Can muscle relaxers help with Equinus Contracture of the ankle?

Muscle Relaxants Are Not Effective for Equinus Contracture of the Ankle

Muscle relaxants are not recommended for the treatment of equinus contracture of the ankle as they lack evidence of efficacy and carry significant risks, especially in older adults. 1

Understanding Equinus Contracture

• Equinus contracture is defined as ankle joint dorsiflexion less than 5° with the knee extended, and is linked to many lower extremity biomechanical disorders 2
• This condition can result from shortening within the gastrocnemius-soleus complex and has been associated with increased mechanical strains and foot/ankle pathology 3
• Proper evaluation requires consistent methodology using a goniometer with the subtalar joint in neutral position and midtarsal joint supinated while dorsiflexing the ankle with knee extended 2

Why Muscle Relaxants Are Not Recommended

• Muscle relaxants as a class have no evidence of efficacy in treating equinus contracture 1
• Most muscle relaxants do not directly relax skeletal muscle and have limited evidence for efficacy in chronic musculoskeletal conditions 1
• These medications carry significant risks including anticholinergic effects, sedation, and increased risk of falls, particularly in older adults 1
• Specific muscle relaxants have concerning side effect profiles:
  • Cyclobenzaprine is structurally similar to tricyclic antidepressants with comparable adverse effects 1
  • Methocarbamol can cause drowsiness, dizziness, and cardiovascular effects including hypotension 1
  • Metaxalone is contraindicated in patients with significant hepatic or renal dysfunction 1
  • Orphenadrine has anticholinergic properties that can cause confusion and cardiovascular instability 1

Recommended Approaches for Equinus Contracture

Non-Surgical Management

• Functional treatment approaches are preferred over immobilization for ankle-related conditions 4
• Exercise therapy has shown effectiveness in improving ankle function and preventing recurrent ankle issues 4
• For prevention of ankle contractures in hemiplegic patients, positioning the ankle in maximum dorsiflexion for 30 minutes daily may be beneficial 4
• Resting ankle splints used at night and during assisted standing may be considered for prevention of ankle contracture 4

Orthotic Management

• Ankle-foot orthoses (AFOs) can improve gait in patients with active plantarflexion during the swing phase and may be beneficial in preventing ankle contracture 4
• Functional support through bracing has shown effectiveness in ankle-related conditions 4

Surgical Options

• For cases unresponsive to conservative treatment, surgical options include:
  • Percutaneous Achilles tendon lengthening 5
  • Open gastrocnemius recession 5
  • Endoscopic gastrocnemius recession 5
  • The Baumann procedure (intramuscular lengthening of the gastrocnemius muscle) has shown an average increase in ankle dorsiflexion of 14 degrees with the knee extended 6

Rehabilitation Approaches

• Robotic rehabilitation treatment is emerging as a promising procedure to address equinus contracture before severe contraction develops and surgery becomes necessary 7
• Both stationary and wearable ankle rehabilitation devices may be suitable for treatment 7
• Serial casting or static adjustable splints may be considered to reduce mild to moderate contractures 4

Key Pitfalls to Avoid

• Avoid relying on muscle relaxants as a primary treatment for equinus contracture due to lack of evidence and potential side effects 1
• Do not neglect addressing equinus deformity when treating associated disorders, as comprehensive treatment mandates addressing the underlying equinus 2
• Avoid complete immobilization to prevent muscular atrophy and deconditioning 4
• Recognize that equinus contracture may be either an isolated gastrocnemius or combined (Achilles) contracture, requiring different treatment approaches 3