To determine which factors are associated with ITBS across muscle function, gait, training, and psychosocial variables.
This case control study involved 45 participants (11 ITBS female, 14 control female, 10 ITBS male, 10 control male) exploring 42 independent variables. 8 gait biomechanical variables were measured via 16 infrared 3D optical motion analysis cameras (Oqus 300, Qualisys, Gothenburg, Sweden) and analysed via Qualisys Track Manager software (QTM 2022, Qualisys, Gothenburg, Sweden). A AMTI BMS600900 force plate (Advanced medical technology incorporated, MA, USA) was used for kinetics. 42 reflective markers were attached to the participants and 10 running trials in a 25-metre lab were taken of the entire gait cycle. 18 concentric and eccentric muscle force variables of the lower limbs were assessed via isokinetic dynamometer and 9 muscle function variables were assessed via standing heel raise to fatigue, single leg rise test and side lying hip abduction to fatigue testing. 4 Training variables were assessed via questionnaire. Motivation was assessed via BREQ-2, passion via Vallerand’s passion scale and sleep quality via PSQI. Statistical analysis (SPSS version 29) assessed normality and homogeneity of variation via Shapiro-Wilk and Leven’s test respectively, then one way ANOVA and Tukey HSD post hoc or Kruskal-Wallis with Dunn procedure with Bonferroni correction followed, depending on the normality testing outcome.
18 of the 42 variables showed significant differences between groups however 14 were sex differences. Comparing ITBS to controls in sex specific groups, males with ITBS had significantly weaker knee extensors; knee extensor concentric torque in the symptomatic leg vs control dominant leg (male control 189.71± 47.15 Nm vs ITBS male 135.38 ± 40.9Nm, p-value 0.012, 95% CI -99.24- -9.24) knee extensor concentric limb symmetry index (LSI) (Adjusted p-value 0.012), Knee extensor eccentric LSI (Adjusted p-value 0.022). Both ITBS males and females reported significantly greater changes in training, (ITBS males 51.3 ± 41.17% vs control males -8.45 ± 30.41%, adjusted p-value 0.018) (ITBS females 119.55 ± 129.74% vs control females 10.36 ± 20.61%, adjusted p-value 0.007). Both significantly increased their milage compared to controls.
Males with ITBS demonstrate reduced knee extensor torque in the symptomatic leg, alongside deficits in concentric and eccentric limb symmetry index (LSI). Additionally, both male and female ITBS participants significantly increased their training distances in the four weeks leading up to symptom onset compared to control runners.
Clinicians should prioritise assessing knee extensor strength in males and recent training load increases in all ITBS patients, as these were the primary differentiators between symptomatic and control groups. Conversely, gait analysis, muscle function assessments around the hip and knee flexors, and psychosocial variables showed minimal differences between groups, suggesting that these may be of lower priority at initial assessments.
Iliotibial band syndrome
