improve spasticity in two ways. By strengthening the antagonist (opposing) muscle, it can help inhibit the reaction of the spastic muscle. When the spastic muscle activates and tries to pull a joint into flexion, the extensor muscle has the capacity to limit the flexion just by being stronger.
We must also strengthen the spastic muscle. It might seem that with all that contracting a spastic muscle would be a strong muscle, but without the brain to muscle connection a spastic muscle is actually a weak muscle. Utilizing electrical stimulation or ice prior to strengthening a spastic muscle may be a way to optimize your strengthening session.
Strengthening can happen any time a muscle is contracted, but depends on the capability of the person doing the contracting. It has to be somewhat difficult. The muscle has to fatigue. The person who does not have full active range of motion, but is able to visibly contract a muscle is strengthening with each repetition of movement.
Repetition of movement is a rehabilitation strategy not only for strengthening, but plasticity. Intensive repetitive training or massed practice enhances sensory motor recovery after spinal cord injury.
INTENSIVE REPETITIVE TRAINING
Voluntary movement has the potential to maintain joint range of motion, strengthen, and increase plasticity. But it’s all about repetition. In a typical therapy session, you might expect to do 20-30 repetitions of movement. You would be responsible for completing the movements for each joint on a daily basis. This can become boring and the habit slowly slips away.
Talk to your therapist to help find motivating exercises and activities that encourage you to complete lots of repetitions within your capabilities. Staying engaged to maximize repetitions performed is key. Every person is unique and has a different rehabilitation journey. Neofect has experienced occupational therapists to consult with to see what might work for you.
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All content provided on this blog is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. If you think you may have a medical emergency, call your doctor or 911 immediately. Reliance on any information provided by the Neofect website is solely at your own risk.
- Clarice Torrey, OTR/LClarice is an occupational therapist, product designer, and health writer based out of San Francisco, CA. Clarice works for RAD Camp as a Community and Product Manager.