Unsupervised daily home eccentric calf exercise did not differ significantly from a sham programme of upper-limb strength exercise for chronic midportion Achilles tendinopathy: in a randomised trial of 68 patients (34 per arm, mean age 52), VISA-A rose 10 points with calf exercise and 6 with the sham over 12 weeks, an adjusted difference of 4 points (95% CI −7 to 15), not significant
Main caveat: One trial of 68 patients; the 95% interval for the difference (−7 to 15 VISA-A points) is wide, so a clinically meaningful benefit of eccentric exercise is…
Janssen and colleagues asked how much of the short-term improvement seen with eccentric calf exercise in chronic midportion Achilles tendinopathy is due to the exercise itself. Adults with a clinical diagnosis were randomised to daily eccentric calf exercises or to a sham programme of daily upper-limb strength exercises, both done at home without supervision for 12 weeks.
VISA-A, a 0-100 questionnaire of Achilles symptoms and function, improved by a mean of 10 points (95% CI 2-22) with calf exercise and by 6 points (95% CI 2-15) with the sham.
The adjusted difference between the groups was 4 points in favour of calf exercise, with a 95% confidence interval from 7 points in favour of the sham to 15 points in favour of calf exercise, and was not statistically significant. Ten of the 68 participants (15%) were lost to follow-up.
The authors conclude that eccentric exercise done as an unsupervised home programme showed limited short-term effectiveness.
Participants
n = 68 adults with clinically diagnosed chronic midportion Achilles tendinopathy, 34 per arm.
Mean age 52 ± 10 years; 40% female.
Symptom duration, baseline VISA-A, activity level, sport and how "chronic" was defined: not in the abstract.
Protocol
Eccentric arm (EET): daily eccentric calf muscle exercises at home, unsupervised, for 12 weeks.
Sham arm (UET): daily upper-extremity strength training at home, unsupervised, for 12 weeks, used as a sham exercise therapy.
Primary outcome: change in VISA-A (0-100) over 12 weeks.
Analysis: linear mixed models, intention to treat; the between-group difference is adjusted (the covariates are not in the abstract).
Not in the abstract: the exercise dose (sets, repetitions, load and its progression), whether participants could run or play sport during the trial, what advice or education either group received, adherence, blinding of participants or assessors, registration, the sample-size target and the smallest difference the trial was powered to detect, secondary outcomes and adverse events.
Key Results
| Outcome at 12 weeks | Eccentric calf exercise (n = 34) | Sham upper-limb exercise (n = 34) | Between groups |
|---|---|---|---|
| VISA-A change (0-100) | +10 (95% CI 2-22) | +6 (95% CI 2-15) | adjusted difference 4 points (95% CI −7 to 15), not significant |
Lost to follow-up: 10 of 68 (15%); split by arm not in the abstract.
Both groups improved on average; the trial was not designed to say why the sham group improved (time, natural course, or the attention of taking part are all possible; not tested).
Practical Application
A home eccentric calf programme on its own, without supervision, was not shown to beat a sham of upper-limb exercise; this does not show that calf loading fails. In 68 patients (mean age 52) with chronic midportion Achilles tendinopathy, 12 weeks of daily unsupervised eccentric calf exercise improved VISA-A by 4 points more than a sham of upper-limb exercise, with a 95% interval from 7 points worse to 15 points better, so neither no benefit nor a benefit of up to 15 points is ruled out.
This is not treatment advice; a physiotherapist or physician diagnoses the tendon problem and sets the loading programme.
How it bears on [SYNTH-73] and [SYNTH-94]: the guides send load-related Achilles pain to a swap of the provoking load, a gradual return under a pain scale, and progressive calf loading for at least 12 weeks set by a clinician (REF-1380).This trial tested one narrower thing — eccentric calf exercise alone, done unsupervised at home — against a sham, and found no significant difference at 12 weeks.It did not test clinician-led or progressed loading, heavy slow resistance, education, load swapping or the pain-monitoring rule, so the guides' default is left standing; what it contests is the assumption that the eccentric exercise itself, done alone at home, carries a clear short-term effect.
Inference, not tested here: the base's comparison of heavy slow resistance with eccentric training (REF-626) found no difference between them and had no sham arm; with an unsupervised home eccentric programme not significantly better than a sham at 12 weeks here, "did not differ from eccentric training" is on its own a weak endorsement for the short term.
Not settled by this design: whether supervision, heavier or progressed loading, or a longer programme would separate from the sham; outcomes beyond 12 weeks; results in younger or athletic patients.
Limitations
One trial of 68 patients; the 95% interval for the difference (−7 to 15 VISA-A points) is wide, so a clinically meaningful benefit of eccentric exercise is neither shown nor excluded.
Short term only: 12 weeks.
15% lost to follow-up.
Unsupervised home programmes: adherence is not reported in the abstract, so low adherence may explain part of the null result.
An upper-limb exercise sham controls for taking part and doing exercise, not for the attention of supervised care; whether participants could tell which programme was the real one is not in the abstract.
Older patients (mean age 52); not shown to be athletes.
Written from the abstract only: the exercise dose, co-interventions, registration, blinding, sample-size calculation, secondary outcomes, adverse events and funding are unknown.
How this entry was checked and changed
Why this level
a randomised trial with 34 per arm (the rubric's A- band for 20 or more per arm when read in full), capped at B+ because only the abstract was read: risk of bias not read (abstract only)