Achilles tendinopathy is a frequent disorder among sedentary and recreationally active people as well as the athletic population. Achilles tendinopathy represents between 9 to 15% of the total injuries in runners.
Achilles tendinopathy presents clinically as pain on the Achilles Tendon, with localised inflammation, morning stiffness with pain, and impaired function with activities that involve loading of the tendon, such as walking, running and jumping.
Intrinsic risk factors that can contribute to Achilles Tendinopathy are obesity, lower limb muscle power/strength/endurance, reduced ankle dorsiflexion, foot pronation and alignment, high cholesterol and diabetes. Extrinsic risk factors include sudden changes in training loads and activity levels, footwear and training errors.
Current evidence supports a continuum of tendon pathology that has three stages:
Stage 1: Reactive Tendinopathy
- Short-term adaptive thickening of a portion of the tendon.
- Reduces stress by increasing cross-sectional area or allows adaptation to compression.
- Results from acute overload, usually unaccustomed physical activity.
Stage 2: Tendon Disrepair
- The tendon attempts to repair but an increase in protein results in separation of the collagen and disorganisation of the tendon matrix with new blood vessel and nerve growth.
- These tendons are thick with localised changes in one part of the tendon.
- Results from overload of a stiffer tendon that has less adaptive ability, usually in an older person.
Stage 3: Degenerative Tendinopathy
- Not likely reversible stage of tendon change.
- This stage primarily seen in an older person or younger group with a chronically overloaded tendon.
- Often repeated bouts of tendon pain with increasing tendon load changes.