Assessment and evaluation
Achilles tendinosis occurs in clients involved in repetitive activities or who have recently increased their activity level prior to the onset of symptoms. Generally, symptoms come on gradually. The collagen degeneration of tendinosis may be present for some time with no symptoms, so a problem may exist well before the client is aware of it. A thorough history of the client’s activities and medications will help identify the nature of this injury.

Visible enlargement of the tendon compared to the unaffected side may be apparent if tendinosis or peritenonitis are present. The size increase is due to fibrous build-up within the tendon or between the tendon and its paratenon. Nodules or a roughened surface may be palpable on the tendon along its length. While the whole tendon may be tender to palpation, the nodules are more common several centimeters proximal to the tendon insertion on the calcaneus. If peritenonitis is present, there may be some warmth in the tendon due to inflammatory activity. Crepitation (grinding or grating sensations) may also be felt in the tendon as it moves through its range of motion.

Depending on the severity of the tendinosis, pain may occur with active or passive dorsiflexion because the tendon is stretched. Pain may occur in active plantar flexion when there is adequate resistance to the motion, such as attempting to stand on tiptoes.

Pain is felt because the muscle contraction pulls on the damaged tendon. Pain is also common with resisted isometric contractions of plantar flexion for the same reason.

Pain may also appear near the insertion of the Achilles tendon in other conditions where repetitive overuse is the cause. For example, the retrocalcaneal bursa is located near the distal Achilles tendon. Repetitive compression of this bursa may produce pain very similar to that in Achilles tendinosis. Pressing on the distal Achilles tendon could cause pain with either Achilles tendinosis or retrocalcaneal bursitis. Palpation alone is not a good indicator to discriminate between these two conditions.

The Achilles tendon pinch-test is one way to distinguish bursitis from tendinosis (see the Figure to the Right). In this procedure, the practitioner pinches the Achilles tendon just proximal to the region where the retrocalcaneal bursa is located. If pressure reproduces pain, then retrocalcaneal bursitis is not likely to be the problem.

However, keep in mind that absence of pain during the pinch-test does not necessarily mean there is no Achilles tendinosis. Remember, collagen degeneration within the tendon can exist for some time before it produces pain. Your assessment should rely on many factors from the history and physical examination that help you identify the nature of the condition and the tissues involved.

References