Spasticity After Stroke: Management & Physiotherapy

Introduction to Post-Stroke Spasticity

Following a stroke, the brain's ability to communicate with muscles throughout the body can be severely disrupted. As recovery progresses, many stroke survivors begin to notice that their limbs feel abnormally stiff, tight, or resistant to movement. This condition is known as spasticity, and it is a hallmark symptom of an upper motor neuron lesion. Spasticity affects up to 40% of stroke survivors, frequently presenting in the upper limb flexor muscles (clenched fist, bent elbow) or lower limb extensor muscles (stiff knee, plantarflexed ankle).

Left unmanaged, chronic muscle tightness can lead to painful muscle spasms, severe joint contractures, and difficulty with basic activities of daily living (ADLs) such as dressing, eating, or walking. Developing a comprehensive plan for spasticity management stroke recovery involves a tight collaboration between neurologists, rehabilitation physicians, and clinical physiotherapy providers.

The Clinical Definition and Pathophysiology of Spasticity

In clinical medicine, spasticity is formally defined as a velocity-dependent increase in muscle tone. This means that the faster a therapist attempts to stretch the affected muscle, the greater the resistance they will encounter.

Why Does Spasticity Occur?

When an ischemic or hemorrhagic stroke damages the motor pathways in the brain (such as the corticospinal tract), descending inhibitory signals to the spinal cord are lost. This results in the hyperexcitability of the stretch reflex arc. Normally, when a muscle is stretched, a signal is sent to the spinal cord, which responds by contracting the muscle slightly to prevent tearing. In healthy individuals, the brain dampens this reflex. Without descending brain inhibition, the reflex loop runs unchecked, causing the muscle to remain in a state of continuous contraction.

Key Clinical Features

• Hypertonia: Increased resting muscle tension.
• Clonus: Rhythmic, involuntary muscle contractions and relaxations, commonly seen at the ankle when the foot is flexed upward quickly.
• Spastic Co-contraction: Simultaneous firing of opposing muscle groups (e.g., biceps and triceps contracting at the same time), which severely restricts joint movement.
• Contracture: Permanent shortening of the muscle, tendon, or joint capsule, locking the joint into a fixed, non-functional position.

Multidisciplinary Spasticity Management Framework

Spasticity is managed using a progressive treatment pyramid, starting with conservative physical interventions and moving to pharmacological or surgical options for severe cases.

1. Physiotherapy and Physical Interventions

Physical therapy forms the foundation of all spasticity management. The goals are to maintain muscle length, prevent joint contractures, and improve active movement.

• Prolonged Stretching and Weight-Bearing: Static stretching held for several minutes, or standing in a tilt-table or standing frame, provides prolonged stretch to the calf and hamstring muscles. This temporary downregulates the hyperactive stretch reflexes.
• Splinting and Orthotics: Custom splints, casts, or Ankle-Foot Orthoses (AFOs) hold the affected limbs in functional alignment, preventing muscles from shortening during sleep or periods of inactivity.
• Antagonist Muscle Strengthening: Spasticity often causes the opposing muscles to become weak and stretched out. For instance, if the biceps are spastic, the triceps (the antagonist muscle) will be weak. Strengthening the triceps helps actively open the elbow joint.
• Functional Electrical Stimulation (FES): Applying mild electrical stimulation to the weak antagonist muscles helps them contract and dynamically stretch the spastic muscle.

2. Pharmacological Treatments

• Botulinum Toxin (Botox) Injections: Botox is injected directly into the spastic muscle under electromyography (EMG) or ultrasound guidance. It blocks the release of acetylcholine at the neuromuscular junction, temporarily paralyzing the hyperactive muscle fibers for 3 to 4 months. This creates a critical therapeutic window for physiotherapists to stretch and strengthen the limb.
• Systemic Oral Medications: Oral muscle relaxants such as Baclofen, Tizanidine, or Dantrolene are used to manage generalized spasticity, though they can carry side effects like systemic drowsiness.
• Intrathecal Baclofen Pump (ITB): For severe, generalized lower-limb spasticity, a pump is surgically implanted to deliver Baclofen directly into the spinal fluid, minimizing systemic side effects.

Comparison of Spasticity Management Modalities

| Intervention | Mechanism of Action | Best Suited For | Key Side Effects / Considerations | | :--- | :--- | :--- | :--- | | Prolonged Stretching | Mechanical elongation of fibers, reflex dampening | All severity levels, preventing contractures | Requires consistent daily compliance | | Custom Splinting (AFO/Splints) | Static positional holding to maintain joint angle | Preventing fixed contractures, assisting gait | Risk of skin breakdown if poorly fitted | | Botox Injections | Chemical denervation at the neuromuscular junction | Focal spasticity (e.g., clenched fist, foot drop) | Temporary effect (lasts 3–4 months) | | Oral Medications (Baclofen) | Central nervous system downregulation | Generalized, multi-limb spasticity | Drowsiness, fatigue, muscle weakness | | Intrathecal Baclofen Pump | Direct cerebrospinal fluid delivery of relaxant | Severe, intractable lower limb spasticity | Surgical risks, pump malfunction, refill compliance |

Diagnostic Grading of Spasticity

Clinicians measure the severity of spasticity using the Modified Ashworth Scale (MAS), which grades the resistance encountered during passive joint movement:

• Grade 0: No increase in muscle tone.
• Grade 1: Slight increase in tone, giving a catch and release at the end of the range of motion.
• Grade 1+: Slight increase in tone, manifest by a catch, followed by minimal resistance throughout the remainder (less than half) of the ROM.
• Grade 2: More marked increase in muscle tone through most of the ROM, but the affected part is easily moved.
• Grade 3: Considerable increase in muscle tone; passive movement is difficult.
• Grade 4: Affected part is rigid in flexion or extension.