Injury reduction in the forcesFor the last ten years, Dr James Bilzon, Director of Studies for the Sport and Exercise Medicine Programme at the University of Bath, has worked closely with the Army Recruiting & Training Division (ARTD) to reduce the incidence of musculoskeletal injuries (MSI). The research has proven successful with a range of trainees, including Paratroopers, new trainees with lower fitness levels and female recruits.

A number of modern occupations are inherently physically arduous and can result in significant levels of morbidity and mortality. This is particularly true for people employed in the uniformed services, such as the army, fire and rescue services and other occupations where there is exposure to challenging scenarios and environments.

Typically, these would include hot environments, fire-containing compartments and hypoxic storage facilities. Strategic evidence-based approaches are necessary to prevent and manage the incidence and severity of musculoskeletal injuries (MSI) and associated illnesses among personnel during training and operational duties.

There were also deaths and hospitalisations due to Exertional Heat Stroke (EHS) during summer military training, while relatively rare, it was suggested that a strategic approach to the selection, training and care of recruits should be fully investigated. Following a peak in discharges due to musculoskeletal injuries in 2000, the ARTD began to investigate the problem, and in 2002, employed Dr James Bilzon as Senior Scientific Officer to lead a strategic medical research group.

Early research demonstrated that the ARTD medically discharged more than 1000 trainees each year, with more than 60% of these directly attributable to overuse lower limb musculoskeletal injuries. Vulnerable groups appeared to be those with lower levels of aerobic fitness, those engaged in the most arduous training regimes and female trainees. Indeed, discharges due to musculoskeletal injuries rates peaked in 2001 for male trainees (25 per 1000) and female trainees (95 per 1000). A series of further studies demonstrated that gender, aerobic fitness and training location, as well as a number of lifestyle factors, such as smoking and physical activity, were independent risk factors for musculoskeletal injuries and lower limb stress fractures. These findings were used to drive the subsequent exploratory research and intervention studies.

A number of in-depth, laboratory-based investigations have since been conducted to assess the impact of various stressors on the health and function of military personnel, the physical demands of military training and the role of nutritional supplements in enhancing physiological function during simulated military tasks. However, it is the controlled intervention studies, which have now been implemented as British Army training policy, which have had the greatest immediate and measurable impact.

1. Gender Streaming

Research showed a higher incidence of injury in females than males when they formed a minority proportion of mixed-gender platoons. Medical discharge (MD) due to injury was at the rate of 95 in 1000 trainees, compared to 25 per 1000 in males. The formation of single sex platoons, offering improved training techniques and female commanders, was piloted. After a 12-month evaluation, women were achieving the required level of operational fitness, with a huge reduction in MD, which now stands at the same rate as their male colleagues. To date, the British Army is believed to be the only army in the world to introduce female-only training regimes.

2. Soldier Preconditioning Course (SPC)

Trainees in the bottom 20% for aerobic fitness were shown to be more than twice as likely to be medically discharged and over than six times more likely to be referred to a physiotherapist with a limiting musculoskeletal injuries. In light of this evidence, ARTD were advised to introduce a three-week SPC for the least fit infantry trainees. This consisted of frequent, moderate intensity, low impact physical training. On average, trainees lost 2.6 kg in body mass and improved in all aspects of physical fitness. In particular, aerobic fitness improved by around 7% over the course of the three-week programme. The incidence of discharges due to musculoskeletal injuries during subsequent infantry training was significantly lower in the SPC (4.8%) compared to the control group (9.4%).

3. Parachute Regiment Training

Training to be an elite Parachute Regiment soldier is widely regarded as the most arduous in the British Army. Pass out rates were very low – around 43%, and MD was high, at 14.4%. An in-depth study resulted in a complete overhaul and extension of the progressive 26-week training programme, including the introduction of a fourth meal in the evening and a more rigorous selection procedure to ensure the best candidates were joining training at the front end. First time pass-out rates increased to 58% and discharges due to musculoskeletal injuries decreased to 5.1%.

4. Exertional Heat Stroke (EHS)

Exertional Heat Illness (EHI), and occasionally EHS, occur when humans are required to function in unaccustomed hot/humid environments, but around 100 cases a year used to occur during arduous military training in the UK summer. Measurement of core body temperature responses demonstrated that simple changes could, at least theoretically, markedly reduce the incidence of EHI during training. This proved to be the case at the Royal Military Academy Sandhurst (RMAS).

Results overview

Since 2002, Dr Bilzon’s programme of work has contributed to a reduction in medical discharges due to musculoskeletal injuries from 25 to 10 per 1000 among male trainees, and from 95 to 25 per 1000 among female trainees. Pre-conditioning courses for the less fit trainees at the point of entry have been making a significant improvement in reducing the risk of injury later in training. By helping reduce the incidence and severity of EHI, this programme has also contributed to a substantial increase in the number of trainees completing training and avoiding potential career or life threatening injuries.

Broadening the impact

The benefits of combining occupational physiology research in the lab, with intensive testing in the field, have been proven for the British Army. Studies in low oxygen environments, such as storage facilities used by the British Library, have helped to develop new working practices, and Dr Bilzon continues this work in other sectors, as diverse as the fire service and grocery retailing, where operational fitness and injury rates can be improved through better training techniques.