Physical Therapy Rehabilitation Protocol: Morton's Neuroma

1. Clinical Overview and Pathophysiology

Morton’s neuroma is a painful condition affecting the ball of the foot, most commonly presenting as a perineural fibrosis rather than a true neoplasm. It involves the thickening of the tissue surrounding one of the nerves leading to the toes. While it can occur between any of the metatarsals, it most frequently affects the third common digital plantar nerve located in the third intermetatarsal space (between the third and fourth metatarsal heads).

Pathophysiology: The etiology is typically mechanical. The nerve becomes entrapped or compressed against the deep transverse intermetatarsal ligament. This compression is often exacerbated by excessive pronation, narrow footwear, or hyperextension of the toes (dorsiflexion) during the propulsive phase of gait. Repeated mechanical irritation leads to swelling, endoneurial edema, and eventually fibrosis of the nerve trunk.

Clinical Presentation: Patients report burning pain, paresthesia, or numbness in the forefoot and corresponding toes. A hallmark description is the sensation of "walking on a marble" or a pebble. Clinical testing often reveals a positive Mulder’s sign (a palpable click and reproduction of pain when compressing the metatarsal heads while applying plantar pressure to the interspace).

2. Phase-Based Rehabilitation Timeline

This protocol follows a conservative management approach. The timeline is criterion-based; progression requires meeting specific milestones rather than strictly adhering to weeks.

Phase I: Protection and Acute Symptom Management (Weeks 0-4)

Goals: Reduce inflammation and neurogenic pain, protect the healing nerve tissue, and maintain kinetic chain mobility without aggravating the forefoot.

Clinical Interventions:

• Footwear Modification: This is the single most critical intervention. The patient must switch to shoes with a wide toe box and low heel to decrease compressive forces on the metatarsal heads.
• Metatarsal Pad Placement: Application of a teardrop-shaped metatarsal pad. Crucial Note: The pad must be placed proximal to the metatarsal heads (not directly on them) to spread the metatarsals and offload the interdigital nerve.
• Manual Therapy: Soft tissue mobilization to the gastrocnemius/soleus complex; gentle mobilization of the metatarsals (dorsal/plantar glides) to increase intermetatarsal space.
• Activity Modification: Avoidance of high-impact activities (running, jumping) and positions requiring extreme toe extension.

Phase I Exercises:

• Non-Weight Bearing Gastrocnemius Stretch: Seated towel stretch to improve ankle dorsiflexion without loading the forefoot. Tight calves lead to compensatory forefoot pressures.
• Toe Yoga (Active Dissociation): While seated, attempt to lift the big toe while keeping lesser toes down, and vice versa. This encourages intrinsic motor control without heavy loading.
• Seated Intrinsic Arch Activation (Short Foot): With the foot flat on the floor, attempt to draw the metatarsal heads toward the heel without curling the toes, effectively raising the medial longitudinal arch. Hold for 5 seconds, repeat 10 times.
• Ankle Alphabet: Non-weight bearing AROM to maintain ankle mobility.

Phase II: Progressive Loading and Kinetic Chain Strengthening (Weeks 4-8)

Goals: Correct biomechanical faults (specifically over-pronation), increase load tolerance of the foot intrinsics, and strengthen the proximal kinetic chain (hips/glutes) to reduce distal impact.

Clinical Interventions:

• Gait Retraining: Cueing to reduce over-striding and excessive push-off forces.
• Orthotic Evaluation: If symptoms persist due to arch collapse, custom or semi-custom orthotics with metatarsal support may be indicated.
• Joint Mobilization: Continued grade III/IV mobilizations for talocrural and subtalar joints to ensure adequate dorsiflexion range.

Phase II Exercises:

• Double to Single Leg Heel Raises: Performed on a flat surface. Rise up on two feet, shift weight to the affected side, and slowly lower (eccentric control). Avoid maximum range if it triggers nerve pain.
• Towel Scrunches: Seated or standing. Use toes to scrunch a towel on the floor to strengthen flexor digitorum brevis and longus.
• Clamshells and Side-Lying Hip Abduction: Strengthening the Gluteus Medius is vital to control femoral internal rotation and subsequent subtalar eversion/pronation.
• Single Leg Stance on Foam: Proprioceptive training to improve ankle stability. Maintain arch integrity (Short Foot) during balance tasks.

Phase III: Functional Restoration and Return to Sport (Weeks 8+)

Goals: Restore full plyometric capacity, return to sport-specific drills, and ensure equipment (cleats/shoes) accommodates the foot anatomy.

Phase III Exercises:

• Pogo Jumps: Low-amplitude, double-leg hops focusing on "stiff" ankle mechanics and mid-foot landing.
• Forward and Lateral Lunges:Focus on maintaining a neutral foot tripod (heel, 1st metatarsal, 5th metatarsal) during the deceleration phase.
• Ladder Drills: Agility drills (e.g., Ickey Shuffle) to introduce multi-planar forces to the forefoot.
• Walk-Jog Progression: Interval program initiating on a treadmill or track. 1 minute jog / 3 minutes walk. Progression relies on pain latency (pain should not exceed 3/10 and must resolve within 1 hour post-activity).

3. Return to Play (RTP) Criteria

Return to sport is permitted when the patient demonstrates the ability to handle the specific loads of their activity without exacerbating the neural inflammation. The following criteria must be met:

• Pain-Free ADLs: Patient experiences no pain during daily walking or prolonged standing.
• Full Range of Motion: Ankle dorsiflexion (knee to wall test) is symmetrical, and MTP extension is functional without pain.
• Strength Symmetry: Plantarflexion strength is within 90% of the unaffected limb (measured via single-leg heel raise capacity).
• Palpation: Negative Mulder’s sign or significantly reduced sensitivity compared to initial evaluation.
• Functional Testing: Able to perform a single-leg hop test with adequate stability and no pain upon landing.
• Footwear Compliance: Patient has modified athletic footwear (e.g., wider cleats, stiffer sole to limit MTP extension) to prevent recurrence.