What is the difference between spasticity and rigidity?

Spasticity is a velocity-dependent increase in muscle tone from upper motor neuron lesions, meaning resistance rises with faster stretch, whereas rigidity is velocity-independent and characteristic of certain basal ganglia disorders.

Is spasticity always harmful?

Not necessarily; increased tone can sometimes support posture or transfers, so management is goal-directed and targets the spasticity that interferes with comfort, care, or function rather than abolishing tone entirely.

Spasticity Management

Spasticity is a velocity-dependent increase in muscle tone resulting from upper motor neuron lesions, and its management is a core concern in rehabilitation. Management spans assessment of tone and function, physical and rehabilitative strategies, oral and focal pharmacological options, and procedural approaches, chosen according to the distribution and impact of the spasticity.

Definition

Spasticity is a motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex as one component of the upper motor neuron syndrome.

Scope

This topic covers the definition and assessment of spasticity and the categories of management used in rehabilitation, framed as reference knowledge. It does not provide dosing, individualized treatment plans, or procedural instructions.

Core questions

How is spasticity defined and distinguished from other forms of hypertonia?
How is muscle tone and its functional impact assessed?
What categories of management exist, from physical approaches to focal and systemic treatments?
When is spasticity an impairment to treat versus a feature that supports function?

Key concepts

Upper motor neuron syndrome
Velocity-dependent hypertonia
Stretch reflex hyperexcitability
Modified Ashworth Scale
Focal versus generalized spasticity
Botulinum neurotoxin (focal treatment)
Goal-directed management

Mechanisms

Spasticity is one component of the upper motor neuron syndrome and reflects loss of descending inhibitory control after lesions of the brain or spinal cord, leading to hyperexcitable stretch reflexes and a velocity-dependent rise in tone (Lance, 1980). Over time, secondary changes in muscle and connective tissue can add a non-reflexive, biomechanical contribution to stiffness. Management is mechanism- and goal-oriented: rehabilitation and stretching address tone and contracture prevention, focal chemodenervation targets specific overactive muscles, and systemic agents act more diffusely. Associated discomfort and pain can accompany spasticity and may involve central sensitization in some presentations (Woolf, 2011).

Clinical relevance

Spasticity management is central to rehabilitation after stroke, spinal cord injury, multiple sclerosis, and cerebral palsy, where it can affect comfort, posture, hygiene, and function. This entry describes the categories and rationale of management as reference material and does not provide individualized treatment or dosing guidance.

Epidemiology

Spasticity is common after upper motor neuron injury, affecting a substantial proportion of stroke and spinal cord injury survivors and most people with conditions such as cerebral palsy and progressive multiple sclerosis, though prevalence estimates vary with the population and assessment method.

Evidence & guidelines

An American Academy of Neurology practice guideline update reviewed the evidence for botulinum neurotoxin in adult spasticity and other indications, finding support for its use in focal spasticity (Simpson et al., 2016). The conceptual definition by Lance remains the standard reference for what spasticity is (Lance, 1980).

History

James Lance's 1980 symposium synopsis provided the enduring definition of spasticity as a velocity-dependent increase in tonic stretch reflexes within the upper motor neuron syndrome (Lance, 1980). Management evolved from physical therapy and systemic agents toward the addition of focal chemodenervation, with botulinum neurotoxin becoming a mainstay for focal spasticity supported by later guideline review (Simpson et al., 2016).

Debates

When should spasticity be treated?: Because increased tone can sometimes aid standing or transfers, management is goal-directed and selective rather than aimed at eliminating all spasticity, and deciding when intervention helps versus harms function remains a clinical judgement.

Key figures

James W. Lance
David M. Simpson
Robert R. Young

Seminal works

lance-1980
simpson-2016

Frequently asked questions

What is the difference between spasticity and rigidity?: Spasticity is a velocity-dependent increase in muscle tone from upper motor neuron lesions, meaning resistance rises with faster stretch, whereas rigidity is velocity-independent and characteristic of certain basal ganglia disorders.
Is spasticity always harmful?: Not necessarily; increased tone can sometimes support posture or transfers, so management is goal-directed and targets the spasticity that interferes with comfort, care, or function rather than abolishing tone entirely.