Acute Achilles tendon rupture: The impact of physiological and psychological factors on function and return to activity

Abstract

Unfortunately, there is no guarantee of a full return to physical activity after an Achilles tendon rupture. About 20% of those who sustain the injury do not return to their previous level of physical activity. Although the reasons for this have been examined, no definitive conclusion has been reached. The main aim of this thesis was to gain knowledge of what can cause an incomplete recovery, which might negatively influence the return to physical activity. In this thesis, we try to identify interventions to eliminate the causes of incomplete recovery after an Achilles tendon rupture. In Study I foot structure was evaluated. We compared the uninjured and the injured sides 6 years after an Achilles tendon rupture. Two treatment groups (surgical and non-surgical) were also compared. Lower values for navicular drop and drift were found in the foot structure of the injured side in all participants, meaning that the translation of the navicular bone was less on the injured side compared with the uninjured side. The foot structure values (longitudinal arch angle and navicular drop and drift) were lower on the uninjured side in the surgically treated group compared with the non-surgical group, while there were no differences between the groups on the injured side. The effect of fatigue on the kinetics of the lower extremities was evaluated in Study II, two years after an Achilles tendon rupture. The peak power values of the ankle, knee and hip during landing and push-off for a drop countermovement jump were used for evaluation before and after a fatigue protocol. The results showed greater effect on the ankle joint after the fatigue protocol on the uninjured side compared with the injured side. However, there were no differences before and after the fatigue protocol in the knee and hip joints. In Study III, the impact of fear of reinjury on the kinetics in the lower extremities during a drop countermovement jump was evaluated 2 years after an Achilles tendon rupture. The participants were divided into two groups (Fear group and No-Fear group) depending on their answer to the question: “Do you ever refrain from any activity due to fear of reinjuring your Achilles tendon?”. The peak power values of the ankle, knee and hip joints during a drop countermovement jump were compared between the two groups. The results demonstrated increased asymmetry of the lower leg kinetics in the injured side in the Fear group, with less power in the ankle joint and increased compensatory power in the knee joint compared with the injured side in the No-Fear group. A qualitative content analysis was performed in Study IV, aimed at identifying factors that affect return to activity after an Achilles tendon rupture. Twenty participants were interviewed 4-6 years after an Achilles tendon rupture. The interviews were analysed and coded in order to categorize factors that collectively determine the thread/theme of the interviews. The overarching theme of the study was “Help me and then I can fix this”. This theme can be interpreted to the prerequisite that if the support one needs is in order, one can handle the next step. In summary, it is obvious that various physiological and psychological factors affect the return to activity. However, none of the factors examined in this thesis pointed the way towards a clear strategy. The effect of these factors appears to vary between individuals. It can thus be concluded that individualized treatment and rehabilitation are important, with frequent updates and evaluation of progress.