Tendinopathies: Another Alternative
TENDON injuries or tendinopathies of the lower limbs are a constant cause of concern and frustration for athletes and coaches. No matter what level you compete at, they are renowned for being slow to respond to treatment. Rest is a treatment option that is frequently prescribed, which can mean a significant loss of training and competition time for the affected athlete, which is not an ideal situation.
In this brief article I want to highlight two eccentric strength exercises, which according to current research have been shown to have a positive effect on the treatment and prevention of lower limb tendinopathies. I will also briefly discuss the structure of tendons and the current thinking on the causes of tendinopathies. Hopefully this information may offer athletes and coaches alike, another treatment option when dealing with this problem.
Tendons
A tendon is a band of connective tissue. A tendon`s primary role is to transform the muscular force produced by the muscle into mechanical energy, by transferring muscular force to the bone during concentric muscle actions. They also play a key role in the stretch shortening cycle. During eccentric muscle actions, where the muscle is lengthened by an external force while it is actively contracting, the tendons role is to store the elastic energy created by this lengthening of the muscle. So it can then be released to enhance the muscular force produced by the subsequent concentric muscle action. This is done in conjunction with transferring the muscular force to the bone.
Tendons are typically subjected to high loads, especially in sport. Tendons like muscle adapt to the load placed upon them. 1The main component of tendons are collagen fibres. In healthy, normal tendons the collagen fibres form tight, neat bundles in a layered structure with the fibres arranged parallel to each other. The collagen bundles are arranged in series. In that alignment the collagen fibres have most tensile strength. Appropriate loading of the tendon causes increased growth of its cross sectional area which leads to increased tensile strength and a stronger tendon overall.
Tendinopathies usually result from failed healing of the tendon due to the excessive strain placed on it; as tendons do not adapt to the forces placed upon them as fast as muscle tissue. Although no definite cause and effect has been found for tendinopathies; it has been shown they can be caused by a sudden increase in volume, intensity or 2simply repetitive excessive mechanical loading in an athlete`s training program. Thus tendinopathies can be termed over-use injuries. Too much, too soon, too often is a trap many athletes fall into, especially in sports where accelerations, decelerations, changes of direction and jumping are common. All of these actions place a heavy eccentric load on the tendons involved.
Tendinosis is the term coined for the group of the tendinopathies where there is no inflammation even though the tendon may appear to be thickened. It is a chronic tendinopathy which may or may not be painful. Tendinosis leads to tendon degeneration, reduction in tensile strength and often pain and frustration for the affected athlete. In this state the collagen fibres lose their highly organised structure, becoming a lot more disorganised and lose some of their tensile strength as a result of the disorganised structure. This can leave an athlete more susceptible to more serious tendon injury such as a rupture. When chronic, tendinosis can be a very difficult condition to cure; however eccentric strengthening has been shown to help return; a once affected tendon to its normal structure 4.
Achilles Tendon Eccentric Strengthening Exercise
Achilles tendinopathies affect many athletes, with a yearly incidence among runners of between 24 - 64% 7. In middle distance and long distance athlete the yearly incidence is 7 – 11%.
Eccentric Calf Raise: To start the athlete should stand on a step with straight legs and trunk fully extended, then raise up on their toes so that all their bodyweight is on their forefeet. Next using the injured leg only lower the heel slowly, as far as possible until a stretch is felt in the calf muscle and/or Achilles tendon. At that point the athlete should return to the starting position using their non- injured leg to help return i.e. one leg down, two legs up.
To emphasise the load on the calf muscle the exercise can also be done with the knee flexed as in Fig 1 (C)
The athlete should aim to do 3 sets of 15 reps twice a day. This should be continued for 12 weeks according to available research 3.A certain level of pain is to be expected during the exercise, it should not be so severe though as to be unbearable. A certain amount of muscle soreness is to be expected from this exercise for the first 7 – 10 days as it is heavily eccentric. So the athlete is advised to progress slowly during the first week so as not to increase their symptoms of pain and morning stiffness. Start with 1 set of 15 twice a day and progress from there.
When the athlete can do the above exercise without pain, then the exercise needs to be progressed by adding more weight. This can be done in 2 ways. You can wear a weighted back pack during the exercise, increasing the weight in 5kg increments; remember though to keep the trunk fully extended and a flat lower back. You can also use a Smith Machine in the gym if heavier weights are needed, again increasing the weight by 5kg increments.
