Feasibility of an Early Progressive Strength Exercise Programme for Acute Achilles Tendon Rupture

The aim of this study is to investigate the feasibility of an early progressive exercise program for patients with Achilles tendon rupture treated non-surgically. The outcomes will concern the patient's acceptability of the intervention, adherence to the intervention and safety of the healing tendon.

Regardless of choice of either surgical or non-surgical treatment, long-term muscular deficits and a decreased function after Achilles tendon rupture is found up to 10 years later. The majority of the patients are of working age and a deficit in physical performance will have impact on returning to work and sports. There has been promising results in treatments using early functional rehabilitation during the first eight weeks of treatment after both surgical and non-surgical treatment, but few studies has examined the effect of the exercises on its own. In general, descriptions of the exercise programs are lacking important information such as type, time of application, frequency, intensity and progression of the exercises. The primary aim is to test the feasibility of an early progressive exercise program for patients with Achilles tendon rupture treated non-surgically. Feasibility in this study will be defined as successful patient acceptability and compliance of the exercise intervention.

Weekly sessions introducing resistance exercises and monitoring the patients acceptability. The exercises are isometric contractions, seated heel-rise and elastic band. The patient register the amount of exercise in a home exercise journal. To protect the tendon while doing range of motion of the foot, dorsiflexion is restricted beyond neutral (0 degrees of dorsiflexion). The load on the strength exercises will progress from isometric contraction without external load to strengthening exercises with 10-20 RM (RM: Repetition Maximum). Each strength exercise can progress with added weight or stronger elastic band. The Borg scale is used to guide the patient to progress or regress the load in each exercise. The recommended level being "easy" to "hard" (2-5/10). It is emphasised that the exercises must not cause sudden or severe pain in the tendon, but muscle soreness is to be expected.

The participants will rate their acceptability (willingness) to perform the exercises on a 7-point Likert scale ranging from "very unacceptable" to "very acceptable". This is not a measure of whether the patient's symptoms have improved to normal physical function or any other satisfactory level at the specific time, but if it matches, their expectations of the content of an exercise program in this early phase and how they tolerate performing the exercises. The intervention program is categorised as "Unacceptable" if rated as the three lower scores ("very unacceptable" to "slightly unacceptable") and categorised as "Acceptable" if rated as the four higher scores ("neither acceptable or unacceptable" to "very acceptable"). The exercise program is considered feasible if acceptability of the exercise program is 80%. Defined as: ≥13/16 patients will rate the acceptability of the intervention as "acceptable".

The participants will register the number of training sessions and exercises they perform each day in a training journal. The compliance is measured as the mean number of exercise sessions they perform. The timeframe will be from the day they start the exercises to the end of week 9. The exercise program is considered feasible if the adherence to the exercise program is 50%. Defined as: ≥13/16 patients will perform ≥ 50% of the exercise sessions possible from start to end of week 9.

The Tampa scale of Kinesiophobia (TSK) is a questionaire consisting of 17 items concerning pain and kinesiophobia and has 4 answers from "Strongly disagree" to "Strongly agree". During the exercise intervention period and at 3 months follow,up the patients will fill out the score and subsequently they are asked to rate the appropriateness of the score on a 7 point Likert scale ranging from "strongly disagree" to "strongly agree".

Validated patient reported outcome measure. It contains 10 questions about physical performance in an 11-point Likert scale from zero to ten.

International Physical Activity Questionnaire (IPAQ) short form Danish version. It consists of 7 items concerning physical activity as time spent performing vigorous and moderate activities, the time spent walking and sitting during the past week. The IPAQ gives an estimate of the total weekly physical activity measured in MET-minutes per week and total minutes spent sitting.(MET: The Metabolic Equivalent of Task)

Indirect measure of the Achilles tendon length. It is measured in degrees between the axis of the fibula (from malleol to proximal head) and the line from the tip of the fibula to the head of the Fifth metatarsal bone.

The number of serious and minor adverse events is registered using open questions and a pre-defined list.

Muscle endurance is measured in seated heel-rise with MuscleLab Measurement system (Ergotest Technology, Oslo, Norway)

Inclusion Criteria: Acute Achilles tendon rupture treated non-surgically Diagnosed and treatment initiated within 3 days of injury Age 18-65, able and willing to participate in the intervention Able to speak and understand Danish Exclusion Criteria: Insertional Achilles tendon rupture on calcaneus or rupture in the musculo-tendinous junction of the triceps surae Previous Achilles tendon rupture or other conditions in either leg causing lower leg disability (pain, deficits in strength or range of movement) Treated with Fluoroquinolones or Corticosteroids within the last 6 months Diabetes Severe medical illness: ASA score higher than or equal to 3. (ASA: American Society of Anesthesiologists physical status classification system)