Patellar tendinopathy : on evaluation methods and rehabilitation techniques

Background: Patellar tendinopathy is an increasingly common overuse and degenerative injury for recreational and elite athletes. The management of this injury is often difficult and frustrating and the treatment may take a long time. There is therefore a need for efficient and well-evaluated treatment protocols based on evidence based rehabilitation training. The aim of this thesis was to evaluate and develop new training techniques and treatment protocols for active patients with patellar tendinopathy.

Material, Methods and Results: Outcome evaluation instrument such as the VISA-P score for patellar tendinopathy, which are easily administrated, clinically and scientifically standardized and allow systematical follow-up of chronic symptoms are important and useful. The VISA-P questionnaire has been translated and culturally adapted to be the sensitive for changes during treatment. The translated score showed good test-retest reliability when used to evaluate symptoms of patellar tendinopathy and for tests of physical activity.

A new eccentric overload device Bromsman in which controlled and safe training can be performed may play an important role for the development of new rehabilitation protocols. The device can handle different heavy loads on a barbell and showed a load- and resistance dependency and no significant difference between testretest. A direct feed-back system of force under each foot is a new feature and can make rehabilitation very specific when suffering from a unilateral injury.

The load on the patellar tendon during four different eccentric squat exercises was measured on the decline board and in Bromsman. Eccentric work, mean force and peak patellar force and angle at peak force were greater for squats on a 25 degree decline board compared to horizontal surface, but higher knee load forces for the same measurements were observed in Bromsman.

In a prospective randomized study two eccentric training methods; the eccentric overload device Bromsman and the 25 degree decline board; were compared. The clinical evaluation of both training techniques improved the VISA-P outcome score for patients with patellar tendinopathy problem. There was no difference between the groups. The number of patients in this study was limited.

Conclusions: The VISA-P questionnaire is useful for research and clinical evaluation of patients with patellar tendinopathy. The new eccentric overload device Bromsman is safe for high performance and rehabilitation training with eccentric overload for multi-joint movement. There are different biomechanical loading pattern on the knee during different squat exercises. It is therefore important to individualize and to be more precise when designing a rehabilitation program. After 12 weeks eccentric overload treatment in the new device or a decline board the majority of patellar tendinopathy patients could be regarded as more or less symptom free.

List of scientific papers

I. Frohm A, Saartok T, Edman G, Renstrom P (2004). Psychometric properties of a Swedish translation of the VISA-P outcome score for patellar tendinopathy. BMC Musculoskelet Disord. 5: 49.
https://doi.org/10.1186/1471-2474-5-49

II. Frohm A, Halvorsen K, Thorstensson A (2006). A new device for controlled eccentric overloading in training and rehabilitation. Eur J Appl Physiol. 94(1-2): 168-74.
https://doi.org/10.1007/s00421-004-1298-8

III. Frohm A, Halvorsen K, Thorstenson A (2006). Patellar load in different types of eccentric squats. [Submitted]

IV. Frohm A, Saartok T, Halvorsen K, Renstrom P (2006). Eccentric treatment for patellar tendinopathy - a prospective randomized study of two rehabilitation protocols. [Submitted]