The effects of military body armour on the lower back and knee mechanics during toe-touch and two-legged squat tasks

The comfort and functional performance of personal protective equipment for police officers: a systematic scoping review

This scoping review aimed to identify and summarise evidence on the comfort and functional performance of police officer personal protective equipment (PPE). The Arksey and O'Malley (2005) five-stage framework for scoping reviews was followed. PubMed, CINAHL, Scopus, and Web of Science were searched, and 35 articles were included in the review. The findings show that increased police PPE mass increases heart rate, metabolic energy expenditure, and perceived exertion in response to exercise. Unisex armour designs cause increased discomfort for females with larger bra sizes. PPE reduces joint-specific range of motion, with the design and location impairing movement more than mass. Jumping and sprinting performance is decreased with heavy PPE but unaffected by lighter protection, while agility is compromised with most forms of protection. Future research is needed on the fit and function of PPE for specialist police units, such as mounted police, along with further investigations on how fit can affect functional performance.

The immediate and prolonged effects of military body armor on the relative timing of thorax and pelvis rotations during toe-touch and two-legged squat tasks

Although military body armor is an effective life saver, it considerably loads more weight on the warfighters, increasing the risk of musculoskeletal injury. This study investigated the immediate and prolonged effects of wearing body armor on timing aspect of lumbo-pelvic coordination during the toe-touch (TT) and two-legged-squat (TLS) tests. A cross-over study design was used wherein twelve asymptomatic and gender-balanced individuals completed two experimental sessions with and without body armor. A session included two similar sets of tests, before and after exposure to a treadmill walk, containing a TT and a TLS test with ten cycles of fast bending and return. Reflective markers were attached on the participants to capture the kinematics of body segments in conjunction with a motion capture system. The mean absolute relative phase (MARP) and deviation phase (DP) between the thorax and pelvis were calculated for each test. The pre-walk MARP in the return was significantly larger with versus without body armor (p = 0.022), while there were no significant effects of body armor on the other outcome measures. In addition, the pre-walk MARP and DP in the bending and return, as well as the walk-induced changes in the MARP in the bending phase were significantly larger in TLS versus TT (p < 0.026). Therefore, using a body armor immediately made the lumbo-pelvic coordination less in-phase during return, but no prolonged effects were found. Further investigation is necessary to specify chances wearing a body armor increases the risk of musculoskeletal injuries in the lower back and lower extremities joints.

The effects of body armour on mobility and postural control of police officers

BACKGROUND

Police officer use of Individual Light Armour Vests (ILAVs) is increasing due to potential occupational hazards that include blunt trauma, stabbing, and light calibre bullets. It is unclear how addition of this extra load will affect the officer's mobility or postural control.

OBJECTIVES

The aim of this study was to determine the effects of various ILAVs on the mobility and postural control of police officers when compared to wearing their normal station wear.

METHODS

A prospective, within-subjects, repeated measures study was conducted in which officers wore one of three different ILAV variants or normal station wear (N) and acted as their own controls. Officer mobility was assessed via the Functional Movement Screen (FMS) and postural sway (including total sway, average sway velocity, medial-lateral velocity, anterior-posterior velocity, and total excursion area) via force plate.

RESULTS

Significant differences were found between ILAV or N conditions in various components of the FMS, including right Straight Leg Raise, left shoulder mobility, and both right and left quad rotary stability. No significant differences were found in any of the balance measures between these conditions.

CONCLUSION

It appears ILAVs can significantly affect police officer mobility and therefore may contribute to injury risk and decreased ability to complete occupational tasks, though this should be weighed against protective benefits. ILAVs should therefore be carefully selected to minimise injury risk without detracting from occupational performance.

Lumbar contribution to the trunk forward bending and backward return; age-related differences

Age-related differences in lumbar contribution to the trunk motion in the sagittal plane were investigated. Sixty individuals between 20-70 years old in five gender-balanced age groups performed forward bending and backward return with slow and fast paces. Individuals older than 50 years old, irrespective of the gender or pace, had smaller lumbar contribution than those younger than this age. The lumbar contribution to trunk motion was also smaller in female participants than male participants, and under fast pace than under the slow pace. Age-related differences in lumbar contributions suggest the synergy between the active and passive lower back tissues is different between those above and under 50 years old, differences that are likely to affect the lower back mechanics. Therefore, detailed modelling should be conducted in future to find the age-related differences in the lower back mechanics for tasks involving large trunk motion. Practitioner Summary: Lumbar contribution to the sagittal trunk motion was observed to be smaller in individuals above 50 years old than those below this age. This could be an indication of a likely change in the synergy between the active and passive lower back tissues, which may disturb the lower back mechanics.

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

BACKGROUND

The law enforcement officer profession requires performance of arduous occupational tasks while carrying an external load, consisting of, at minimum, a chest rig, a communication system, weaponry, handcuffs, personal protective equipment and a torch. The aim of this systematic review of the literature was to identify and critically appraise the methodological quality of published studies that have investigated the impacts of body armour on task performance and to synthesize and report key findings from these studies to inform law enforcement organizations.

METHODS

Several literature databases (Medline, CINAHL, SPORTDiscus, EMBAS) were searched using key search words and terms to identify appropriate studies. Studies meeting the inclusion criteria were critically evaluated using the Downs and Black protocol with inter-rater agreement determined by Cohen's Kappa.

RESULTS

Sixteen articles were retained for evaluation with a mean Downs and Black score of 73.2 ± 6.8% (k = 0.841). Based on the research quality and findings across the included studies, this review determined that while effects of body armour on marksmanship and physiological responses have not yet been adequately ascertained, body armour does have significant physical performance and biomechanical impacts on the wearer, including: a) increased ratings of perceived exertion and increased time to complete functional tasks, b) decreased work capability (indicated by deterioration in fitness test scores), c) decreased balance and stability, and d) increased ground reaction forces.

CONCLUSIONS

Given the physical performance and biomechanical impacts on the wearer, body armour should be carefully selected, with consideration of the physical fitness of the wearers and the degree to which the armour systems can be ergonomically optimized for the specific population in question.

Lumbopelvic rhythm in the sagittal plane: A review of the effects of participants and task characteristics

OBJECTIVES

Abnormalities of lumbopelvic coordination have been suggested to relate to risk of developing low back pain. The objective of this study is to review and summarize the findings of studies that have implemented and reported on lumbopelvic rhythm during trunk forward bending and backward return.

METHODS

The PUBMED and CINAHL databases were searched for studies related to LPR using appropriate keywords. The references of each study from the database search were further investigated to identify any missed study.

RESULTS

The findings includes results related to lumbopelvic rhythm, and how it varies due to participant characteristics such as age, gender, and presence of low back pain as well as due to variations in the experimental procedures such as pace of motion, presence of external load, and muscle fatigue.

CONCLUSION

In general, the magnitude of lumbar contribution is smaller in people with low back pain, in the elderly and females, as well as with greater pace of motion, but is larger with greater external load or back muscle fatigue. The compiled data in this review are expected to serve as a foundation for implementation of this kinematic-based measure in the conduct of future research.

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

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 military body armour on the lower back and knee mechanics during box drop and prone to standing tasks

Modern day body armour (BA) has been successful at increasing survivability from previously lethal explosives; however, it has been suggested to reduce warfighter's performance and increase risk of injury. Joint biomechanics have a foremost impact on performance and risk of injury. The immediate and prolonged effects of wearing BA on biomechanics of the lower back and knee during box drop (BD) and prone to standing tasks were investigated. The immediate effects of BA on both tasks were an increase of ≥4% (p ≤ 0.02) in temporal task durations and a decrease of ~1.66 N/kg (p = 0.03) in normalised peak ground reaction force for the BD test. The prolonged duration of walking with BA (i.e. 45 min) was not found to cause more changes in our measures than walking without BA. Quantitative data related to the effects of BA are important for risk assessment and mission design such to reduce the risk of injury without compromising performance. Practitioner Summary: The effects of wearing military body armour (BA) on biomechanics of the lower back and knee were investigated. Though wearing BA was found to affect some biomechanical measures related to performance, the prolonged effects of exposure on our measures were the same whether or not the participants wore BA.

Lumbopelvic rhythm during trunk motion in the sagittal plane: A review of the kinematic measurement methods and characterization approaches

Lumbopelvic rhythm during trunk forward bending and backward return has been widely investigated to have a better understanding of the pattern of trunk motion, as used in research on low back disorders. Considerable differences in the methods used to measure, and approaches used to characterize the lumbopelvic rhythm hinder the integration of findings of those studies for further research in the future. Thus, the purpose of this review was to summarize the methods for kinematic measurement as well as their characterization approaches for the lumbopelvic rhythm. PUBMED and CINAHL databases were searched for relevant studies. Several types of instruments were found to be used in the reviewed studies, mostly using markers or sensors, which were placed on different parts of spine, with different definitions to measure the lumbar and pelvic motion. Also, various characterization approaches were found to be used, of which some related to the magnitude, while the others to the timing aspects of lumbopelvic rhythm. Such a characterization was either qualitative or quantitative. In addition, the specified characterization approaches were applied on a sample of trunk kinematics data from our lab to demonstrate differences in the outcomes of these approaches.