Understanding the effects of therapeutic tape in individuals with lateral elbow tendinopathy

Lateral elbow tendinopathy (LET) is a common musculoskeletal condition associated with elbow pain during gripping. The pathophysiology of LET involves degenerative changes of the extensor carpi radialis brevis tendon, pain system changes within the peripheral and the central nervous system, and motor impairments, such as altered muscle activity and wrist angle during gripping. One treatment option for LET is therapeutic tape, which has the potential to deload underlying musculotendinous tissue, or alter pain via tactile stimulation of the skin. However, the evidence for tape as a treatment for LET is yet to be synthesised. Additionally, the ways in which healthcare practitioners seek information about, and apply tape for LET, is unclear; highlighting a gap in the translation between research and clinical practice. A new type of tape, called biomechanical tape, is thought to deload underlying musculotendinous tissue. However, no studies have investigated the effectiveness of biomechanical tape on pain and function in individuals with LET. Therefore, this thesis aims to comprehensively review the current literature for the use of tape in LET, explore how and why practitioners are using therapeutic tape to treat LET, and examine whether biomechanical tape can be used to immediately improve pain and function for individuals with LET. Study 1 is a systematic review of the effects of therapeutic tape, as a standalone intervention, for LET. This review identified only eight studies, most at a high risk of bias, that investigated the effects of tape compared to a control or baseline condition. This review supports the use of diamond deloading rigid tape to immediately improve pain and grip strength in individuals with LET, while evidence for the effects of kinesiotape is conflicting. This study also confirms a lack of research examining the effects of biomechanical tape for LET. Study 2 reports the results of an anonymous survey of Australian healthcare practitioners regarding their use of tape for LET. The majority of respondents were physiotherapists, with most working in private practice. The survey found that approximately half of the respondents use a wide range of tape techniques to treat LET. Most respondents apply tape to reduce pain during occupational tasks, sport, or hobbies. Justification for tape use is largely based on experience and patient preference, with information regarding tape mostly gained from professional development courses. Together, Studies 1 and 2 demonstrate that while there is a paucity of high-quality literature regarding the use of tape for LET, it is a popular treatment option. Study 3 examined the between- and within-session reliability of measures commonly used in LET research, pain-free grip strength and pressure pain threshold. This study shows that while using a single trial and the mean of three trials of both outcomes demonstrates good to excellent reliability, the mean of three trials is recommended due to lower measurement error. This study also provides minimum detectable change scores for both between- and within-session study designs. Study 4 reports the clinical outcome measures of pain-free grip strength and pressure pain threshold from a single-blind, randomised crossover trial comparing the effects of biomechanical tape to a control tape and no tape condition. The study was designed to test the immediate effects, and the effects following a short exercise circuit that loaded the wrist extensors. There were no significant differences in pain-free grip strength or pressure pain threshold either immediately or following the exercise circuit. There was variability in the direction and magnitude of individual responses, which suggests that subgroup analysis within future treatment studies is warranted. Study 5 reports on muscle activity and wrist extension angle, measured during a submaximal gripping task in the randomised crossover trial, to explore potential mechanistic effects of biomechanical tape. This study observed several small, significant reductions in the percentage of maximal voluntary contraction for extensor digitorum communis and extensor carpi ulnaris, no significant changes for extensor carpi radialis brevis or longus, and no significant changes in wrist extension angle. While the observed decreases in muscle activity may not be large or consistent enough to be clinically significant on their own, these findings imply that there is a potential deloading effect of biomechanical tape. Overall, this thesis has found that while high-quality research investigating the effects of therapeutic tape in LET is lacking, use of tape is common, and practitioners rely on their own experience and patient preference to decide whether to use tape to treat LET. While biomechanical tape did not have a consistent, immediate effect on pain and function in a group of individuals with LET, there may be a small deloading effect, indicated by a reduction in muscle activity of some of the wrist extensors, that could benefit a subgroup of individuals. Based on these findings, future research exploring the characteristics of responders and non-responders is required to determine whether there is a role for biomechanical tape for individuals with LET.