The Science Behind HipTrac & Why it Works

The HipTrac is the first medical device which provides independent long axis hip traction for patients at home and in the clinic. HipTrac’s pneumatic cylinder delivers the exact traction force specified, from 0N to more than 1000N, and can maintain consistent force for as long as needed for a particular protocol. The video below is from an ultrasound of a hip, taken during a HipTrac traction session showing the movement of the hip joint with traction force of 400N.

HipTrac is relatively new, cleared for sale by the FDA in 2012.  The first case series has recently been published and other specific studies are underway. In the case series, two patients were treated with manual therapy, therapeutic exercise, and HipTrac. Two years after treatment, both patients described clinically meaningful improvements in self-reported function and pain were described.

Read the complete case series published in the January 2017 APTA Orthopaedic Physical Therapy Practice


Although HipTrac is a recent advancement, hip traction itself is a tested and proven therapy to help relieve the signs and symptoms associated with hip osteoarthritis, femoral-acetabular impingement and other hip joint pathologies. Hip traction is also used by college and professional athletes to help provide an optimal environment for training and recovery.

The science behind HipTrac is well established – long axis hip (femoral-acetabular) traction has been in use for more than 100 years.  Health care practitioners have performed manual traction to the hip joint as part of their routine diagnostics and treatment for conditions resulting in pain and decreased mobility of the hip joint. It is globally accepted and the most widely used manual therapy technique by all medical/osteopathic physicians and surgeons, physical therapists and chiropractors in clinical treatment of the hip joint. Multiple studies – summarized below – document the efficacy of long axis traction in pain reduction and increased mobility and the additional benefits of higher traction forces.

Abbott JH, et al., Manual therapy, exercise therapy, or both, in addition to usual care, for osteoarthritis of the hip or knee: a randomized controlled trial. 1: clinical effectiveness, Osteoarthritis and Cartilage (2013), https:// j.joca.2012.12.014

The Management of OsteoArthritis (MOA) Trial investigated the long-term effectiveness of: (1) an individualized manual therapy treatment program in addition to usual care; (2) a multi-modal, individualized, supervised exercise therapy program in addition to usual care; and (3) a combination of both programs in addition to usual care; compared with usual care only, for the management of pain and disability in adults with hip or knee OA. The results are consistent with those of Hoeksma et al., who found manual therapy, including the mandatory use of long axis traction, to be superior to exercise therapy for patients with hip OA. Hoeksma’s group found lasting treatment effects through 29 weeks, while this study found thru 52 weeks. While this trial was not intended to compare these two modes of therapy, the manual therapy protocols provided greater reductions in WOMAC scores than did exercise therapy. The exercise group also showed significant improvements in WOMAC scores, just not as much as manual therapy. Overall, all groups improved the most at 9 weeks and maintained significant improvements at 1 year.

HL, Dekker J, Ronday HK, et al. Comparison of Manual Therapy and Exercise Therapy in Osteoarthritis of the hip: a randomized trial. Arthritis Rheum. 2004;51(5):722-729

This randomized controlled trial compared the use of manual therapy and therapeutic exercises in patients with hip OA. The manual therapy group received traction of the hip joint, stretching techniques of shortened muscles surrounding the hip joint, and traction manipulation (high velocity thrust technique) in each limited position. The exercise group’s goal was to improve hip ROM, muscle length, and strength along with walking endurance. The outcomes for hip function (Harris Hip Score), ROM, and pain a measured by the visual analogue scale were compared for specific subgroups of hip OA depending on limited function, ROM, or level of pain. After 5 weeks of
intervention, the success rate (primary outcome) of manual therapy was 81% versus 50% for exercise therapy (odds ratio,1.92; 95% CI: 1.30-2.60). Manual therapy was found to be superior to exercise therapy in some patients with mild/moderate hip OA but was not shown to be any more effective than exercise in patients with highly limited function, ROM, or high levels of pain(severe OA). When intervention stopped, the improvements for in function for the exercise group declined after 5 weeks. However, improvement lasted up to 29 weeks for the patients in the manual therapy group.

Wright A, Abbot JH, Baxter D, Cook C. The ability of a sustained within-session finding of pain reduction during traction to dictate improved outcomes from a manual therapy approach on a patients with osteoarthritis of the hip. J Man Manip Ther. 2010;18(3): 166-172.

The objectives of this study were to: 1) determine the association of a within- session finding after traction of the hip with self-report of well-being, pain, and self-report of function at 9 weeks; and 2) to determine if the interactions between the within-session finding and the outcome measure are different between groups of patients with hip OA who receive and who do not receive manual therapy . Significant differences did exist in the global rating of change and pain in the manual therapy group vs the non-manual therapy group.

Vaarbakken, K. Superior effect of forceful manual traction mobilizations compared to standard mobilizations in treatment of painful hip hypomobility. Section for Physiotherapy Science, Department of Public Health and Primary Health Care. Faculty of Medicine, University of Bergen, Norway . 1-79.

This research compares long axis traction mobilization at standard and high forces to assess which is superior for improvements in pain and mobility . The group receiving graded traction mobilization forces up to 800 N experienced superior important clinical effects as compared to the other group receiving traction of much lesser forces. The results suggest that a physical therapy program including higher forces with manual traction are effective in reducing self-rated hip disability in primary health care.