Biomedical subjects

Laurence E Holt

Publications and source records attributed to Laurence E Holt.

4 recordsLinked to original sources

PubMed2006

A research pilot project to test the efficacy of current pedorthic practices in the Canadian Forces.

Impact loading is a major factor in the high prevalence of musculoskeletal injuries among military personnel during operational tasks. One of the therapeutic purposes of a pedorthic approach is to attenuate impact load through footwear and supportive device cushioning. The following research pilot project attempts to investigate this relationship. Vertical acceleration was collected at the fourth lumbar level in 30 members of the Canadian Forces (CF) during two ladder descents on a CF warship. Body weight, time of descent, and a description of footwear and any additional supportive appliances were also collected. None of the evaluated variables were significantly different between members wearing standard issue footwear and medically prescribed footwear and supportive devices. Although the results of this research pilot must be viewed with caution, the preliminary findings of this pilot tends to suggest that the current pedorthic practices may not effectively reduce peak impact forces at the fourth lumbar level of the spine among CF personnel during a selected naval activity.

Canada↗

PubMed2006

Assessing human movement with accelerometry.

The methods for measuring and evaluating human movement have advanced rapidly over the past 2 decades. The use of smaller, lighter, more powerful personal computers, digital video cameras and miniature, portable accelerometers have allowed the health professional, engineer, sports coach and scientist to very precisely record and quantify human movements on the sports field, in the business office, industrial setting and in the home. Most human motion analysis systems have evolved to meet the particular needs of the user. One such system that has developed over the past ten years in the Sport Science Laboratory at Dalhousie University is the Padlog series of accelerometer systems. This paper will discuss the development the Padlog systems at Dalhousie.

Acceleration↗

PubMed2005

The etiology of low back pain in military helicopter aviators: prevention and treatment.

Low back pain (LPB) is a major health problem among military rotary-wing aircrews worldwide. In order to define the etiology and propose remedies to LBP in helicopter aviators a review and critique of the literature was conducted. In-flight sitting posture and vibration generated by the aircraft were identified as high risk factors for LBP. Consequently, researchers recommended ergonomic modifications to the crew stations. The efficacy of these technical interventions has not been proven. As well, these design changes are not financially practical. Following an in depth kinesiological analysis of the physical demands of this type of flying, and preliminary experimentation, an alternative aeromedical approach focusing on the aircrew rather than the craft is presented. The authors propose a set of flight-specific exercises that might effectively deal with this problem. A thorough testing of this approach is envisioned.

Aircraft↗

PubMed2003

Electromyographic comparison of the upper and lower rectus abdominis during abdominal exercises.

The objective of this pilot study was to determine the effect of 6 different abdominal exercises on the electrical activity of the upper rectus abdominis (URA) and lower rectus abdominis (LRA). Eight healthy, adult volunteers completed 6 random abdominal exercises: curl up, Sissel ball curl up, Ab Trainer curl up, leg lowering, Sissel ball roll out, and reverse curl up. Action potentials were recorded and analyzed from the URA and the LRA using surface electromyography (EMG) during a 2-second concentric contraction. The average normalized data were compared between the URA and the LRA in order to determine the behavior of the different muscle sites and between exercises in order to determine which exercises elicited the highest EMG activity. There were no significant differences (p > 0.05) between the EMG activity of the URA and LRA during any exercise. There were no significant interactions between subject and muscle site or between exercise and muscle site. Significant differences were found among the 6 exercises performed, and due to the interaction between subject and exercise performed. Both the URA and the LRA recorded significantly higher mean amplitudes during the Sissel ball curl up than during all other exercises. In addition, the curl up, Sissel ball curl up, and Ab Trainer curl up had significantly higher normalized EMG activity in both muscle sites than the reverse curl up, the leg lowering exercise, and the Sissel ball roll out. The curl up and the Ab Trainer curl up exercises were not significantly different in terms of their normalized EMG activities for both the URA and the LRA.

Action Potentials↗