OBJECTIVE: To compare the effectiveness of intermittent blood flow restriction (iBFR) training with that of high-load resistance training in improving patellofemoral pain (PFP).
DESIGN: Double-blind randomized trial.
SETTING: A college rehabilitation center.
PARTICIPANTS: Individuals with PFP (N=42).
INTERVENTIONS: Participants were randomly assigned to 2 groups: iBFR group and control group. iBFR group performed low-load resistance training at 30% of 1 RM under individualized limb occlusion pressure (LOP) at 80% of their individualized LOP. Control group engaged in high-load resistance training with a sham BFR at 70% of 1 RM, using a BFR cuff inflated to 20 mm Hg. Training sessions were conducted 3 times per week for 8 weeks, with follow-up assessments at 8 and 24 weeks.
MAIN OUTCOME MEASURES: Pain and self-report function assessed at baseline, postintervention, and 24-week follow-up. Quadriceps muscle strength and thickness assessed at baseline and postintervention. All adverse events were recorded during the trial.
RESULTS: Both iBFR and standard exercise resulted in significant improvements, but between-group comparisons indicated no conclusive difference in the primary outcomes [P=.163; mean difference, -8.75 (95% confidence interval, -21.18 to 3.69)]. Muscle strength and thickness increased similarly in both groups, with no significant differences observed. However, patients from the iBFR group had higher adherence and fewer adverse events, highlighting its safety and tolerability.
CONCLUSIONS: iBFR combined with low-load resistance training was found to be not statistically significant different from high-load resistance training in terms of pain relief and function improvement in PFP patients, with fewer adverse events, indicating that it may be a safer and more patient-friendly rehabilitation option that is sutiable for tailored treatment based on individual preferences and tolerance levels.
| Discipline Area | Score |
|---|---|
| Rehab Clinician (OT/PT) |  |
| Physician |  |
Physician rater
Both low-load iBFR (30% 1RM) and high-load resistance training (70% 1RM) significantly reduced pain and improved function over 8 weeks, with no significant between-group differences in quadriceps strength. iBFR recorded zero adverse events, whereas 19% of the high-load group experienced pain exacerbations during load adjustments. However, the small, active cohort (n=42) limits generalizability and statistical power to detect smaller, clinically meaningful differences. Therapist blinding was also unfeasible.
Physician rater
This study compared the effectiveness of intermittent blood flow restriction (iBFR) training with that of high-load resistance training for improving patellofemoral pain (PFP). The authors concluded that the experimental group was not better than the control group. This trial seems to be at low risk of bias, however the small sample size increases the risk of type II error (false negative). The confidence interval asymmetry in favor of the experimental group raises the hypothesis that there may be an effect in favor to iBFR. Trial with larger sample sizes are necessary.
, McMaster University