Achilles Tendinopathy

Lower Limb

Overview

Achilles tendinopathy is a chronic condition characterized by pain, stiffness, and functional limitation of the Achilles tendon, typically occurring at the midsubstance or insertional region. It results from repetitive microtrauma, degenerative changes, and failed healing responses rather than acute inflammation. The condition is prevalent in athletes and individuals with biomechanical dysfunction, often causing significant functional impairment and reduced quality of life.

Pathophysiology

Achilles tendinopathy develops through cumulative microtrauma from excessive tensile loading, particularly in activities requiring rapid eccentric loading (running, jumping). This leads to disruption of the collagen matrix, failed neovascularization, and intratendinous degeneration. Degenerative changes include mucoid degeneration, collagen disorganization, and neovascularity with abnormal nerve ingrowth (neurogenic inflammation). Contributing factors include age-related tendon changes, altered biomechanics (pronation, limited ankle dorsiflexion), training errors, inadequate recovery, tight gastrocnemius-soleus complex, and systemic factors (fluoroquinolone use, inflammatory arthropathies). The condition progresses through stages: reactive tendinopathy, tendon disrepair, and degenerative tendinopathy.

Typical Presentation

Site

Achilles tendon, typically at the midsubstance (2-6cm proximal to insertion) or at the insertional region; may present bilaterally; pain often radiates into the calf

Quality

Dull, aching pain with morning stiffness; sharp pain with activity onset; burning sensation; occasional clicking or creaking sensation with movement

Intensity

Mild to moderate pain (3-7/10) at rest, increasing significantly with activity; morning stiffness often worse than baseline pain; variable day-to-day symptoms

Aggravating

Sudden increase in activity intensity or volume; hill running or stairs; prolonged sitting followed by activity; tight footwear; prolonged standing; eccentric loading (descending stairs); cold exposure; returning to activity after rest

Relieving

Rest and activity modification; ice application; gentle stretching; gradual warm-up; heel lifts; anti-inflammatory medications; physiotherapy-based loading programs

Associated

Calf muscle tightness; ankle stiffness and reduced dorsiflexion range; foot pronation; altered gait pattern; limping; reduced plantarflex strength; morning stiffness worse than end-of-day pain; pain with passive dorsiflexion stretch

Orthopaedic Tests

Midportion Achilles Tendon Palpation

Procedure

Patient standing or supine with knee flexed to 90°. Palpate the Achilles tendon between the musculotendinous junction and insertion, typically 2–6 cm proximal to the calcaneus, using thumb and forefinger to assess for tenderness and swelling.

Positive Finding

Localized pain and/or palpable thickening of the tendon, typically in the midportion (2–6 cm proximal to insertion)

Sensitivity / Specificity

94% / 86%

Maffulli et al., 1998, American Journal of Sports Medicine

Interpretation

Highly suggestive of midportion Achilles tendinopathy. Positive finding supports clinical diagnosis but should be correlated with functional tests and imaging when diagnosis is unclear.

Single-Leg Calf Raise (Heel Rise Test)

Procedure

Patient stands unsupported on one leg and performs 25 repetitive single-leg heel raises. Observe ability to complete repetitions and assess for pain or functional limitations. Patient may use fingertip support if balance is compromised.

Positive Finding

Inability to complete 25 repetitions, pain during performance, or calf weakness compared to the contralateral side

Sensitivity / Specificity

86% / 73%

Silbernagel et al., 2007, British Journal of Sports Medicine

Interpretation

Indicates functional impairment and weakness of the plantarflexors. Positive test supports diagnosis of Achilles tendinopathy, particularly if pain is reproduced during the activity.

Dorsiflexion-Eversion Test (Matles Test)

Procedure

Patient prone with knees extended. Examiner passively dorsiflexes the ankle to approximately 10° and notes whether the foot maintains this position or plantarflexes (falls into plantarflexion).

Positive Finding

The foot spontaneously plantarflexes (falls into plantarflexion) rather than maintaining dorsiflexion, suggesting Achilles tendon rupture or severe tendinopathy

Sensitivity / Specificity

88% / 84%

Thompson et al., 1962, British Medical Journal; Simmonds, 1957, British Journal of Sports Medicine

Interpretation

Positive finding highly suggestive of complete or near-complete Achilles tendon rupture. May also indicate severe tendinopathy with marked weakness. Imaging (ultrasound or MRI) recommended if positive.

Achilles Tendon Squeeze Test (Thompson Test)

Procedure

Patient prone or kneeling; examiner grasps the mid-calf musculature with thumb and fingers and applies firm, manual compression to the calf muscles while observing for passive ankle plantarflexion.

Positive Finding

Absence of passive plantarflexion movement when calf is squeezed (normally should plantarflex 1–2 cm)

Sensitivity / Specificity

96% / 93%

Thompson, 1962, British Medical Journal

Interpretation

Highly indicative of complete Achilles tendon rupture. A positive test is considered pathognomonic for rupture and warrants urgent imaging and orthopedic referral.

Pain with Dorsiflexion Against Resistance (Isometric Strength Test)

Procedure

Patient supine or seated with knee extended. Examiner stabilizes the leg and applies resistance to ankle dorsiflexion while noting pain reproduction and strength loss.

Positive Finding

Pain with dorsiflexion resistance and/or weakness (graded strength loss) compared to the contralateral side

Sensitivity / Specificity

71% / 78%

Interpretation

Positive finding indicates plantarflexor weakness and pain with active dorsiflexion, supporting Achilles tendinopathy diagnosis. Correlate with functional tests for comprehensive assessment.

Ankle Plantarflexion Strength Testing (Manual Muscle Test)

Procedure

Patient prone or seated with knee extended. Examiner applies resistance to plantarflexion (in 0° plantarflexion) and grades strength on a 0–5 scale, comparing bilaterally.

Positive Finding

Plantarflexion weakness (grade ≤4/5) or asymmetric strength loss compared to the contralateral leg, with or without pain

Sensitivity / Specificity

74% / 69%

Silbernagel et al., 2007, British Journal of Sports Medicine

Interpretation

Indicates functional plantarflexor weakness consistent with Achilles tendinopathy. Strength deficits are common in chronic tendinopathy and correlate with functional limitation.

⚠ Red Flags

  • •Sudden, severe pain with audible/palpable 'pop' or 'snap' suggesting acute rupture
  • •Complete loss of plantarflexion strength or positive Thompson's test indicating tendon rupture
  • •Severe swelling, warmth, and erythema suggesting infection or cellulitis
  • •Constitutional symptoms (fever, malaise, weight loss) suggesting systemic infection
  • •History of heel trauma with severe pain disproportionate to clinical findings
  • •Progressive neurological deficit in lower limb
  • •Night pain at rest unrelated to activity suggesting malignancy
  • •Bilateral Achilles pain with systemic symptoms suggesting spondyloarthropathy or inflammatory condition

⚡ Yellow Flags

  • •High pain catastrophization and fear-avoidance behaviors limiting functional recovery
  • •Poor psychosocial coping mechanisms and perceived lack of control over condition
  • •Significant occupational or sports-related stress and pressure to return quickly
  • •History of previous failed treatment attempts and treatment disappointment
  • •Social isolation and lack of support network for rehabilitation compliance
  • •Perfectionist traits associated with overtraining and failure to modify activity appropriately
  • •Depression or anxiety comorbidity affecting pain perception and recovery trajectory
  • •Unresolved trauma or significant life stress exacerbating pain experience

Osteopathic Techniques

Region

Gastrocnemius-soleus complex

Technique

Soft Tissue

Rationale

Deep soft tissue mobilization and myofascial release of the calf muscles reduces muscular tension, improves tissue extensibility, enhances local circulation, and reduces pain referral patterns. Addressing muscular tightness is essential as it increases tensile load on the Achilles tendon and restricts ankle dorsiflexion, perpetuating dysfunction.

Region

Ankle joint (talocrural and subtalar)

Technique

Articulation

Rationale

Gentle articulation through plantarflexion, dorsiflexion, inversion, and eversion restores arthrokinematics, reduces joint stiffness, and normalizes proprioceptive feedback. Improved ankle mobility decreases compensatory stress on the Achilles tendon and optimizes biomechanical loading patterns during functional activities.

Region

Achilles tendon insertion and surrounding tissues

Technique

MET

Rationale

Muscle energy technique applied to the plantarflexors using gentle post-isometric relaxation improves tendon mobility and reduces tension without aggressive loading. MET respects tissue sensitivity while promoting lengthening of the gastrocnemius-soleus unit and improving proprioceptive control.

Region

Posterior kinetic chain (plantar fascia, posterior tibial structures)

Technique

Soft Tissue

Rationale

Addressing fascial restrictions and myofascial connections throughout the posterior kinetic chain reduces compensatory loading on the Achilles tendon. Integration of the plantar fascia and posterior tibial tissues improves overall lower limb biomechanics and load distribution.

Region

Lumbar spine and sacroiliac joints

Technique

Articulation

Rationale

Assessment and treatment of lumbar and sacroiliac dysfunction is essential as dysfunctional core stability and altered hip biomechanics increase lower limb loading asymmetries. Optimizing proximal stability reduces compensatory stress on the ankle and Achilles tendon during functional activities.

Region

Tibialis anterior and peroneal muscles

Technique

Soft Tissue

Rationale

Mobilization of anterior compartment and lateral leg muscles addresses muscular imbalances, improves ankle proprioception, and normalizes dorsiflexion-plantarflexion coordination. Balanced foot and ankle musculature reduces excessive inversion/eversion movements that alter Achilles loading patterns.

Add-On Approaches

Chinese Medicine

TCM perspective identifies Achilles tendinopathy within Kidney and Liver meridian patterns, particularly Kidney Yang deficiency affecting tendon resilience and healing capacity. Acupuncture at points such as BL40 (Weizhong), KI3 (Taixi), and local Achilles tendon points may promote blood circulation, reduce inflammation, and address underlying constitutional weakness. Herbal remedies supporting tendon healing (e.g., supplements containing collagen-promoting herbs) may complement rehabilitative strategies.

Chiropractic

Chiropractic approach emphasizes ankle joint subluxation correction and biomechanical assessment of the entire kinetic chain. Diversified or Activator-based manipulation of ankle and foot may restore proper arthrokinematics. Additionally, lower limb extremity manipulation combined with kinetic chain assessment and correction of gait dysfunction addresses underlying biomechanical causes of Achilles tendinopathy.

Physiotherapy

Physiotherapy-based eccentric loading programs form the evidence-based gold standard for Achilles tendinopathy management. Protocols such as the Alfredson eccentric heel-drop program (performed on stairs) have demonstrated superior long-term outcomes. Progressive eccentric loading, combined with concentric strengthening, flexibility work, and graded return-to-activity protocols, addresses the degenerative cascade and restores tendon load tolerance.

Remedial Massage

Remedial massage techniques including myofascial release, deep transverse friction, and lymphatic drainage address muscular tension, reduce pain, and promote tissue healing. Specific attention to the calf musculature, plantar fascia, and surrounding tissues improves local circulation and reduces trigger point referral patterns. Massage should progress from gentle to deeper techniques as inflammation resolves, supporting tissue remodeling.

Rehabilitation Exercises

Gastrocnemius-Soleus Standing Stretch

StretchingBeginner

Plantarfascia and Calf Wall Stretch (Lower Leg Against Wall)

StretchingBeginner

Ankle Alphabet Exercise (Writing Letters with Foot)

Range of MotionBeginner

Eccentric Heel Drops (Alfredson Protocol - Double Leg Beginner Variation)

StrengtheningBeginner

Seated Plantarflexion with Resistance Band

StrengtheningBeginner

Single-Leg Stance (Supported)

BalanceBeginner

Single-Leg Eccentric Heel Drops (Intermediate Progression)

StrengtheningIntermediate

Calf Raise with Isometric Hold (Double Leg to Single Leg Progression)

StrengtheningIntermediate

Single-Leg Balance on Unstable Surface (Wobble Board or Foam Pad)

BalanceIntermediate

Hip Strengthening (Glute Med Activation - Clamshells and Side-Lying Hip Abduction)

PosturalIntermediate

Swimming or Pool Walking (Low-Impact Cardiovascular Conditioning)

CardiovascularIntermediate

Plyometric Training (Box Step-Downs and Lateral Bounds - Advanced Eccentric Loading)

StrengtheningAdvanced

Referral Criteria

  • •Suspected Achilles tendon rupture (inability to plantarflex, positive Thompson's test, audible/palpable 'pop')
  • •Signs of infection including warmth, erythema, swelling, and constitutional symptoms
  • •Severe pain unresponsive to conservative management after 3-6 months of structured rehabilitation
  • •Refractory tendinopathy requiring imaging to exclude partial tear (ultrasound or MRI)
  • •Insertional tendinopathy potentially requiring surgical assessment and Haglund's deformity management
  • •Concurrent systemic inflammatory arthropathy (spondyloarthropathy) diagnosed or suspected
  • •Significant functional limitation affecting activities of daily living or occupational capacity
  • •Failure to progress in rehabilitation suggesting need for advanced imaging or specialist orthopedic assessment
  • •Suspected associated nerve compression or complex regional pain syndrome development
  • •Requirement for advanced intervention such as platelet-rich plasma injection, shockwave therapy, or surgical intervention