Sesamoiditis

Lower Limb

Overview

Sesamoiditis is inflammation of the sesamoid bones beneath the first metatarsal head in the forefoot, commonly affecting the medial sesamoid. This condition results from repetitive micro-trauma, excessive pressure, or direct injury to these small bones embedded within the flexor hallucis brevis tendon, presenting with localized plantar pain and functional limitation.

Pathophysiology

The sesamoid bones act as a fulcrum for the flexor hallucis brevis tendon, distributing ground reaction forces across the first metatarsophalangeal joint during gait and propulsion. Repetitive stress, altered biomechanics, or direct trauma causes chronic inflammation of the bone, surrounding soft tissues, and the articulating surfaces. This leads to pain, swelling, and potential stress fracture or avascular necrosis if untreated.

Patient Education

Sesamoiditis typically improves with activity modification, proper footwear support, and graduated return to activity; avoiding walking barefoot and high-impact activities during acute phases is essential for recovery.

Typical Presentation

Site

Plantar aspect of the first metatarsal head, localized to the medial or lateral sesamoid; pain may radiate along the medial forefoot

Quality

Sharp, aching, or burning plantar pain with a dull underlying ache; may describe cracking or catching sensations

Intensity

Mild to moderate pain (3-7/10) initially, worsening with activity; intensity increases with weightbearing and push-off activities

Aggravating

Walking barefoot, high-impact activities (running, jumping, dancing), prolonged standing, tight footwear, repetitive forefoot stress, push-off phase of gait

Relieving

Rest, elevation, ice application, supportive footwear with cushioning and metatarsal pads, activity modification, strapping or taping

Associated

Swelling and tenderness over the sesamoid area, pain with dorsiflexion of the great toe, altered gait pattern favoring lateral foot, callus formation, clicking or catching sensation

Orthopaedic Tests

AI

First MTP Dorsiflexion Range

Procedure

Passively extend (dorsiflex) the big toe and compare the range with the other side.

Positive Finding

Pain under the first metatarsal head at end of extension, or reduced range.

Interpretation

Extension stretches the sesamoids forwards and can reproduce sesamoid pain. Pain at the top of the joint with stiffness points more to hallux rigidus.

AI

Sesamoid Palpation

Procedure

Extend the big toe to bring the sesamoids forward, then press directly on each sesamoid under the first metatarsal head. Move the toe gently and check that the tender spot moves with it.

Positive Finding

Focal tenderness over one sesamoid (usually the medial) that moves with the toe.

Interpretation

Supports sesamoiditis. Tenderness that moves with the toe localises it to the sesamoid rather than the metatarsal head. Persistent focal pain after running or jumping may be a sesamoid stress fracture; X-ray or MRI is needed.

AI

Great Toe Extension Stress Test

Procedure

Passively extend the big toe to end of range with the ankle dorsiflexed.

Positive Finding

Pain under the first metatarsal head.

Interpretation

Stretches the sesamoid complex. Not specific: plantar plate and joint problems also hurt in this position.

AI

Resisted Great Toe Flexion

Procedure

Ask the patient to push the big toe down against your finger.

Positive Finding

Pain under the first metatarsal head.

Interpretation

Contraction of flexor hallucis brevis, in whose tendons the sesamoids sit, loads the sesamoids and supports them as the pain source.

AI

First MTP Joint Palpation and Distraction

Procedure

Palpate around the first MTP joint, then gently pull the big toe away from the foot.

Positive Finding

Joint line tenderness that eases with distraction.

Interpretation

Helps separate a joint problem (hallux rigidus, synovitis) from sesamoid pain, which sits under the joint.

Not a diagnostic test

Single-Leg Stance or Weight-Bearing Tolerance Test

Procedure

Ask the patient to stand on the affected leg and rise onto the toes.

Positive Finding

Pain under the first metatarsal head when loading the forefoot.

Interpretation

A functional check that guides offloading (padding, stiff-soled shoes) and return to activity. Not a diagnostic test.

⚠ Red Flags

  • •Acute severe pain with inability to weightbear following trauma
  • •Signs of systemic infection (fever, spreading erythema, lymphadenopathy)
  • •Suspected sesamoid fracture with neurovascular compromise
  • •Progressive neurological symptoms or loss of foot sensation
  • •Unrelenting pain unresponsive to 6-8 weeks conservative management
  • •History of previous sesamoid surgery with recurrent symptoms

⚡ Yellow Flags

  • •High athletic demands with pressure to return to activity prematurely
  • •Perfectionist or overly competitive personality affecting compliance with activity modification
  • •Frequent barefoot walking due to lifestyle choices or cultural practices
  • •History of eating disorders or bone health concerns
  • •Low mood or depression affecting self-management
  • •Poor understanding of condition leading to non-compliance with offloading strategies

Osteopathic Techniques

Region

First metatarsophalangeal joint and sesamoid complex

Technique

Soft TissueAI

Rationale

Soft tissue mobilization to the flexor hallucis brevis, adductor hallucis, and surrounding plantar fascia reduces muscle tension, improves local circulation, and decreases pain without direct pressure on inflamed sesamoids

Region

First metatarsophalangeal joint

Technique

ArticulationAI

Rationale

Gentle passive and active range of motion mobilization maintains joint mobility, promotes synovial nutrition, and prevents stiffness while avoiding aggravating movements that stress the sesamoids

Region

Plantar fascia and forefoot

Technique

FunctionalAI

Rationale

Functional technique addresses the biomechanical relationships of the forefoot, allowing tissues to find positions of ease and promoting self-correction of mechanical dysfunction contributing to sesamoid stress

Region

Midfoot and ankle complex

Technique

METAI

Rationale

Muscle energy techniques to the tibialis anterior, peroneal muscles, and foot intrinsics improve proprioception, balance load distribution, and reduce compensatory stress on the sesamoid complex

Region

Plantar arch and medial foot

Technique

Soft TissueAI

Rationale

Myofascial release techniques address fascial restrictions and trigger points in the plantar intrinsics and abductor hallucis, reducing tension on the sesamoid-bearing structures

Region

Lower leg and foot lymphatics

Technique

LymphaticAI

Rationale

Lymphatic drainage techniques promote resolution of local inflammation and swelling, enhancing healing of the inflamed sesamoid tissues and surrounding structures

Rehabilitation Exercises

Great Toe Dorsiflexion and Plantarflexion - Active

Range of MotionBeginner

Plantar Fascia Stretch - Standing with Towel Roll

StretchingBeginner

Calf Stretch - Lunge Position

StretchingBeginner

Foot Intrinsic Exercises - Towel Scrunching

StrengtheningBeginner

Great Toe Flexion Against Resistance - Seated

StrengtheningIntermediate

Single-Leg Stance on Firm Surface

StrengtheningIntermediate

Proprioceptive Training - Single-Leg Balance on Foam

BalanceIntermediate

Foot Arch Activation - Short Foot Exercise

PosturalBeginner

Calf Raises - Double Leg to Single Leg Progression

StrengtheningIntermediate

Ankle Circles and Mobilization - Seated

Range of MotionBeginner

Heel-Toe Walking - Forward and Backward

BalanceIntermediate

Pool Walking or Swimming - Low-Impact Conditioning

CardiovascularBeginner

Referral Criteria

  • •Suspected sesamoid fracture confirmed on imaging or clinical examination
  • •Symptoms persisting beyond 8-12 weeks despite appropriate conservative management
  • •Significant functional limitation affecting activities of daily living or quality of life
  • •Signs of avascular necrosis or degenerative changes on imaging
  • •Need for advanced imaging (MRI, bone scan) to confirm diagnosis
  • •Consideration of injection therapy or surgical intervention by orthopedic surgeon
  • •Concurrent inflammatory arthropathy or systemic disease contributing to symptoms
  • •Neurological symptoms or suspected nerve compression requiring specialist assessment