Classification
- Type: Synovial condyloid (biaxial)
- Degrees of freedom: 2 (flexion/extension dominant; some abduction/adduction)
- Region: Forefoot
Articular Surfaces
- Metatarsal head (convex): Large, rounded head of the first metatarsal. Wider transversely than vertically. The plantar surface has two grooves for the sesamoid bones. Covered with hyaline cartilage.
- Proximal phalanx base (concave): A shallow concavity that receives the metatarsal head. Covered with hyaline cartilage.
- Sesamoid bones: Two small bones (medial and lateral) embedded in the plantar plate (thickening of the plantar capsule) beneath the metatarsal head. They increase the mechanical advantage of the flexor hallucis brevis, protect the FHL tendon, and bear significant weight. Sesamoiditis (inflammation) produces localized plantar pain under the first metatarsal head.
Movements and ROM
Extension is the critical functional movement. During the toe-off phase of gait, the first MTP extends to approximately 60°. This extension tightens the plantar fascia via the windlass mechanism — the plantar fascia wraps around the metatarsal head like a windlass, raising the arch and converting the foot into a rigid lever for push-off. Loss of extension (hallux rigidus) disrupts this mechanism and severely impairs gait.
Capsular Pattern
Extension > Flexion
Extension loss is the hallmark of first MTP capsular pathology. In hallux rigidus, extension is progressively lost while flexion is relatively preserved. This pattern directly impairs the toe-off phase of gait.
Resting Position
- 10° extension (slight dorsiflexion)
- Maximum capsular volume
Close-Packed Position
- Full extension
- Maximum congruence, windlass mechanism engaged, plantar fascia taut
End-Feels
| Movement |
Normal End-Feel |
Type |
| Extension |
Capsular (firm) |
Plantar capsule, plantar plate, FHL tendon, plantar fascia tension. Becomes bony (hard) in hallux rigidus due to dorsal osteophytes. |
| Flexion |
Capsular (firm) |
Dorsal capsule, extensor tendons |
Ligaments
Collateral Ligaments (Medial and Lateral)
- Attachments: Metatarsal head (medial and lateral tubercles) → proximal phalanx base
- Function: Resist valgus and varus stress. The medial collateral is commonly attenuated in hallux valgus (bunion deformity), allowing the great toe to deviate laterally.
Plantar Plate (Plantar Ligament)
- Attachments: Metatarsal neck → proximal phalanx base (plantar surface)
- Function: A thick fibrocartilaginous structure that reinforces the plantar capsule. Contains the sesamoid bones. Resists hyperextension and bears significant compressive load during toe-off. Tears of the plantar plate (turf toe) produce instability and functional loss.
Mobilization Techniques
Hands-on instruction is required. The descriptions below provide clinical reference detail for understanding and supervised practice. They are not a substitute for instructor-led technique training. Correct hand placement, force dosage, and tissue response interpretation require hands-on coaching and feedback.
Convex-Concave Rule at the First MTP Joint
The metatarsal head is
convex and the proximal phalanx base is
concave. Mobilization can move either surface:
- Moving the concave phalanx on the fixed metatarsal (most common): Glide is in the same direction as the restriction
- Moving the convex metatarsal on the fixed phalanx: Glide is in the opposite direction to the restriction
| Restricted Movement |
Glide Direction (moving phalanx) |
Reasoning |
| Extension |
Dorsal (superior) glide of phalanx |
Concave on convex → same direction |
| Flexion |
Plantar (inferior) glide of phalanx |
Concave on convex → same direction |
General Contraindications
- Absolute: Fracture (metatarsal head, proximal phalanx, sesamoid), acute gout flare (the first MTP is the most common gout site — podagra), acute infection, acute turf toe (plantar plate tear)
- Relative: Advanced hallux rigidus with bony end-feel (Grade I–II only; do not force into osteophytes), hallux valgus with MTP instability, significant joint inflammation
Dorsal Phalangeal Glide (for Extension)
Purpose: Restores first MTP extension — the most clinically important mobilization at this joint. Extension loss impairs gait by disrupting the windlass mechanism.
Patient position:
- Supine or seated with the foot accessible
- Forefoot resting on the table or supported
Hand placement:
- Stabilizing hand: Thumb and index finger grip the first metatarsal head firmly, stabilizing it
- Mobilizing hand: Thumb and index finger grip the proximal phalanx of the great toe. Force directed dorsally (superiorly).
Technique execution:
- Apply an oscillatory force directing the proximal phalanx dorsally on the metatarsal head
- Grade I–II: Gentle oscillations for pain modulation in acute hallux rigidus or post-surgical stiffness
- Grade III–IV: Oscillations at end-range extension, into the plantar capsular resistance. In hallux rigidus, the barrier may be bony (dorsal osteophytes) — do not force into a bony end-feel.
- Duration: 30 seconds per set, 3–5 sets
Indications:
- Hallux rigidus (progressive loss of extension with dorsal osteophytes)
- Post-surgical stiffness (bunionectomy, cheilectomy)
- Post-immobilization extension loss
- Functional extension <60° (minimum for normal gait)
Technique notes:
- Bony vs. capsular end-feel distinction is critical. If the end-feel is bony (hard, abrupt), dorsal osteophytes are blocking motion — Grade III–IV into bone is contraindicated and painful. If the end-feel is capsular (firm, yielding), mobilization can improve range.
- Sesamoid mobility: Assess sesamoid glide independently. The sesamoids must glide distally during extension. Restricted sesamoids limit extension even if the MTP capsule is addressed.
- Reassessment: Test great toe extension in weight-bearing (the patient pushes off during gait — observe for toe-off quality).
First MTP Distraction
Purpose: General capsular stretch and pain modulation. Opens the joint space, decompresses arthritic surfaces.
Patient position: Same as above.
Hand placement:
- Stabilize the metatarsal head. Grip the proximal phalanx and apply traction distally along the long axis of the toe.
Technique execution:
- Oscillatory or sustained traction
- Grade I–II: Pain modulation for acute gout recovery or acute MTP inflammation (after the acute phase has resolved)
- Grade III: Capsular stretch
- Duration: 30 seconds, 3–5 sets
Muscles Crossing This Joint
- anatomy/muscles/flexor-hallucis-longus — powerful great toe flexor; the "dancer's muscle"; runs in a groove between the posterior talar processes
- anatomy/muscles/flexor-hallucis-brevis — two bellies attaching to the sesamoid bones; flexes the MTP joint
- anatomy/muscles/extensor-hallucis-longus — extends the MTP and IP joints; also dorsiflexes the ankle
- anatomy/muscles/extensor-hallucis-brevis — extends the MTP joint only
- anatomy/muscles/abductor-hallucis — abducts and flexes; medial arch support; weakened in hallux valgus
- anatomy/muscles/adductor-hallucis — adducts; its oblique and transverse heads support the transverse arch; its contracture contributes to hallux valgus
Conditions Affecting This Joint
- Hallux rigidus — degenerative OA of the first MTP; progressive extension loss; dorsal osteophytes; pain during push-off; the most common arthritic condition of the foot
- Hallux valgus (bunion) — lateral deviation of the great toe with medial prominence of the metatarsal head; medial collateral attenuation, adductor hallucis contracture; pain at the medial eminence
- Gout (podagra) — the first MTP is the most common site for gout; acute inflammatory monoarthritis with severe pain, redness, swelling; caused by urate crystal deposition
- Turf toe — plantar plate sprain from hyperextension; common in athletes on artificial turf; grades I–III; produces instability and pain with push-off
- Sesamoiditis — inflammation or stress fracture of the sesamoid bones; plantar pain directly under the first metatarsal head
Clinical Notes
- Hallux rigidus is the most common arthritic foot condition. It presents as progressive first MTP extension loss with dorsal osteophytes palpable on the metatarsal head. The patient reports difficulty with push-off during walking. Early stages respond well to mobilization (capsular stretching) and rocker-bottom shoes. Advanced stages with bony block may require cheilectomy (removal of dorsal osteophytes) or fusion.
- The windlass mechanism is essential for gait efficiency. During toe-off, first MTP extension winds the plantar fascia around the metatarsal head, raising the medial longitudinal arch and converting the flexible foot into a rigid lever. Loss of first MTP extension disrupts this mechanism — the foot cannot become rigid, push-off is weakened, and compensatory hip, knee, and ankle strategies develop.
- Always screen for gout in acute first MTP inflammation. A patient presenting with sudden-onset severe first MTP pain, redness, swelling, and warmth — especially a male over 40 or a patient taking diuretics — has gout until proven otherwise. Do not mobilize during an acute gout flare. Refer for serum uric acid testing.
Key Takeaways
- First MTP extension (70–90°) is essential for the windlass mechanism and normal gait — loss of extension (hallux rigidus) is the most common arthritic foot condition.
- Capsular pattern extension > flexion — extension loss is the defining restriction; always distinguish capsular (firm) from bony (hard) end-feel before mobilizing.
- The first MTP is the most common gout site — always screen for gout in acute inflammatory presentations before attributing pain to mechanical causes.
