Psychological factors not strength deficits are associated with severity of gluteal tendinopathy: a cross-sectional study

Key points

1. 01Severe cases had significantly higher pain catastrophizing scores (mean 18.8) compared to moderate (13.6) and mild (8.6) groups (p<0.001).
2. 02Pain self-efficacy was lowest in the severe group (mean 40.8/60) vs moderate (47.8) and mild (53.9) (p<0.001).
3. 03Depression scores were incrementally higher across subgroups: mild 2.5, moderate 4.5, severe 7.4 out of 27 (p<0.001).
4. 04Hip abductor muscle torque did not differ across severity subgroups (p=0.52), ranging from 0.77 to 0.88 Nm/kg.
5. 05Severe cases had significantly lower total physical activity (349.5 vs 619.9 min/week in mild group; p=0.01) and greater waist girth (92.5 vs 86.5 cm; p=0.01).

How it was conducted

Design

Multi-centre cross-sectional cohort study using baseline data from a randomised clinical trial

Participants

203 adults (mean age 55 years, 82% female) with clinically and MRI-confirmed gluteal tendinopathy recruited from Brisbane and Melbourne, Australia

Severity subgroups

K-means cluster analysis of VISA-G scores identified mild (n=51, mean 76.5), moderate (n=103, mean 59.0), and severe (n=49, mean 42.7) subgroups

Measures

VISA-G (pain/disability), Pain Catastrophizing Scale, Pain Self-Efficacy Questionnaire, PHQ-9 depression, EQ-5D quality of life, hip abductor torque (handheld dynamometer), anthropometrics, Active Australia Survey

Analysis

MANCOVA with sex and site as covariates, Bonferroni post-hoc tests; Chi-square for categorical data; standardised mean differences calculated

What they found

• Severe vs mild: pain catastrophizing MD 10.22 (95%CI 6.16, 14.27; p<0.001).
• Severe vs moderate: pain catastrophizing MD 5.31 (95%CI 1.82, 8.80; p=0.001).
• Severe vs mild: pain self-efficacy MD -13.20 (95%CI -17.16, -9.24; p<0.001).
• Severe vs mild: depression (PHQ-9) MD 4.85 (95%CI 2.84, 6.86; p<0.001).
• Severe vs mild: quality of life (EQ-5D) MD -0.13 (95%CI -0.19, -0.07; p<0.001).
• Severe vs mild: total physical activity MD -258.23 minutes/week (95%CI -462.84, -53.63; p=0.01).
• Severe vs mild: waist girth MD 7.39 cm (95%CI 1.27, 13.51; p=0.01).
• Severe vs moderate: BMI MD 2.30 kg/m2 (95%CI 0.19, 4.41; p=0.03).
• Hip abductor torque: no significant subgroup difference (p=0.52); values ranged from 0.77 to 0.88 Nm/kg across subgroups.
• 37% of the severe group had some or extreme anxiety/depression on EQ-5D vs 18% (moderate) and 14% (mild).

Limitations

• Cross-sectional design prevents causal inference; it is unknown whether psychological distress precedes or follows greater severity.
• No healthy control group was included, limiting comparison to normative reference data for most measures.
• Physical activity was self-reported via questionnaire rather than measured with accelerometers, introducing recall bias.
• The small number of males (n=36, 18%) limits the generalisability of sex-stratified findings and reduced statistical power for male subgroup analyses.

Why it matters

For patients

Patients with more severe gluteal tendinopathy are likely experiencing psychological distress such as depression and catastrophising, which may be important to address alongside physical treatment.

For clinicians

Clinicians managing severe gluteal tendinopathy should screen for pain catastrophizing, low pain self-efficacy, and depression, as these factors, not hip strength, distinguish more severe cases and may guide stratified or psychologically-informed care.

For readers

This is the first study to characterise psychological profiles across severity levels of gluteal tendinopathy, supporting a biopsychosocial approach to assessment and treatment planning.