New lower-limb gait biomechanical characteristics in individuals with Achilles tendinopathy: A systematic review update.

BACKGROUND: Variations in lower-limb biomechanics have recurrently been associated as aetiological factors for Achilles tendinopathy.

OBJECTIVE: To update a previous systematic review examining lower-limb gait biomechanics in Achilles tendinopathy.

DESIGN: Systematic Review.

DATA SOURCES: MEDLINE, EMBASE, CINAHL PLUS, SPORTDiscus and PUBMED databases searched from inception to May 2016.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies investigating adults with Achilles tendinopathy and lower-limb gait biomechanics including kinematics, kinetics, dynamic plantar-pressures, temporospatial parameters and muscle activity.

RESULTS: Fourteen studies were identified, involving 836 participants. Three were prospective studies and 11 were case-control designs. Selection and performance bias were high for all studies except the prospective studies, reporting bias was unclear for all studies. Significant effect size reductions in gait speed (d = -0.80), stride length (d = -0.84) and step length (d = -0.80) were calculated in runners with Achilles tendinopathy. Increased effect sizes for ankle eversion (d = 1.08), time to maximum pronation (d = -1.72), calcaneal inversion (d = -1.82) and ankle and hip joint moments were also established. Significant differences in plantar pressures and timing of ground reaction forces were calculated. Individuals with Achilles tendinopathy demonstrated differences in amplitude and timing of several lower-limb muscles, notably reductions in the onset of activity (d = 2.02) and duration of activation (d = 2.11) in the Gluteus Medius of subjects with Achilles tendinopathy.

CONCLUSION: Eighteen new biomechanical characteristics in individuals with Achilles tendinopathy have been established. This review highlights a topic rich in quantity, but generally weak in quality, consequently results should be interpreted cautiously. High powered prospective studies are required to determine causality.