The role of the Achilles tendon is to store and release elastic energy in order to Plantarflex the foot. Plantarflexion is the “pushoff” movement of the foot and ankle in both walking and running. It achieves this through its connection to the calf muscle (gastrocneius and soleus). The Achilles tendon along with the calf muscle also has an important role in absorbing impact forces in runners. What is a tendon? Tendons are defined by being the connection between bone and muscle. They are a structure made up by tight bundles of collagen fibres with very little protein or moisture content to optimise tensile forces (stretch force from one insertion point to the other) along their line of pull. The Achilles tendon is the largest of all tendons in the body and is largely responsible for our ability to walk and especially run at speed. The elastic properties in the tissue allow us to become efficient in these movements and minimise energy expenditure since the stretch and subsequent release of this elastic energy does not rely on the bodies ability to form ATP (energy molecules used by muscles). It works like stretching and releasing an elastic band.Tendons are better equipped to take slow heavy loads than those with increased speed. Tendon pathology The Achilles tendon is a common source of pain and dysfunction, especially in active people and we see many people in clinic with these complaints. Those involved in running hobbies make up the majority of these patients. The cause of these “pathologies” is always due to changes in “load”. Load can be changed in many ways and increased load may be achieved by:
- Quantity – increased overall load for example a sharp increase in distance or training frequency. Note that after periods of rest from training make individuals vulnerable to tendon pathology if they return to old levels of training without re-building.
- Speed – changing the speed in which exercise is performed, example beginning plyometric exercise or sprint drills. Intensity of training impacts speed of load.
- Type – for example changing shoes to a lower heal or running on a hard surface.
Stages of Pathology Initially when a tendon is put under too much load as described above the tendon reacts and there is a small change in the collagen make up and the tendon shows initial signs of inflammatory repair (tenderness, redness & temperature changes). This phase is commonly referred to as “reactive stage” (Cook & Purdem). This initial stage is easily managed by exercise modification, normally involving correcting the overloading factor, whether be footwear, training intensity, running surface, etc.
Second phaseTendinopathy shows “disrepair” or more significant changes to the collagen bundles. There is infiltration of further proteins, increased water content and the beginning of new blood vessels in the tendon structure. All of these things cause a weakening of the tendon and patients normally present with more acute symptoms affecting exercise habits, a longer history of pain and dysfunction and more palpable tenderness (normally 2cm above the heal). This is a more common presentation in the Physiotherapy clinic.
3rd Phase Achilles Tendon damage is known as “degenerative Phase” and is now thought to be irreversible (Cook and Purdem), i.e. the tendon can never revert back to its original “non-pathalogical” state. In these tendons there is great changes within the collagen bundles, with tight tensile fibres now becoming disorganised, infiltrated by many proteins and water, with large neovascularisation (new blood vessels). The feeling of the tendon becomes thicker, but has less ability to absorb load and recoil, i.e. it loses its ability to act strongly to tensile load (the normal purpose of tendons). Tendons in this state have normally been symptomatic for over 6 weeks and are changing exercise habits and ability. There is normally a palpable and significant thickness change with a prominent lump about 2cm above the heal. Treatment in these cases is discussed below in management. Management of Achilles Tendon Pathology Treatment and management protocols depend on the phase of tendon pathology.
Phase 1 – Goal is to identify what change in load has created the beginning of tendon pathology. It is normally a matter of changing this factor and slowly building in quantity, speed and type of load to achieve full recovery. There is only small periods of hands on Physiotherapy required and the focus is on a good biomechanical assessment. Advanz Therapies are skilled at video analysis with slow motion replay and athlete comparisons. We are especially skilled in running assessment.
Phase 2 – All factors for rehabilitation of phase 1 are pertinent yet there is a need for more objective recording of these factors, E.g. diary taking of training practices for load calculation. Specific Physiotherapy for biomechanical issues is necessary at this phase and normally involves biomechanical video analysis (running, walking, gym activity or what ever is considered the problematic activity), treatment to areas loading the tendon, including calf tightness, ankle stiffness and associated muscle weakness (foot to hip and core). Physiotherapy needs to be very skilfully balanced between patient advice, exercise prescription and hands on treatment. A careful planned progression of training and exercise habits is essential at this phase.
Phase 3 – Similar treatment to phase 3 with a slower progression of activity. Generally there is a need for longer periods of time away from plyometric/speed exercises like running and jumping. There needs to be a focus on restoring tendon (collagen) quality to a point where normal loads can again be re-applied to the tendon. Your Physiotherapist will guide you through this path.
Summary: The degenerative changes to tendons are caused by overloading loads over a period of time and may be due to increased quantity, speed or type of load to the tendon. The degenerative phase of collage/tendon breakdown can be categorised into 3 phases. Each progressive phase requiring longer recovery time and more impact on exercise habits . It is therefore important to seek professional advice ASAP with these conditions so that you can continue doing what you love! Advanz Therapies specialise in this recovery process at what ever stage.