Flexor and extensor tendinopathies of the ankle joint

Anatomy: flexor and extensor tendons of the foot

Flexor tendons and extensor tendons transfer the force of the lower leg muscles to the foot. They run through solid holding structures (retinacula) on the ankle joint and in narrow tendon sheaths that serve as sliding bearings. Compression and friction are particularly relevant in these bottlenecks under high loads.

• Flexors (medial/plantar): Tibialis posterior (arch stabilization), Flexor hallucis longus (big toe flexor), Flexor digitorum longus (toe flexor)
• Extensors (dorsal): Tibialis anterior (foot lifter), Extensor hallucis longus (big toe extension), Extensor digitorum longus/brevis (toe extension)
• Supporting structures: extensor retinaculum (anterior ankle), flexor retinaculum (medial tarsal tunnel)
• Tendon sheaths: reduce friction, can become inflamed (tenosynovitis) or stick together

Tendinopathy describes a painful tendon disease caused by overloading and structural remodeling processes; Inflammatory parts (tendinitis/peritendinitis) can be particularly a. occur in early phases or with tendon sheath involvement.

What is Flexor/Extensor Tendinopathy?

Flexor/extensor tendinopathy refers to painful changes in the flexor or extensor tendons of the foot/ankle. Typically, there is a mismatch between the load and resilience of the tendon, microscopic fiber disorders, thickening of the tendon and pain when subjected to tension or pressure. Often affected: tibialis anterior (foot dorsiflexor), tibialis posterior (medial, longitudinal arch of the foot), flexor hallucis longus (in runners and dancers) and the extensor tendons on the back of the foot.

• Acute overload-related: often after increased training, new footwear, unfamiliar route or surface
• Chronic-degenerative: persistent overload, misalignment (arch arches/hollow feet), reduced tendon quality

Typical symptoms

• Locally tender tendon along its course (medially on the inner ankle, on the back of the foot/dorsally, rarely laterally)
• Starting pain after rest, improvement with moderate exercise, increasing again with higher exertion
• Swelling, occasionally rubbing/creaking (crepitation) if the tendon sheath is involved
• Pain during active movement against resistance (e.g. raising/lowering the foot, extending/flexing the toes)
• Stress-dependent limitation of the ability to run and jump, climb stairs and walk longer distances

Causes and risk factors

• Stress errors: rapid increase in training, monotonous repetitions, hard surfaces, lack of regeneration
• Shoe/equipment problems: worn or too hard shoes, improper drop, lack of stability
• Foot and leg axes: arched arches (medial overload, tibialis posterior), hollow foot (dorsal increase in tension), leg length difference
• Joint mobility: limited dorsiflexion in the upper ankle joint, shortened calf muscles
• Systemic factors: older age, diabetes mellitus, rheumatism, thyroid disease, smoking
• Medication: rarely fluoroquinolone antibiotics or systemic cortisone therapy as a risk factor
• Previous injuries: distortions, scars/adhesions on tendon sheaths

Differentiation from other causes

• Peroneal tendinopathy (lateral) – different group of tendons, similar symptoms
• Achilles tendon problems (posterior) – different localization
• Ligament irritation or ligament injuries after overloading/kinking
• Bone stress reactions/stress fracture (metatarsalus, tibial edge, talus)
• Nerve constriction (tarsal tunnel syndrome medially; deep peroneal nerve dorsally)
• Anterior ankle impingement, osteoarthritis, osteophyte-related irritation
• Inflammatory systemic diseases, gout (rare, then often acute and very painful)

Diagnostics in practice

The diagnosis is based on a careful clinical examination, functional and stress tests and, if necessary, imaging tests. The aim is to assign the affected tendon, assess the resilience and identify triggering factors.

• Anamnesis: onset of pain, stress profile, shoes, previous illnesses and medications
• Inspection/palpation: tenderness along the tendon path, swelling, crunching
• Function: resistance tests (e.g. foot lift for tibialis anterior), range of motion, arch
• Gait and running analysis, if necessary assessment of the leg axis
• High-resolution ultrasound: tendon thickness, structure, hypervascularization, tendon sheath effusion; dynamic display
• MRI: in case of unclear diagnosis, resistance to therapy or suspicion of partial/complete tear, bone sediment or accompanying pathologies
• X-ray: Axial/misalignment, bony attachments, exclusion of osseous causes

Conservative treatment – ​​stress-oriented first

Conservative measures are usually very effective for tendinopathies. They aim to reduce irritating factors, restore tendon homeostasis and gradually build up load with targeted training.

• Stress control: short-term reduction in pain-provoking activities (e.g. sprints, mountain runs), maintaining basic fitness through alternative stress (cycling, aqua jogging)
• Acute measures: cooling after exercise, temporary anti-inflammatory topical preparations; Oral NSAIDs should only be used for a short period of time and should be considered individually
• Shoe and surface adaptation: sufficient cushioning, stability; If necessary, other lacing on the back of the foot to relieve pressure
• Insoles/Orthoses: for arched arches, relief of the medial tendons (tibialis posterior); Pressure-relieving elements for hollow feet
• Taping/orthosis: temporary guidance/relief, v. a. with everyday or work stress
• Physiotherapy: isometric pain control (early), eccentric-emphasized and later heavy-slow resistance training, mobilization of adjacent joints/soft tissues
• Stretching and mobility work: calf muscles, ankle dorsiflexion, plantar fascia
• Manual/soft tissue techniques: tendon sheath mobilization, gliding exercises – evidence-based supplementary
• Shock wave therapy: can be considered for chronic tendinopathies of individual tendons; Benefit individually

A structured step-by-step program is important: pain ≤ 3/10 under stress is usually tolerable; If the pain intensity is higher, the load should be adjusted. The training plan is tailored to the affected tendon (e.g. big toe focus for the flexor/extensor hallucis, foot drop training for the tibialis anterior).

Targeted injections and regenerative options

If symptoms persist despite consistent conservative therapy, interventional measures can be considered. These are carried out after precise ultrasound diagnostics and with information about opportunities and risks.

• Ultrasound-targeted infiltration into the tendon sheath (not intratendinous): can contribute to short-term inflammation and pain relief in severe tenosynovitis; Carefully weigh the risk-benefit
• Needling/hydrodissection: to release adhesions on the tendon sheath in individual cases
• Platelet-rich plasma (PRP): for chronic, therapy-resistant tendinopathies as an option with heterogeneous evidence; Effect individual, no guarantee of success
• High-volume injection around the tendon: debatable in selected cases; limited evidence

Our approach is conservative. Interventions are only considered after structured training and stress management.

When does an operation make sense?

Surgery is rarely necessary. Indications can include treatment-resistant courses over several months, relevant structural damage (partial/complete tears), pronounced tendon sheath fibrosis or retinaculum problems. The aim is to relieve pressure, debride damaged tissue and restore lubrication.

• Tenosynovectomy/debridement for persistent tenosynovitis/adhesions
• Reconstruction/refixation in the event of a tear or instability (individual technique depending on the tendon)
• Accompanying corrections: e.g. B. Addressing significant misalignments when necessary

Follow-up treatment: functional follow-up treatment with gradual increase in load, physiotherapy and targeted build-up. Healing times vary depending on the findings.

Course and prognosis

• If detected and treated early, symptoms often improve significantly within 6-12 weeks
• In chronic cases, a structured program can take 3-6 months
• Relapse prevention through continued strength and coordination training, appropriate footwear and training control

The individual healing time depends on the tendon involvement, duration of the symptoms, stress profile and accompanying factors. Avoid returning to high intensities too quickly.

Self-help: What you can do yourself

• Adjust load to pain limit; move regularly but in a measured manner
• Cool after exercise, slightly elevated if there is a tendency to swell
• Check/change shoes: enough space on the back of the foot, cushioning sole, stable heel cap
• Vary the surface, reduce shock loads; Intervals instead of continuous stress
• Calf/foot mobilization daily; eccentric exercises according to instructions
• Plan for regeneration: sleep, nutrition, if necessary, nicotine abstinence

Exercises for flexor and extensor tendons

Note: Exercises should be moderately painful at most. If pain provocation persists, reduce stress and obtain instructions.

Sports and work-related aspects

• Running/trail: slow increase in volume (10-15%/week), more soft surfaces; Carefully dose the downhill portions
• Ball sports/stop-and-go: train jumping and landing techniques, prioritize calf strength and foot stability
• Dance/Ballet: Flexor hallucis longus strained – check technique and footwear, specific eccentricities
• Jobs that involve a lot of walking/standing: micro-breaks, soft insoles, temporary orthoses if necessary

When should I seek medical advice?

• Sudden shooting pain with a feeling of tearing, significant loss of function or hematoma
• Rapidly increasing swelling, redness, overheating, fever
• Numbness, tingling, motor weakness
• Persistent pain despite rest and basic therapy for several weeks

Your orthopedic care in Hamburg

In our practice at Dorotheenstraße 48, 22301 Hamburg, you will receive structured diagnostics and conservative therapy for flexor and extensor tendinopathies. We combine modern imaging (especially high-resolution ultrasound) with stress-oriented physiotherapy, individual training planning and – if appropriate – targeted interventions.

Together we set realistic therapy goals, adapt the load structure to everyday life and sport and take factors such as foot position, footwear and previous stress into account. We consistently avoid overtreatment with unnecessary injections or operations.