What causes toes to bend upwards due to muscle tension?

Toes Bending Upwards Due to Muscle Tension

Toes that bend upwards are most commonly caused by muscle imbalances between the intrinsic and extrinsic foot muscles, leading to deformities such as hammertoes or claw toes, where the proximal interphalangeal joint flexes and the metatarsophalangeal joint hyperextends. 1

Primary Causes of Upward Toe Bending

Muscle Imbalance Mechanism

• Imbalance between intrinsic and extrinsic muscle function across the interphalangeal and metatarsophalangeal joints is the fundamental cause of fixed toe deformities 1
• The intrinsic foot muscles normally stabilize the foot and control toe position, but when weakened or dysfunctional, extrinsic muscles dominate and pull toes into abnormal positions 2
• Dorsal contracture at the metatarsophalangeal joint causes the toe to elevate upward, often requiring extensor tendon lengthening for correction 1

Specific Deformity Patterns

• Hammertoe deformity presents with the proximal interphalangeal joint in fixed flexion while the metatarsophalangeal joint hyperextends, creating an upward appearance of the toe 1
• The long extensor tendon can become contracted dorsally, pulling the toe upward at the metatarsophalangeal joint 1
• Collateral ligament tightness at the metatarsal neck can contribute to angular deformities and upward positioning 1

Contributing Factors

Footwear and Pressure

• Inappropriate footwear with narrow toe boxes or inadequate depth increases pressure on toe deformities and exacerbates muscle tension 3
• Shoes that compress the forefoot force toes into abnormal positions over time 3

Neurological Conditions

• Peripheral neuropathy (particularly in diabetes) affects muscle balance and can lead to foot deformities including upward toe positioning 3
• Loss of protective sensation allows deformities to progress without pain feedback 3

Structural Changes

• Elevated plantar pressures from foot deformities create compensatory muscle tension 3
• Bony prominences at the metatarsal heads alter weight distribution and muscle function 3

Clinical Assessment Priorities

Key Examination Findings

• Assess whether the deformity is flexible or fixed by attempting passive correction—flexible deformities respond to conservative treatment while fixed deformities may require surgical intervention 1
• Evaluate for dorsal contracture by checking if the toe can be manually brought down to neutral position 1
• Examine for calluses, pre-ulcerative lesions, or skin breakdown on the apex or distal toe, which indicate excessive pressure from the deformity 3

Associated Risk Factors

• Check for loss of protective sensation using 10-g monofilament testing, as neuropathy commonly coexists with toe deformities 3
• Assess pedal pulses and vascular status, particularly in patients with diabetes or peripheral arterial disease 3, 4

Management Approach

Conservative Treatment (First-Line)

• Wide toe-box shoes with soft uppers to accommodate the deformity and reduce pressure on elevated toes 1
• Padding of bony prominences to prevent skin breakdown 1
• Toe silicone or semi-rigid orthotic devices to help reduce pressure and potentially improve alignment in flexible deformities 3
• Stretching exercises and shoe modifications should be attempted before considering surgical options 1

Surgical Intervention Indications

• Digital flexor tenotomy is recommended for non-rigid hammertoes with nail changes, excess callus, or pre-ulcerative lesions when conservative treatment fails 3
• Proximal interphalangeal joint arthrodesis provides definitive correction for fixed deformities with pain relief in up to 92% of patients 1
• Surgery should only be pursued after exhausting conservative measures including shoe modifications and orthotic devices 1

Special Considerations for High-Risk Patients

• In patients with diabetes and foot deformities, prescribe extra-depth shoes, custom-made footwear, or custom-made insoles to prevent ulceration 3
• Daily foot inspection is critical for patients with neuropathy to identify early signs of skin breakdown from toe deformities 3
• Interprofessional care involving podiatry is recommended for patients with significant deformities and diabetes 3

Common Pitfalls to Avoid

• Do not ignore flexible deformities in early stages—conservative interventions are most effective before contractures become fixed 1, 5
• Avoid excessive bone resection during surgical correction, as this creates cosmetically undesirable short toes 1
• Do not overlook vascular assessment in patients with toe deformities, particularly those with diabetes, as ischemia significantly impacts healing 4
• Ensure adequate bone resection at the proximal interphalangeal joint during arthrodesis to prevent vascular compromise from tension 1