Table 1

Effects of interventions across primary outcomes by comparison, with Grading of Recommendations Assessment, Development and Evaluation strength of evidence and strength of recommendation ratings

ComparisonOutcomeTime pointParticipantsOverall effect estimate
MD (95% CI)		HeterogeneitySoESoRStudies
χ2 pI²
Comparison 1Eccentric exercise vs no exercise therapy, placebo therapy or advice to restVISA-A12 w2518.0 (14.86 to 21.14)+++−§↑? 31
4 m5020.6 (11.69 to 29.51)+++−§ 37
Pain VAS12 w20−33.0 (−44.96 to 21.04)+++−§ 42
12 w369.3 (−0.50 to 19.10)+++−§ 29
4 m50−23.0 (−34.45 to 11.55)+++−§ 37
Pain on tendon palpation VAS12 w32−22.5 (−43.37 to 1.63)+++−§ 32
SF-36 (Quality of Life)12 w360.5 (−12.23 to 11.23)+++−§NR 29
Comparison 2Eccentric exercise vs concentric exercisePain VAS8 w32−11.0 (−15.34 to 6.66)+++−§NR 45
Eccentric exercise vs heavy slow resistance exerciseVISA-A12 w47−4.80 (−13.93 to 4.33)+++−§ 34
52 w47−4.25 (−12.70 to 4.20)+++−§
Pain VAS12 w473.00 (−10.75 to 16.75)+++−§
52 w476.85 (−2.41 to 16.11)+++−§
Eccentric exercise vs stretching exercisePain (4-point Likert scale)12 w300.00 (−0.55 to 0.55)++−−*,§ 44
Quality of life (4-point Likert scale)12 w300.20 (−1.03 to 0.63)++−−*,§
High intensity vs lower intensity eccentric exerciseVISA-A12 w101−1.83 (−11.12 to 7.47)5.300.762%++−−†,§ 30 38 41
Pain VAS12 w606.30 (−4.45 to 17.04)0.370.250%+++−§ 38 41
Combined protocol (eccentric, concentric, power and stretching) vs lower dosage programmeFunctional performance (plantar flexion)12 w471.00 (−2.06 to 4.06)+++−§ 39
6 m521.00 (−2.37 to 4.37)+++−§
Functional performance (jump test)12 w53−2.00 (−5.18 to 1.18)+++−§
6 m300.00 (−5.32 to 5.32)+++−§
Functional performance (toe raise test)12 w55−4.00 (−10.95 to 2.95)+++−§
6 m50−3.00 (−10.19 to 4.19)+++−§
Eccentric exercise vs whole-body vibration trainingPain on tendon palpation VAS12 w42−12.80 (−30.92 to 5.32)+++−§ 32
Comparison 3Orthoses vs no orthoses or placebo therapyPDI4 w17−3.97 (−9.41 to 1.47)+++−§↓? 22
VISA-A3 m1402.90 (−3.12 to 8.92)++++ 28
12 m1400.3 (−5.35 to 5.95)++++
SF-36 (Physical Function)3 m140−0.1 (−5.04 to 4.84)++++
12 m1401.7 (−2.54 to 5.94)++++
Comparison 4Splinting and eccentric exercise vs eccentric exercise onlyVISA-A12 w1132.6 (−1.09 to 66.29)++−−*,§↓? 33
12 w63−1.8 (−15.18 to 11.58)++−−*,§ 27
12 m502.5 (−9.92 to 14.92)++−−*,§
5 y463.20 (−4.90 to 11.30)++−−*,§
Pain VAS12 w97−0.70 (−1.66 to 0.26)+++−§ 13
FAOS (symptoms)12 w120−1.63 (−8.47 to 5.21)0.850.640%+++−§ 13 14
12 m25−6.00 (−20.52 to 8.52)+++−§ 14
FAOS (pain)12 w120−3.50 (−10.49 to 3.48)0.530.330%+++−§ 13 14
12 m25−4.00 (−18.18 to 10.18)+++−§ 14
SF-36 (Physical Function)12 w651.60 (−6.11 to 9.61)++−−*,§ 36
Comparison 5Eccentric exercise vs splintingSF-36 (Physical Function)12 w63−0.30 (−6.53 to 5.93)++−−*,§↑? 36
FAOS (symptoms)12 w216.00 (−8.58 to 20.58)+++−§ 14
12 m234.00 (−11.14 to 19.14)+++−§
FAOS (pain)12 w2113.00 (−3.33 to 29.33)+++−§
12 m233.00 (−10.56 to 16.56)+++−§

  • *Moderate or high risk of bias.

  • †Inconsistency.

  • §Imprecision.

  • ++++ high level of evidence; +++− moderate level of evidence; ++−− low level of evidence; +−−− very low level of evidence; ↑↑ strong recommendation for intervention; ↑? conditional recommendation for intervention; ↓? conditional recommendation against intervention; ↓↓ strong recommendation against intervention.FAOS, Foot and Ankle Outcome Scale; m, month; MD, mean difference; NR, no recommendation for or against one intervention compared with the other; PDI, Pain Disability Index; SF-36, 36-Item Short Form Survey; SoE, strength of evidence; SoR, strength of recommendation; VAS, Visual Analogue Scale; VISA-A, Victoria Institute of Sport Assessment–Achilles; w, week; y, year.