Spasticity is one of the many secondary health effects caused by paralysis. People with a spinal cord injury, stroke, cerebral palsy, and multiple sclerosis most often have trouble with muscle spasticity, but it can affect anyone with an upper motor neuron lesion. That includes a wide range of neurological disorders and injuries, and it means that millions of people are affected by spasticity.
When most people think of spasticity, they imagine simple muscle spasms, where a muscle twitches involuntarily. However, spasticity, also known as spastic hypertonia, can be more accurately defined as “disordered sensori-motor control, resulting from an upper motor neuron lesion, presenting as intermittent or sustained involuntary activation of muscles’’ , and the effects of spasticity can range from slight muscle stiffness to intense, uncontrollable muscle spasms that can literally launch someone out of their chair.
Upper motor neuron lesions cause spasticity in much the same way that they cause paralysis and loss of feeling – by disrupting communication between the brain, the spinal cord, muscles, and the sensory system (sensory organs in the skin, muscles, tendons, etc.). Normally, if you want to relax a muscle, you only have to think about it, and your brain will communicate with your muscles through your spinal cord to make them relax. But if your brain or spinal cord is damaged, your muscles never get the message to relax. For this reason, if anything tells your muscles to activate, like a reflex that makes you pull away from something hot, the activation is often exaggerated or never stops. Spasticity can be triggered by movement, pain, discomfort, posture, and even other medical problems like urinary tract infections and pressure sores.
Many people with muscle spasticity have increased muscle tone, meaning that some of their muscles never relax fully and are always somewhat contracted. This increased tone, also known as hypertonia, can range from mild and uncomfortable to severe and debilitating, like rigidity. Hypertonia is most commonly seen affecting the upper limb, resulting in a constantly flexed elbow, bent wrist, and/or clenched fist.
Figure 1: Presentation of spasticity in the upper limb.
The other common presentation of muscle spasticity is hyperreflexia (exaggerated reflexes). When a reflex arc is activated in someone with spasticity, like when the patellar tendon is struck or you touch a hot stove and recoil, oftentimes the reflex will be exaggerated. In extreme cases, the reflex will repeat itself over and over again, echoing through the nervous system, which is known as clonus. Check out this video to see what hyperreflexia and clonus look like.
While spasticity is a symptom of a neurological disorder, it’s not always a bad thing. The table below lists some of the pros and cons of spasticity.
|Stiff muscles can help with some activities, like transferring from a wheelchair||Stiff muscles can hinder other activities, like getting dressed or brushing your teeth|
|Controlled reflex spasms can help with some activities, like standing & grasping||Uncontrolled reflex spasms can hinder other activities and lead to injury|
|Hypertonia and spasms work the muscles, preventing atrophy & bone density loss||Spasticity can be uncomfortable and even painful|
|Metabolic requirements of spasms can improve blood circulation and breathing||Extreme hypertonia can lead to joint contractures and pressure sores|
|Spasticity can be a warning sign that something else is wrong, like an infection||Extreme hyperreflexia can lead to injuries from collisions and falls|
For more on the pros and cons of spasticity, check out this video from the University of Washington.
If the cons of spasticity outweigh the pros, then treatment may be necessary. There are several options for managing spasticity, each with its own pros and cons:
There is a lot of confusion out there as to how electrical stimulation can be used to manage spasticity. Arjan van der Salm, a researcher from the Netherlands who wrote his doctoral dissertation on managing spasticity with electrical stimulation, provides a great analysis in his journal paper published in 2006 . He demonstrated that electrical stimulation does not reduce spasticity, but it does relax spasms, meaning that the muscle will spasm less for a period of time, usually for several hours after stimulation. This can be achieved by either stimulating the spastic muscle itself or by stimulating its antagonist. For example, if a person’s calf muscles (triceps surae) are spastic, electrical stimulation can be applied to the calf muscle or to the shin muscles (tibialis anterior), and either will relax the spasms. Van der Salm showed that stimulating the spastic muscle itself was most effective in relaxing spasms, probably because the stimulation fatigues the muscle and improves blood circulation to the muscle.
The takeaway here is that electrically stimulating a muscle can prevent spasms for several hours afterward, so it can be used as needed to manage spasticity.
There are many different factors to consider when choosing how to manage spasticity. The cause of spasticity, your situation and medical condition, and other factors like financing and support can all affect your decision. At the end of the day, a combination of methods will probably be best. For example, many people are fine with a low dose of medications combined with regular stretching and strengthening. It’s always best to consult your physician to find out what approach will be best for you.
For more information about spasticity, check out the resources below.
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The MyoCycle combines electrical stimulation with range of motion and strengthening exercise and is cleared by the FDA for general rehab for:
To learn more about managing spasticity with the MyoCycle, contact us.
Cleveland Clinic: Spasticity
National MS Society: Spasticity
MedlinePlus: Caring for muscle spasticity or spasms
UAB-SCIMS: Spastic Hypertonia Spasticity following SCI
CareCure: FAQ about implanted drug pumps for managing spasticity
 Pandyan AD, Gregoric M, Barnes MP, Wood D, Van Wijck F, Burridge J, Hermens H, Johnson GR. Spasticity: clinical perceptions, neurological realities and meaningful measurement. Disability and Rehabilitation 2005;27(1/2):2-6.
 Taylor-Schroeder S, LaBarbera J, McDowell S, Zanca JM, Natale A, Mumma S, Gassaway J, Backus D. The SCIRehab project: physical therapy treatment time during inpatient spinal cord injury rehabilitation. The Journal of Spinal Cord Medicine 2011; 34(2):149-161.
 van der Salm A, Veltink PH, Ijzerman MJ, Groothius-Oudshoorn KC, Nene AV, Hermens HJ. Comparison of electric stimulation methods for reduction of triceps surae spasticity in spinal cord injury. Arch Phys Med Rehabil 2006; 87:222-228.