Neck loading in high performance combat pilots during aerial combat manoeuvres and specific neck strengthening exercises

Background: Neck pain and injury is a common occurrence in high performance combat pilots (HPCP) around the world. The cause of this has been attributed to exposure to the unavoidable high mechanical loading related to the neck being positioned in non-neutral head postures whilst being exposed to moderate to high +Gz levels. Specific neck conditioning exercises have been proposed as being a possible method to decrease the incidence of neck pain and injury in this population. However, there has been sparsely published research examining the suitability of selected exercises for HPCP who participate in regular aerial combat manoeuvres (ACM)

Head motion in overarm throwing for children with varying levels of motor proficiency

The overarm throw has been classified as a fundamental motor skill that is the basis for a number of more complex sporting skills. There are a number of developmental stages over which a child progresses to the mature form of the skill. Control of the overarm throw, especially towards a target is very dependent on visual and vestibular information for successful execution. The quality of the information is, in tum, dependant on the head movement of the performer during the execution of the skill. It has been reported that head angular velocities above 350 degrees/second result in a degradation of useful visual and vestibular information and as such, a loss in control of the performed skill. The purpose of this study was to investigate head movement in children while they performed an overarm throw towards a forward facing target. The study also investigated the possible relationship between motor proficiency of the thrower and their head movement. Three hypotheses were investigated. These included: 1. The head is stabilised during the throw. 2. The head is stabilised throughout the performance until close to ball release where it will move with the trunk as part of the \u27kinetic chain\u27. 3. Subjects with lower levels of motor proficiency stabilise their head Jess over the whole performance when they are compared to subjects with higher motor proficiency levels. Ten, ten-year-old children of mixed gender and varying levels of motor proficiency participated in the study. Subjects were video recorded performing an overarm throw towards a forward facing target. Their throwing proficiency was assessed using a standard motor test. The video of the throw was digitised and analysed to produce angular velocities profiles of the head and trunk about different reference axes. It was found that all of the subjects except one stabilised their head throughout the whole throwing performance. It was also found that the subjects stabilised their head intentionally and independently despite large trunk angular velocities near the end of the performance. These findings support hypotheses l and 2. No significant relationship was found between motor proficiency and head movement. Thus hypothesis 3 remained unsupported. Further research with a larger sample size and changes to the motor proficiency-testing regime are required to investigate the possible relationship between motor proficiency and head movement

Predicting neck pain in Royal Australian Air Force fighter pilots

Objective: Fighter pilots frequently report neck pain and injury, and although risk factors have been suggested, the relationships between risk factors and neck pain have not been quantified. The aim of this study was to identify personal and work behaviors that are significantly associated with neck pain in fighter pilots. Methods: Eighty-two Royal Australian Air Force fighter pilots were surveyed about their flying experience, neck pain prevalence, and prevention. Multinomial logistic regressions were used to fit models between pilots\u27 neck pain during and after flight and a range of personal and work characteristics. Results: In-flight neck pain was very weakly, yet positively associated with flight hours. Duration of postflight pain was positively associated with the weekly desktop work hours and the sum of preventative actions taken in flight. The duration pilots were considered temporarily medically unfit for flying was positively associated with pilots\u27 age and their weekly desktop work hours. Discussion: The risk factors identified by the current study should guide neck pain prevention for fighter pilots. In particular, reducing desktop working hours as well as incorporating specific neck-strengthening exercises and in-flight bracing actions should be considered by agencies to help alleviating neck pain in their pilot

The effect of body armor on performance, thermal stress, and exertion : a critical review

Armed forces worldwide utilize some form of body armor as part of their personal protective system. This is particularly essential in recent times because of the increased sophistication of weapons employed during modern warfare and the advent of unconventional combat methods (such as the increased use of improvised explosive devices). There is some evidence to show, however, that the usage of military body armor impairs physical performance. This review of the literature will focus on the effect of body armor on the performance of, and physiological and subjective responses during, military-style physical tasks. Because of the paucity of research investigating body armor, this review will also draw upon more generalized personal protective clothing and equipment literature from a range of physically demanding occupations (i.e., firefighting and other emergency services). The review will conclude with suggested directions for future research in this area

Task-specific effects of modular body armor

Eleven recreationally active males performed 11 circuits of military work, wearing torso armor on one occasion, and full armor on another. Performance was measured by the time taken to complete individual tasks, and the overall time to completion (TTC) for each circuit. Heart rate, intestinal temperature, ratings of perceived exertion (RPE), and thermal sensation were recorded after each circuit. Participants’ circuit TTC was no different between conditions; however, specific tasks were differentially impeded by the two armor configurations. Vaulting and crawling were significantly slower (0.28 ± 0.06 and 0.55 ± 0.26 seconds) in full armor; however, box lifting and shooting weresignificantly slower (0.36 ± 0.18 and 0.86 ± 0.23 seconds) when wearing torso armor. Heart rate and core temperature were significantly higher during the full armor trial (5 ± 1 beats min-1 and 0.22 ± 0.03°C). Similarly, RPE and thermal sensation were significantly higher (1 ± 0 and 0.5 ± 0.0) during the full armor condition. Military tasks were differentially impaired by the armor configurations used, which suggests a need to explore role-specific armor for military personnel. Physiological and perceptual responses were elevated in full armor, which could be exacerbated during longer periods of work or in hot conditions

BACK STRESS AND ASSISTANCE EXERCISES IN WEIGHTLIFTING

The purpose of this study was to test the suitability of selected assistance exercises to strengthen the low back for the Olympic lifts in high level weightlifters. Four subjects were filmed by a five-camera Motion Analysis system operating at 120Hz completing both of the Olympic lifts (Snatch and Clean) and four assistance exercises (Romanian Oeadlift (ROL), Bent-over Row (BOR), Clean Pull Oeadlift (CPO), and Good Morning (GM)). Peak Erector Spinae Force (ESF) and L5/S1 compressive and shear force (L5/S1 CF and L5/S1 SF respectively) were calculated via a top-down inverse dynamics model. Comparisons between the lifts were made using a one-way ANOVA with repeated measures. It was found that the CPO produced higher ESF than the Snatch but this exercise also produced very high L5/S 1 CF and L5/S1 SF. The Clean also displayed a higher ESF than the Snatch. When normalising the data to bar weight, the BOR and GM was shown to potentially produce high ESF but coaches should consider the possibility for these exercises to produce low back injury

A comparison of methods to calculate the optimal load for maximal power output in the power clean

The aim of this study was to compare three calculation methods to determine the load that maximises power output in the power clean. Five male athletes (height=179.8 10.5cms, weight 91 .8 8.8kg, power dean 1RM = 117.0 20.5kg) performed two per cleans at 10% increments from 50% to 100% of 1RM. Bar displacement data was collected using a Ballistic Measurement System (BMS) and vertical ground reaction force (VGRF) data was measured by a Kistler 9287B Force Plate. Power output was calculated for BMS (system mass), BMS (bar mass) and VGRF/BMS system mass. Optimal load was determined to be 70% for the BMS (system mass) and VGRF BMS (system mass) methods and 90% for the BMS (bar mass) method. Sports scientists should be aware of the technical issues underlying these findings due to the practical ramifications for athlete testing and training.<br /

An electromyographic comparison of neck conditioning exercises in healthy controls

The purpose of this study was to compare surface electromyography (EMG) activation levels of selected neck muscles for two common neck-training modalities (Thera-Band and Cybex). Seventeen asymptomatic subjects (eight men and nine women) with a mean age 23.4 years were recruited. EMG activation normalized to maximal voluntary isometric contraction (MVIC) was measured with subjects performing exercises with green, blue, and black Thera-Bands and 50%, 70%, and 90% of 3RM for the Cybex modality. Four variables were used to depict exercise intensity: average and peak EMG activation in the concentric and eccentric phases. Significant differences (P &lt;= 0.05) in EMG activation were evident when comparing intensities of the Cybex modality with each other and when comparing the Cybex intensities with Thera-Band intensities in most cases. Minimal differences were found among differing intensities of Thera-Band. Thera-Band exercise resulted in low-level EMG activation (range, flexion 3.8-15.7% MVIC; range, extension 20.2-34.8% MVIC); therefore, such exercise may be useful in rehabilitation programs. Cybex exercise (range, flexion 20.9-83.5% MVIC; range, extension 40.6-95.8% MVIC) may be useful for occupation-related injury prevention. However, exercise prescription should be undertaken with care as the mechanical loading on passive spinal structures is unknown.<br /

Validity of wearable technology to measure peak impact during high-intensity treadmill running

The purpose of this study was to identify the validity of an upper-body mounted accelerometer to measure peak acceleration during high-intensity treadmill running. A twelve camera motion analysis (MA) system was used as the criterion measure with markers placed on and close to the accelerometer. Ten peak impacts per participant were compared (n = 390). All accelerometer values were significantly different between the MA unit and T6 reflective marker’s acceleration data. Smoothing accelerometer data at 8 and 6 Hz provides an acceptable indirect measure of peak impact acceleration performed during high-intensity running. Therefore, smoothing algorithms should be incorporated into the commercially available software that the devices are supplied with

A COMPARISON OF METHODS TO CALCULATE THE OPTIMAL LOAD FOR MAXIMAL POWER OUTPUT IN THE POWER CLEAN

The aim of this study was to compare three calculation methods to determine the load that maximises power output in the power clean. Five male athletes (height=179.8 10.5cms, weight 91.8 8.8kg. power clean 1RM = 117.0 20.5kg) performed two power cleans at 10% increments from 50% to 100% of 1RM. Bar displacement data was collected using a Ballistic Measurement System (BMS) and vertical ground reaction lorce (VGRF) data was measured by a Kistler 9287B Force Plate. Power output was calculated for BMS (system mass), BMS (bar mass) and VGRF/BMS system mass. Optimal load was determined to be 70% for the BMS (system mass) and VGRF 8MS (system mass) methods and 90% for the BM3 (bar mass) method. Sports scientists should be aware of the technical issues underlying these findings due to the practical ramifications for athlete testing and training