Comparison Between Moderate Load Exercises and High Load Exercises in the Rehabilitation of Runners with Achilles Tendinopathy: Blind Randomized Controlled Trial
Achilles tendon / Tendinitis / Physical Therapy
Objective: The primary objective of the study will be to investigate the short-term (6
and 12 weeks) and long-term (6 months) effects of a moderate load resistance
exercise intervention [55% of 1 Repetition Maximum (55%1RM)] in comparison to
high-load resistance exercise (90% of 1RM) in runners with Achilles tendinopathy in
terms of pain and symptom severity. Methods: Sixty amateur runners will be randomly
allocated into two groups: Group of high intensity exercises (GHI) and group of
moderate intensity exercises (GMI). The GHI will start the treatment with triceps surae
exercises with 55%1RM in the first week, 75%1RM in the second week and, from the
third week until the end of the 12 weeks of treatment, will perform the exercises with
90%1RM. The GMI will perform exercises with 55%1RM during the 12 weeks of
intervention. The RM load will be reassessed every 2 weeks and the total training
volume will be identical in both groups. Both groups will do strengthening exercises for
quadriceps and gluteal muscles and will continue to perform physical/sports activities
using the pain monitoring model strategy. Pain (VAS) and symptom severity (VISA-A),
maximum isometric strength of ankle, knee and hip muscles (handheld dynamometer),
function of plantar flexors (functional tests), kinesiophobia (TSK), physical activity level
(IPAQ-SF), quality of life (SF-12) and perception of improvement (GROC). Primary
outcomes (pain and symptom severity) will be evaluated before the intervention
(baseline), at week 6, at week 12 (end of intervention) and 6 months after the
intervention. The other outcomes will be evaluated at baseline and at the end of the
intervention. Results will be analyzed using the intention-to-treat principle and will be
compared by mixed-model analysis of variance (2-way ANOVA) with repeated
measures (group x time) and Bonferroni post hoc.