The role of infrared thermal imaging in the assessment of chronic midportion Achilles tendinopathy

Infrared thermal imaging cameras (IRC) are non-contact devices that allow the capture of radiation presented in the form of colour-coded images, therefore they may provide an effective method of assessment for chronic midportion Achilles tendinopathy. Some of the features of the condition point towards regional heat change and could be reflected through surface skin temperature (TSK) change.This thesis firstly investigated the methodological aspects of IRC’s and created a robust method of Achilles tendon (AT) assessment (chapter 3). The first experimental study (chapter 4) assessed the baseline differences in TSK of the AT midportion in symptomatic (SX) and asymptomatic (ASX) individuals. It was found that no differences existed between the two. There were no differences between the symptomatic AT’s (SX_AT) or ASX AT’s (ASX_AT) or between the left and right limbs of control participants. Chapter 5 assessed the TSK responses of SX and ASX individuals in response to a 15-minute treadmill running task. Significant TSK elevations were found in all groups following the task, with the control group presenting with statistically significantly hotter absolute TSK values compared to the SX_AT and the ASX_AT groups. The SX participants then completed a 12-week heavy slow resistance (HSR) rehabilitation programme before conducting a repeat of the running task. No significant differences were found between the SX_AT and the control AT’s which appeared to show a normalisation of TSK response. Significant differences still existed between the ASX_AT’s and the control group. The 12-week HSR programme resulted in significant improvement in symptom scores in SX individuals. Chapter 6 assessed the TSK responses of SX and ASX individuals to a single leg hopping (SLH) task. Statistically insignificant TSK decreases were seen post-SLH task and there were no significant differences between groups. There were statistically significant between-group differences in some kinematic and kinetic variables associated with SLH. The SX participants then underwent a 12-week HSR rehabilitation programme before conducting a repeat of the SLH task. There were no between-group differences in TSK or kinematic or kinetic variables. There were statistically significant improvements in symptom, effort and pain scores following the 12-week HSR programme. Overall, this thesis demonstrated that the FLIR ONE is an acceptable objective measurement tool for the assessment of TSK. Some thermal responses to loading tasks were noted in the midportion of the AT in those suffering from chronic midportion Achilles tendinopathy, however the lack of differences between SX and ASX ATs meant that it would be difficult to objectively measure the progress of pathology based on TSK. Due to the success in detecting some thermal responses from the chronic AT, the tool may be used at other joints for the assessment of more reactive or acute pathologies that may display greater regional heat change, however, this warrants further investigation. HSR rehabilitation has proved successful for the management of chronic midportion Achilles tendinopathy alongside normal recreational running training regimes. Key words: Achilles Tendon; Achilles tendinopathy; Infrared thermal imaging; Heavy slow resistanc