The effects of military body armour on trunk and hip kinematics during performance of manual handling tasks

Abstract

Musculoskeletal injuries are reported as burdening the military. An identified risk factor for injury is carrying heavy loads; however, soldiers are also required to wear their load as body armour. To investigate the effects of body armour on trunk and hip kinematics during military-specific manual handling tasks, 16 males completed 3 tasks while wearing each of 4 body armour conditions plus a control. Three-dimensional motion analysis captured and quantified all kinematic data. Average trunk flexion for the weightiest armour type was higher compared with control during the carry component of the ammunition box lift (p < 0.001) and sandbag lift tasks (p < 0.001). Trunk rotation ROM was lower for all armour types compared with control during the ammunition box place component (p < 0.001). The altered kinematics with body armour occurred independent of armour design. In order to optimise armour design, manufacturers need to work with end-users to explore how armour configurations interact with range of personal and situational factors in operationally relevant environments. Practitioner Summary: Musculoskeletal injuries are reported as burdening the military and may relate to body armour wear. Body armour increased trunk flexion and reduced trunk rotation during military-specific lifting and carrying tasks. The altered kinematics may contribute to injury risk, but more research is required.

The effects of body armour on the power development and agility of police officers

“…Peak forces affecting the musculoskeletal system may be higher during explosive movements such as the counter movement jump when officers are wearing body armour than when they are wearing normal station wear, and it is possible this might increase injury risk for the lower limb. Wearing heavier, military styled body armour (6.4-10.8kg), has been shown to increase ground reaction forces, time to complete tasks, increase trunk flexion and decrease trunk rotation (Phillips, Shapiro, and Bazrgari 2016;Lenton et al 2016). As with military personnel, strength training along with education and training on landing techniques when wearing loads may be of benefit to police officers required to wear ILAVs.…”

The impact of body armor on physical performance of law enforcement personnel: a systematic review

“…Specifically, six studies were from the US [ 23 , 28 – 32 ], five publications were from Australia [ 5 , 14 , 33 – 35 ], two from New Zealand [ 3 , 36 ], one from India [ 37 ], one from Poland [ 38 ], and one from the UK [ 39 ]. Three distinct subject populations were represented, consisting of university students ( n = 7) [ 29 , 31 – 35 , 39 ], LEO ( n = 4) [ 3 , 5 , 14 , 36 ], and military personnel ( n = 5) [ 23 , 28 , 30 , 37 , 38 ]. Additionally, ten of the publications studied only males [ 3 , 5 , 14 , 33 – 39 ] and six included both males and females [ 23 , 28 – 32 ].…”

“…The mean ± SD CAS, derived from critical appraisal of the methodological quality of each included study, was 73.2 ± 6.8%, ranging from 60.7% [ 35 ] to 85.7% [ 36 ]. This mean indicates that most studies were of at least ‘good’ (62.5%) methodological quality.…”

“…When applying the Downs and Black protocol for critical appraisal of each publication, Questions 1–14, concerning how data was reported, generally scored highly across all studies. Low external validity scores (Questions 11–13) were attributed to those studies which did not recruit participants from a tactical population [ 29 , 31 – 35 , 39 ]. Additionally, one study recruited subjects from a population of military personnel (US Airborne Infantry Soldiers) that had been trained at a level substantially beyond their peers (US Infantry Soldiers).…”

“…Since neither level of protection nor cost are enhanced by systems with potential to improve mobility [49], effective body armour has been repeatedly shown to be ergonomically detrimental, specifically with respect to trunk posture [3, 30–32, 35]. GRF [3, 32, 36] universally deteriorated when participants in the included studies were wearing body armour.…”