Efficacy of different load intensity and time-under-tension calf loading protocols for Achilles tendinopathy (the LOADIT trial): protocol for a randomised pilot study

Abstract

Background: Modifying variables in exercise prescription can produce specific effects on Achilles tendinopathy outcomes. This study aims to determine the feasibility of conducting an adequately powered randomised trial in the future to assess the efficacy of different load intensity and time-under-tension exercise parameters for improving pain and function in individuals with persistent midportion Achilles tendinopathy. Methods: The trial is designed as prospective, four-armed feasibility and randomised pilot trial with 3 months follow-up. Interventions will be provided in a gym setting. The investigator, who will be blind to the allocation of participants, will conduct all pre-and post-intervention assessments. Forty-eight male participants with Achilles tendinopathy will be recruited from the community. We will use a 2 × 2 factorial design with factors of load intensity (six or eighteen repetitions maximum) and time-under-tension (two or six second repetitions). Participants will be randomised into one of the testing groups: six RM with two second repetitions, six RM with six second repetitions, eighteen RM with two second repetitions or eighteen RM with six second repetitions. Trial feasibility will be indicated by the rate of conversion, recruitment and retention, adherence to the interventions by participants, the utility of videoconferencing mode for weekly exercise supervision, incidence of adverse events, and feasibility of future economic evaluation. The secondary clinical outcomes will assess pain and disability, participant impression of change, satisfaction, health-related quality of life, physical activity, work absenteeism, psychological measures at baseline, 6 and 12 weeks, and plantarflexor contractile dysfunction (torque, rate of force development and muscle force steadiness) at baseline and 12 weeks. These clinical outcomes are primarily measured to provide information regarding potential treatment effects and trends.

Telehealth sounds a bit challenging, but it has potential: participant and physiotherapist experiences of gym-based exercise intervention for Achilles tendinopathy monitored via telehealth

“…In addition, only 58% of the trials measured adherence, and it was assessed via self-report which may be prone to recall bias if participants need to recall over longer periods [6]. In response, we undertook a feasibility trial to compare the efficacy of different loading parameters (load-intensity or time-undertension on clinical outcomes among individuals with Achilles tendinopathy [8]. The exercise intervention was monitored using videoconferencing and was undertaken by participants in their local gym environment.…”

“…Qualitative research enables participants to provide a detailed account of their experiences and present their own perspectives and interpretation of these experiences [14], which cannot always be captured using quantitative methods [15]. This qualitative study was nested within a pilot randomised trial [8] and aimed to explore the experience of participants and physiotherapists with gym-based exercise interventions for Achilles tendinopathy with weekly telehealth monitoring (via videoconference). Understanding stakeholder views may help to develop acceptable and effective telehealth interventions for Achilles tendinopathy.…”

Efficacy of Different LOAD-Intensity and Time-Under-Tension Exercise Interventions for Achilles Tendinopathy (The LOADIT Trial): A Randomised Pilot Trial

“…Participants were randomly allocated into one of four groups: 6 RM with two second repetitions; 6 RM with 6 second repetitions; 18 RM with two second repetitions; or 18 RM with 6 second repetitions group (Figure 1). The methods are described in the published protocol [17]. The study was reported in accordance with the CONSORT extension for randomised pilot and feasibility trials [18] and the TIDieR guide [19].…”

“…During this session, exercise adherence and delity (prior to providing feedback), adverse events, use of co-interventions, and productivity data were collected. Participants were taught calf raise exercise technique [17] using parameters speci c to their group allocation (Table 1) and the exercises were externally paced using a metronome (via smartphone application). Participants were instructed to exercise to volitional failure and how to progress and regress exercise based on di culty with the exercise and pain experienced.…”

“…After the baseline testing of the repetition maximum, exercise intensity was adjusted down by 10% in all groups to reduce the risk of muscle soreness related to commencement of unaccustomed exercise. Further exercise details are provided in additional le 1 and the protocol [17]. Table 1.…”