Table 2. Demographic and baseline characteristics of the study’s patients.
| Characteristic | Total sample (n = 60) | Experimental group (n=30) | Control group (n=30) |
| Age, y | 31.36±5.79 | 30.60±6.04 | 32.12±5.52 |
| Body mass, kg | 72.51±10.78 | 73.42±10.72 | 71.60±10.96 |
| Body height, cm | 171.30±8.53 | 170.23±7.84 | 172.37±9.17 |
| Body mass index, kg/m2 | 24.71±3.35 | 25.34±3.47 | 24.08±3.17 |
| Sex, n (%) | |||
| Female | 24 (40) | 13 (43.3) | 11 (36.7) |
| Male | 36 (60) | 17 (56.7) | 19 (63.3) |
| Symptoms, n (%) | |||
| Unilateral | 12 (20) | 7 (23.3) | 5 (16.7) |
| Bilateral | 48 (80) | 23 (76.7) | 25 (83.3) |
| Pain rating (0-10) | 5.90±1.43 | 6.10 ±1.52 | 5.70±1.34 |
| Pain duration, (months) | 58.75±29.68 | 60.27 ±30.66 | 57.23±29.10 |
| Smoking status, n (%) | |||
| Never smoked | 46 (76.7) | 21 (70) | 25 (83.3) |
| Current | 7 (11.7) | 5 (16.7) | 2 (6.7) |
| Past | 7 (11.7) | 4 (13.3) | 3 (10) |
| Education level, n (%) | |||
| High school or less | 21 (35) | 13 (43.3) | 8 (26.7) |
| Bachelor’s degree | 26 (43.3) | 11 (36.7) | 15 (50) |
| Master’s degree or higher | 13 (21.7) | 6 (20) | 7 (23.3) |
| Marital status, n (%) | |||
| Married/cohabitating | 38 (63.3) | 19 (63.3) | 19 (63.3) |
| Single | 12 (20) | 8 (26.7) | 4 (13.3) |
| Separated/divorced/widowed | 10 (16.7) | 3 (10) | 7 (23.3) |
Abbreviations: Continuous variables were expressed as mean ± standard deviation and categorical variables as number (n) and percentage (%). Experimental group, education followed by trunk and hip exercises; Control group, trunk and hip exercises.
https://doi.org/10.1016/j.apmr.2023.08.030
Table 3. Outcomes of linear mixed model for primary and secondary results of each group. Treatment effects measured at 8-weeks post-intervention and 3-months follow-up.
| Characteristic | Experimental group | Change relative to baseline (%) | Control group | Change relative to baseline (%) | Group Difference, Mean (95% CI) | Effect Size† | Main Effect of Time | Interaction Effect | Bonferroni post-hoc tests | |||
| Mean ± SDa | Mean ± SDa | F1,58 | P-value | F1,58 | P-value | Time | Group | |||||
| Primary Outcome Measure | ||||||||||||
| Pain (VAS) | ||||||||||||
| Baseline | 6.10±1.52 | NA | 5.70±1.34 | NA | 0.40 (-0.229 to 0.788) | NA | ||||||
| Post-intervention | 3.41±1.47 | 44.10 ↓ | 3.93±1.26 | 31.05 ↓ | -0.51 (-0.890 to 0.131) | 0.38 | 94.60 | <0.001 | 7.82 | 0.001 | Baseline > 8 wk, 3 mo (p<0.001b,c) | 3 mo(p=0.032) |
| Follow-up | 2.29±1.14 | 62.46 ↓ | 2.91±0.97 | 48.95 ↓ | -0.60 (-1.103 to -0.069) | 0.59 | ||||||
| Secondary Outcome Measures | ||||||||||||
| Function (KOS-ADL) | ||||||||||||
| Baseline | 64.90±8.918 | NA | 66.57±7.48 | NA | -1.75 (-0.710 to 0.304) | NA | ||||||
| Post-intervention | 76.35±6.56 | 17.64 ↑ | 74.49±6.03 | 11.90 ↑ | 1.85 (-0.214 to 0.804) | 0.30 | 72.99 | <0.001 | 7.65 | 0.005 | Baseline < 8 wk, 3 mo (p<0.001b,c) | 3 mo(p =0.036) |
| Follow-up | 0.55±5.66 | 24.11 ↑ | 77.41±5.76 | 16.28 ↑ | 3.20 (0.034 to 1.065) | 0.55 | ||||||
| Pain catastrophizing (PCS) | ||||||||||||
| Baseline | 20.10±4.77 | NA | 18.80±4.87 | NA | 1.32 (-0.239 to 0.778) | NA | ||||||
| Post-intervention | 12.96±4.04 | 35.52 ↓ | 15.29±4.52 | 18.67 ↓ | -2.32 (-1.059 to -0.028) | 0.54 | 281.68 | <0.001 | 47.34 | <0.001 | Baseline > 8 wk, 3 mo (p<0.001b,c) | 8 wk (p=0.007); 3 mo (p=0.043) |
| Follow-up | 9.21±3.69 | 54.18 ↓ | 12.04±4 | 35.96 ↓ | -2.82 (-1.258 to -0.213) | 0.74 | ||||||
| Kinesiophobia (TSK) | ||||||||||||
| Baseline | 42.47±7.20 | NA | 39.93±7.11 | NA | 2.71 (-0.155 to 0.865) | NA | ||||||
| Post-intervention | 32.07±7.05 | 24.49 ↓ | 35.79±6.44 | 10.37 ↓ | -3.56 (-1.067 to -0.035) | 0.55 | 157.42 | <0.001 | 52.61 | <0.001 | Baseline > 8 wk, 3 mo (p<0.001b,c) | 8 wk (p=0.045); 3 mo (p=0.002) |
| Follow-up | 27.89±4.99 | 34.33 ↓ | 32.56±5.90 | 18.46 ↓ | -4.54 (-1.383 to -0.326) | 0.85¥ | ||||||
| Muscles strength (BW) | ||||||||||||
| Hip abductors | ||||||||||||
| Baseline | 16.19±5.08 | NA | 17.24±4.30 | NA | -1.05 (-0.731 to 0.285) | NA | ||||||
| Post-intervention | 21.41±4.94 | 32.24 ↑ | 20.76±3.85 | 20.42 ↑ | 0.64 (-0.36 to 0.654) | 0.15 | 387.33 | <0.001 | 0.042 | 0.84 | Baseline < 8 wk, 3 mo (p<0.001b,c) | N.S |
| Follow-up | 23.73±4.71 | 46.57 ↑ | 22.65±3.64 | 31.38 ↑ | 1.07 (-0.252 to 0.765) | 0.26 | ||||||
| Hip external rotators | ||||||||||||
| Baseline | 12.07±3.62 | NA | 13.54±3.78 | NA | -1.41 (-0.908 to 0.114) | NA | ||||||
| Post-intervention | 18.04±4.02 | 49.46 ↑ | 17.54±3.77 | 29.54 ↑ | 0.51 (-0.378 to 0.635) | 0.13 | 196.15 | <0.001 | 0.001 | 0.97 | Baseline < 8 wk, 3 mo (p<0.001b, c) | N.S |
| Follow-up | 21.12±4.08 | 74.98 ↑ | 20.25±3.96 | 49.56 ↑ | 0.90 (-0.291 to 0.724) | 0.22 | ||||||
| Hip extensors | ||||||||||||
| Baseline | 18.64±4.27 | NA | 19.46±3.93 | NA | -0.77 (-0.707 to 0.308) | NA | ||||||
| Post-intervention | 23.38±4.27 | 25.43 ↑ | 22.84±3.87 | 17.37 ↑ | 0.57 (-0.374 to 0.639) | 0.13 | 359.82 | <0.001 | 0.039 | 0.84 | Baseline < 8 wk, 3 mo (p<0.001b, c) | N.S |
| Follow-up | 25.56±4.08 | 37.12 ↑ | 24.68±3.68 | 26.82 ↑ | 0.89 (-0.281 to 0.742) | 0.23 | ||||||
| Knee extensors | ||||||||||||
| Baseline | 25.18±4.78 | NA | 26.51±4.63 | NA | -1.3 (-0.791 to 0.226) | NA | ||||||
| Post-intervention | 32.03±4.51 | 27.20 ↑ | 31.05±4.32 | 17.13 ↑ | 0.95 (-0.286 to 0.730) | 0.22 | 435.27 | <0.001 | 0.024 | 0.88 | Baseline < 8 wk, 3 mo (p<0.001b, c) | N.S |
| Follow-up | 34.17±4.70 | 35.70 ↑ | 33.29±4.24 | 25.58 ↑ | 0.87 (-0.311 to 0.704) | 0.20 |
Abbreviations: †, Effect size (Cohen’s d); ¥, Large effect size (d >0.80) based on the study of Cohen (1988); ↓, Decrease; ↑, Increase; a, Values are expressed as means ± standard deviations; b, Results of Bonferroni Post Hoc tests in the experimental group; c, Results of Bonferroni Post Hoc tests in the control group; ADL, Knee outcome survey activities for daily living; BW, Body weight; CI, Confidence Interval; Control group, trunk and hip exercises; Experimental group, education followed by trunk and hip exercises; KOS- PCS, Pain Catastrophizing Scale; NA, Not applicable; N.S, Not significant; TSK, Tampa Scale for Kinesiophobia; VAS, Visual Analogue Scale.