What Is Spasticity?

Spasticity is a form of involuntary muscle overactivity that can develop after an injury or disease affecting the brain or spinal cord. It may cause muscles to feel tight or stiff, produce spasms, restrict smooth movement and make everyday activities more difficult. Spasticity is commonly associated with stroke, cerebral palsy, multiple sclerosis, traumatic brain injury and spinal cord injury.[1,2]

The experience is different for every person. Mild spasticity may feel like intermittent tightness, while more pronounced spasticity can affect walking, hand use, positioning, hygiene, sleep, comfort and caregiving. Importantly, increased muscle tone is only one part of a broader movement problem. Weakness, impaired motor control, pain, sensory changes and soft-tissue shortening may also influence function.[1,3]

Key takeaways

• Spasticity results from damage to the central nervous system, not from a problem located only in the muscle.
• Common features include muscle stiffness, resistance to fast stretch, spasms and abnormal limb postures.
• Treatment is not automatically required simply because spasticity is present.
• Assessment should focus on the person’s goals, function, comfort and risk of complications.
• Management may combine rehabilitation, medication, botulinum toxin, splinting, positioning or advanced interventions.
• Reducing muscle tone does not by itself guarantee better function; treatment should be linked to meaningful goals.[1,3]

What happens in spasticity?

Movement depends on a complex network of signals travelling between the brain, spinal cord, peripheral nerves and muscles. After the pathways that regulate movement are damaged, the balance between excitatory and inhibitory signals can change. Muscles may then respond too strongly to stretch or become active at inappropriate times.

The classic clinical definition describes spasticity as a velocity-dependent increase in resistance to passive stretch: the faster a clinician moves a joint, the greater the resistance may become. Modern clinical guidance also recognizes that people may experience a broader group of positive upper motor neuron features, including spasms, clonus and involuntary muscle activation.[1,4]

Spasticity should not be confused with every form of stiffness. A joint can also become difficult to move because of contracture, pain, swelling, rigidity or structural changes. A professional assessment helps determine what is causing the restriction and which treatment is most appropriate.

What causes spasticity?

Spasticity can occur when a neurological condition affects the brain or spinal cord. Common causes include:

• Stroke
• Cerebral palsy
• Multiple sclerosis
• Traumatic brain injury
• Spinal cord injury
• Brain or spinal cord tumors
• Other acquired or inherited neurological conditions

The pattern depends partly on the location and extent of the neurological injury. After stroke, for example, the arm may tend toward a bent elbow, inward-turned forearm, flexed wrist or clenched hand. The leg may become stiff at the hip, knee or ankle. These patterns vary and should not be assumed without assessment.

What are the symptoms of spasticity?

Possible signs and symptoms include:

• A feeling of muscle tightness or stiffness
• Resistance when another person moves the limb
• Involuntary spasms or sudden movements
• Repetitive rhythmic movement known as clonus
• A clenched hand, bent elbow or pointed foot
• Difficulty opening the hand or placing the heel on the ground
• Pain, disturbed sleep or difficulty maintaining a comfortable position
• Problems with dressing, washing, nail care or skin hygiene
• Reduced ability to reach, grasp, release, stand or walk

Symptoms can fluctuate. Pain, infection, constipation, bladder problems, skin irritation, fatigue, stress and poor positioning may aggravate spasms or muscle overactivity. A sudden or unexplained change deserves clinical attention, particularly when it may reflect an underlying medical problem.[1]

Can spasticity ever be helpful?

Yes. In some situations, increased tone may help a person maintain posture, stand, transfer or support a limb. Treating it too aggressively could reduce this compensation and reveal underlying weakness. This is why good management does not aim to eliminate all muscle tone. The goal is to address spasticity when its disadvantages outweigh its benefits and when treatment supports a specific, meaningful outcome.[1,3]

How is spasticity assessed?

There is no single test that captures the full impact of spasticity. A comprehensive assessment may include:

• The person’s priorities and treatment goals
• When symptoms occur and what triggers them
• Passive and active range of motion
• Muscle tone and resistance to movement
• Strength and selective motor control
• Pain, skin integrity and limb position
• Walking, hand use and daily activities
• The effect on sleep, hygiene, caregiving and participation

Clinicians may use measures such as the Modified Ashworth Scale or Modified Tardieu Scale, but these should be interpreted alongside functional and goal-based outcomes. Consensus guidance emphasizes individualized assessment and treatment planning rather than relying on a tone score alone.[1,4]

When does spasticity need treatment?

Treatment may be considered when spasticity contributes to:

• Pain or frequent disturbing spasms
• Difficulty with hygiene, dressing or caregiving
• Reduced movement or function
• Sleep disruption
• Unsafe positioning or mobility
• Skin damage or pressure-related problems
• Progressive loss of range or risk of contracture
• Difficulty using a splint, wheelchair or other equipment

Treatment goals should be concrete. Examples include making palm hygiene easier, reducing painful spasms, improving foot placement, supporting a home exercise program or enabling more comfortable positioning.

How is spasticity treated?

Management is personalized and often multidisciplinary. Options may include:

Rehabilitation

Occupational therapy and physiotherapy can address movement, strength, positioning, task performance, self-management and participation. WHO describes rehabilitation as a person-centered process intended to optimize functioning and reduce disability.[5] Evidence for individual non-pharmacological techniques varies, so programs should be selected according to the person’s presentation and goals.[6]

Botulinum toxin

Botulinum toxin can be injected into selected overactive muscles to produce a temporary, localized reduction in muscle activity. It is generally used for focal or multifocal spasticity and should be paired with clear goals and an appropriate rehabilitation plan. Reduced tone is not the same as restored function, so outcomes must be assessed in terms of what matters to the individual.[1,7]

Oral medication

Medicines such as baclofen or tizanidine may be considered when symptoms are more generalized. Potential benefits must be balanced against side effects such as sedation or weakness. Medication decisions require an individualized medical review.[1]

Splinting, positioning and assistive technology

Selected people may benefit from splints, casts, seating modifications, positioning strategies or assistive devices. These interventions should be fitted and monitored by qualified professionals to avoid pressure, pain or loss of function.

Advanced interventions

Intrathecal baclofen, phenol neurolysis or surgical procedures may be considered in selected cases when less invasive approaches are insufficient. These require specialist assessment and careful discussion of benefits, risks and long-term follow-up.

Why multidisciplinary care matters

Spasticity can affect body structures, activity, participation and caregiver burden at the same time. Depending on the person’s needs, care may involve a rehabilitation physician, neurologist, occupational therapist, physiotherapist, nurse, orthotist, surgeon or other professional. Coordinated care helps connect medical treatment to real-world goals.[1,5]

When should you seek professional advice?

Arrange an assessment if muscle stiffness or spasms are painful, worsening, interfering with daily activities, making hygiene difficult or reducing movement. Seek timely medical advice for a sudden increase in symptoms, especially when accompanied by fever, new weakness, severe pain, skin injury or a change in bladder or bowel function.

Frequently asked questions

Is spasticity the same as muscle tightness?

No. Spasticity is a neurological form of muscle overactivity. Tightness can also result from contracture, pain, joint changes or other causes.

Can spasticity be cured?

Treatment can often reduce specific symptoms and improve comfort, care or function, but the underlying neurological injury may remain. Outcomes depend on the cause, severity, goals and accompanying impairments.

Does all spasticity require treatment?

No. Treatment is appropriate when spasticity causes problems or creates a meaningful risk, and when the expected benefit outweighs possible disadvantages.

Which professional treats spasticity?

Assessment is often led by a rehabilitation physician, neurologist or specialist multidisciplinary team. Occupational therapists and physiotherapists play important roles in assessment, goal setting and rehabilitation.

Medical disclaimer

This article provides general educational information and does not replace personal medical assessment, diagnosis or treatment.

References

1. Verduzco-Gutierrez M, et al. AAPM&R consensus guidance on spasticity assessment and management. PM&R. 2024. Consensus guidance
2. American Academy of Physical Medicine and Rehabilitation. Spasticity clinical guidance
3. Suputtitada A, et al. Best Practice Guidelines for the Management of Patients with Post-Stroke Spasticity. 2024. Full text
4. Biering-Sørensen F, et al. Spasticity-assessment: a review. Spinal Cord. 2006. PubMed
5. World Health Organization. Rehabilitation fact sheet. Updated 2024.
6. Khan F, et al. Non-pharmacological interventions for spasticity in adults: an overview of systematic reviews. Cochrane Database of Systematic Reviews. 2017. PubMed
7. Simpson DM, et al. Botulinum neurotoxin for the treatment of spasticity: an evidence-based review. Neurology. 2008. PubMed

Spasticity Information was created as a public service. This page provides general education and should not be relied on for diagnosis, treatment or an individualized medical decision.