Comparative Effects of Pelvic PNF and HVLA Thrust in Sacroiliac Joint Dysfunction

This study, titled "Comparative Effects of Pelvic PNF and HVLA Thrust on Pain, Mobility, and Flexibility in Sacroiliac Joint Dysfunction," is a single-blinded randomized clinical trial (RCT) designed to evaluate and compare the therapeutic efficacy of two widely used but never directly compared manual therapy interventions Pelvic Proprioceptive Neuromuscular Facilitation (PNF) and High-Velocity Low-Amplitude (HVLA) thrust manipulation in individuals diagnosed with sacroiliac joint dysfunction (SIJD), a musculoskeletal condition responsible for a substantial proportion of low back pain cases worldwide yet frequently under-recognized and inconsistently managed in clinical practice.

The trial will enroll a total of 62 participants, aged between 18 and 40 years, recruited from the rehabilitation departments of two collaborating institutions in Karachi, Pakistan Creek General Hospital and Dr. Ziauddin Hospital with the sample size derived through G\*Power software at a 95% confidence interval and 80% statistical power, based on a reference study, and inflated by 20% to account for anticipated attrition.

Eligible participants will be clinically diagnosed with SIJD by an orthopedic surgeon using a cluster of provocation and motion palpation tests, and must present with a baseline pain intensity greater than 4/10 cm on the Visual Analog Scale (VAS) persisting for more than four weeks, while individuals who are pregnant or postpartum, report pain exceeding 8/10 cm on VAS, have diagnosed disc herniation, spinal stenosis, piriformis syndrome, true leg length discrepancy, recent spinal or lower-limb surgery, recent spinal injections or SIJ manual therapy, or active infection, malignancy, or uncontrolled hypertension will be excluded. Following informed written consent, participants will be randomly allocated through a sealed-envelope simple randomization technique into two equal groups of 31: Group A receiving Pelvic PNF, involving diagonal pelvic patterns such as anterior depression and posterior elevation combined with Rhythmic Stabilization and Contract-Relax Stretch techniques, and Group B receiving HVLA thrust manipulation, a controlled high-velocity, low-amplitude manual force applied directly to the sacroiliac joint. Baseline assessments, including demographic data (age, gender, height, weight, BMI, dominant and affected side) and outcome measures, will be conducted by a blinded, trained physiotherapist-assessor to minimize observer bias, with the three primary outcomespain intensity (via VAS), lumbo-pelvic mobility (via the Modified-Modified Schober Test), and posterior-chain flexibility (via the Sit and Reach Test) evaluated at three time points: baseline, six weeks post-intervention, and a twelve-week follow-up to determine the sustainability of treatment effects.

The overall trial duration is set at six months following synopsis approval, and data will be analyzed statistically to test the null hypothesis (that HVLA is superior to Pelvic PNF) against the alternative hypothesis (that Pelvic PNF is superior to HVLA). Ethically, the study will proceed only after formal institutional approval, with all participants providing voluntary informed consent after receiving a Patient Information Sheet and adequate time for consideration, ensuring compliance with standard human-subject research protections.

By generating the first direct, objectively measured comparison between these two conservative, non-pharmacological interventions, this trial aims to fill a clearly identified gap in the physiotherapy literature and provide clinicians with evidence-based guidance for selecting the more effective treatment approach in managing sacroiliac joint dysfunction, thereby improving conservative care pathways and clinical decision-making in orthopedic and physiotherapy practice.