Martin Mc Intyre: The HRIG – Specificity and the mechanism of hamstring injuries
Background
Martin Mc Intyre has experience of working in high performance sport and leading and promoting excellence to deliver in world-class environments within elite teams. Currently, he is the director of the Sports Injuries and Sports Medicine Clinic. He works with Mayo Senior Football team and is the sports medicine lead with Mayo FA. His education has entailed:
PhD – Hamstring Muscle Strength Assessment and the Association with Injury Risk in Gaelic Football – John Moore’s University Liverpool – January 2023
M.Med.Sci - Sports Medicine, Sheffield Hallam University and University of Sheffield – July 2006
MSc - Physiological Profiling of Gaelic footballers, Institute of Technology Tralee, Co Kerry, Ireland - June 2003
BSc (Hons) - Sports Science, John Moore’s University, Liverpool - July 1997
Higher Education Diploma - Science and Football, John Moore’s University, Liverpool - July 1996
He is the founder of a new device the HRIG where they currently work with premier league football teams, English championship sides and the English footballers at St Georges Park. The HRIG is also installed at various clinics, performance centres and universities throughout Ireland. Hamstring injury is currently his main area of research.
Research Project
Hamstring strain injury (HSI) is fast becoming a literal pain in the “Posterior’ of both medical and performance staff. It is the most common injury in field sports.
The rate of HSI in Gaelic football is 1.5-2.6 times higher than the rate of HSI sustained in professional soccer (4.77 & 0.51 injuries per 1000h) (Ekstrand et al., 2016), rugby (5.6 & 0.27 injuries per 1000h) (Brooks et al., 2006) and American football (2.7 & 0.47 injuries per 1000h) (Elliott et al., 2011). Running is the main mechanism and accounts for 48%-81% of all hamstring injuries (Roe et al., 2018; Wilson et al., 2007; Askling et al., 2013). HSI injury generally occurs in either late swing phase or early stance (Chumanov et al., 2011, Chumanov et al., 2012, Orchard et al., 2012, Schache et al., 2010, Yu et al., 2008, Heiderscheit et al., 2005, Schache et al., 2009) as this is where the greatest stress is placed on the hamstrings. It is required to tolerate large forces between 10.5-26.4 N.Kg-1(Kenneally-Dabrowski et al., 2019). Emanating originally from the start of a PhD some 7 years ago at Liverpool John Moores University and with some further research and product development from a sports engineering team at Sheffield Hallam University has led to the development of the HRIG. This involves a test to examine the mechanism of HSI while it can also be used to rehab, prehab and strengthen players in late swing/early stance to protect them from injury.
The specificity of the test position places the participant in an upright posture and they hold onto a vertical bar for support which is positioned 1m from the ground. The knee of the un-tested limb is then placed on a bench in 200 of hip extension. The tested limb is then flexed to 300 at the knee. The heel is placed in a load cell and the isometric force is measured at this point. Both force and torque are recorded for all repetitions.
First of all moderate-high levels of intra and inter-rater reliability ensure measurements are highly reliable and repeatable. The bilateral testing position on the HRig system has shown high inter-rater reliability ICC (CI 95%) of 0.86 (CI 0.74-0.92) with the typical error of 19N (14-27N). Unilateral isometric testing showed high Interrater reliability ICC (CI 95%) of 0.92 (CI 0.85-0.96) with the typical error of 23N (18-34N) (Mc Intyre, 2023)
Secondly, the similarity of the test position to the mechanism of injury or the most venerable phase of the gait cycle has indicated that these positions of testing better identifies those with residual strength deficits following hamstring strain injury, compared to nordic fall eccentric strength testing (Mc Intyre et al., 2022). Furthermore, they also identify deficits in players with previous HSI and those who sustain future HSI during the playing season (Mc Intyre et al., 2024).
Thirdly, the device has been highly correlated with biceps femoris fascicle length this serves as a useful measure of protecting and dosing players in terms of reducing prospective and future injury. Targeted isometric strength training has also been developed to strengthen players in the sprint position. This can be achieved safely and progressively involving both pulling/pushing and quasi isometric muscle function.
In Summary:
Be specific – mimic the mechanism of injury when undertaking hamstring assessment to maximise sensitivity.
Ensure methodologies have a high intra- and inter-rater reliability.
This method of assessment can help identify future risk of future hamstring injury.
HRIG can be useful in protecting players for future HSI due to time spent under tension/load in the vulnerable position of late swing and early stance.