Maximal manual stretcher carriage: performance and recovery of male and female ambulance workers

Abstract

The effects of a maximal duration stretcher carriage on heart rate (HR), lactate concentration, hand steadiness and hand-grip strength were studied up to 72 h post-exercise in 17 male and 15 female military ambulance personnel. Using both hands for transport, the participants walked on a treadmill ergometer at a speed of 4.5 km/h. Force measurements at the handlebars yielded mean loads of 245 N (25 kg) on each side. Each step on the treadmill induced additional force oscillations with peak forces up to 470 N corresponding to 130% (women) and 98% (men) of maximal voluntary contraction (MVC). In the males the maximal transport time was about twice the time in women (mean +/- SD: 184 +/- 51 s vs. 98 +/- 34 s). These differences had no significant effect on HR and lactate values. The same applies to hand steadiness, which showed only a transient deterioration immediately after exercise. In contrast to these parameters, substantial differences were seen in hand-grip strength recovery. Immediately after exercise, maximal hand-grip strength decreased by 150 N (25% MVC) in the males vs. 50 N (14%) in the females. Irrespective of gender, individuals with larger hand-grip strength and longer carriage durations (range 120 s-280 s) showed the slowest strength recoveries (up to 72 h) as compared to 1 h of recovery in participants with short transport durations (range 27 s-120 s). These findings suggest that the increasing number of eccentric strains during uninterrupted stretcher carriage induces cumulative muscle damages that may require some days for complete recovery.

Combined Physiological and Anthropometrical Databases as Ergonomic Tools

“…Even if metric problems actually do not occur at a workplace, the strength demands which take into consideration male and female percentile values may prevent ineffective personnel assignments. As an example, there is the manual stretcher transport which is an elementary task of ambulance and rescue 366 Combined Physiological and Anthropometrical Databases as Ergonomic Tools services: The sustained hand-grip contraction and the eccentric strains during the transport require large hand-grip forces by ambulance personnel (Leyk et al, 2006a(Leyk et al, , 2006bRice et al, 1996;von Restorff, 2000). With regard to pre-employment screening, von Restorff (2000) proposed to consider only applicants whose hand-grip strength on the weaker side exceeds 334 N.…”

“…and Exercise Physiology, Germany 2) German Sport University Cologne, Department of Physiology and Anatomy, Germany 3) Research Group Physiological Anthropology, University of Kiel both men and women (Bhambhani and Maikala, 2000;Leyk et al, 2006aLeyk et al, , 2006bRice et al, 1996). Thus, strength measurements are also necessary for pre-employment screening and selection.…”

The Physical Fitness Effects of a Week-Long Specialist Tactical Police Selection Course

“…These measures were repeated at the same time daily as a measure of cumulative fatigue. Grip strength was selected as an outcome measure due to its association as a marker of fatigue [ 11 , 12 ] and association with elements of tactical performance in these populations [ 13 ].…”

Soldier Load Carriage, Injuries, Rehabilitation and Physical Conditioning: An International Approach

“…However, with an increased risk of injury and no additional improvements in load carriage performance found when sessions were greater than four per month [110], the recommendation is that load carriage-specific sessions are conducted no more than once every 10 to 14 days, since a further increase in frequency will typically not increase performance but may increase the risk of injury [30]. This reasoning is also strengthened by the observation of a slow recovery of neuromuscular function in the trunk and limbs up to 48-72 h after a load carriage bout [11,111,112]). For example, in a study by Leyk et al [112], military ambulance workers performed a maximal stretcher transport with a mean load of 25 kg on each side and wearing 10 kg of standard military clothing.…”