3D-Printed Tourniquets Used at the Battlefront in Ukraine: A Pilot Study.

BACKGROUND: The war in Ukraine urged a need for prompt deliv- erance and resupply of tourniquets to the front. Producing tour- niquets near the battlefront was a feasible option with respect to resupply and cost. METHODS: A locally produced 3D-printed tourniquet (Ukrainian model) from the "Tech Against Tanks" charity was tested against commercially available and Committee of Tactical Combat Casualty Care (CoTCCC)- recommended tourniquets (C-A-T™ and SOF™TT-W). We tested how well the tourniquets could hold pressure for up to 2 hours. RESULTS: A Kruskal-Wallis test revealed significant differences between the groups (p<.05). Post-hoc testing revealed a signif- icant difference between the C-A-T and the Ukrainian tourni- quet (p=.004). A similar significance was not found between the SOF™TT-W Wide and the Ukrainian model (p=.08). Dis- cussion: The Ukrainian model can hold pressure as well as the commercially available tourniquets. There is much value if this can be produced close to the battlefield. Factors including lo- gistics, cost, and self-sufficiency are important during wartime. CONCLUSION: We found that our sample of 3D-printed tourni- quets, currently used in the war in Ukraine, could maintain pressure as well as the commercially available tourniquets. In- deed, our tests demonstrated that it could maintain a signifi- cantly higher pressure.

Sports safety matting diminishes cardiopulmonary resuscitation quality and increases rescuer perceived exertion.

OBJECTIVES: Compliant surfaces beneath a casualty diminish the quality of cardiopulmonary resuscitation (CPR) in clinical environments. To examine this issue in a sporting environment, we assessed chest compression quality and rescuer exertion upon compliant sports safety matting. METHODS: Twenty-seven advanced life support providers volunteered (13 male/14 female; mass = 79.0 ± 12.5 kg; stature = 1.77 ± 0.09 m). Participants performed 5 × 2 min, randomized bouts of continuous chest compressions on a mannequin, upon five surfaces: solid floor; low-compliance matting; low-compliance matting with a backboard; high-compliance matting; high-compliance matting with a backboard. Measures included chest compression depth and rate, percentage of adequate compressions, and rescuer heart rate and perceived exertion. RESULTS: Chest compression depth and rate were significantly lower upon high-compliance matting relative to other surfaces (p<0.05). The percentage of adequate compressions (depth ≥50 mm) was lowest upon high-compliance matting (40 ± 39%) versus low-compliance matting (60 ± 36%) and low-compliance matting with a backboard (59 ± 39%). Perceived exertion was significantly greater upon high-compliance matting versus floor, low-compliance matting, and low-compliance matting with a backboard (p<0.05). CONCLUSION: Providers of CPR should be alerted to the detrimental effects of compliant safety matting in a sporting environment and prepare to alter the targeted compression depth and rescuer rotation intervals accordingly.

Cardiorespiratory demands of competitive rock climbing.

Rock climbing has become a mainstream sport, contested on the Olympic stage. The work/rest pattern of bouldering is unique among disciplines, and little is known about its physiological demands. This study characterised the cardiorespiratory responses to simulated competition. Eleven elite boulderers (7 male) volunteered to participate (age = 23.3 ± 4.5 years; mass = 68.2 ± 9.7 kg; stature = 1.73 ± 0.06 m; body fat = 10.4% ± 5%). Subjects completed incremental treadmill running to determine maximal capacities. On a separate day, they undertook a simulated Olympic-style climbing competition comprising 5 boulder problems, each separated by 5 min of rest. Pulmonary ventilation, gas exchange, and heart rate were assessed throughout. Total climbing time was 18.9 ± 2.7 min. Bouldering elicited a peak oxygen uptake of 35.8 ± 7.3 mL·kg-1·min-1 (∼75% of treadmill maximum) and a peak heart rate of 162 ± 14 beats·min-1 (∼88% of maximum). Subjects spent 22.9% ± 8.6% of climbing time above the gas exchange threshold. At exercise cessation, there was an abrupt and significant increase in tidal volume (1.4 ± 0.4 vs. 1.8 ± 0.4 L; p = 0.006, d = 0.83) despite unchanged minute ventilation. Cardiorespiratory parameters returned to baseline within 4 min of the rest period. In conclusion, competitive bouldering elicits substantial cardiorespiratory demand and evidence of tidal volume constraint. Further studies are warranted to explore the effect of cardiorespiratory training on climbing performance. Novelty: Competitive bouldering evokes a high fraction of maximal oxygen uptake and prolonged periods above the gas exchange threshold. Climbing appears to impose a constraint on tidal volume expansion. Cardiorespiratory indices in elite climbers return to baseline within 2-4 min.

The exercise pressor response to indoor rock climbing.

This paper assessed the blood pressure, heart rate, and mouth-pressure responses to indoor rock climbing (bouldering) and associated training exercises. Six well-trained male rock climbers (mean ± SD age, 27.7 ± 4.7 yr; stature, 177.7 ± 7.3 cm; mass, 69.8 ± 12.1 kg) completed two boulder problems (6b and 7a+ on the Fontainebleau Scale) and three typical training exercises [maximum voluntary contraction (MVC) isometric pull-up, 80% MVC pull-ups to fatigue, and campus board to fatigue]. Blood pressure and heart rate were measured via an indwelling femoral arterial catheter, and mouth pressure via a mouthpiece manometer. Bouldering evoked a peak systolic pressure of 200 ± 17 mmHg (44 ± 21% increase from baseline), diastolic pressure of 142 ± 26 mmHg (70 ± 32% increase), mean arterial pressure of 163 ± 18 mmHg (56 ± 25% increase), and heart rate of 176 ± 22 beats/min (76 ± 35% increase). The highest systolic pressure was observed during the campus board exercise (218 ± 33 mmHg), although individual values as high as 273/189 mmHg were recorded. Peak mouth pressure during climbing was 31 ± 46 mmHg, and this increased independently of climb difficulty. We concluded that indoor rock climbing and associated exercises evoke a substantial pressor response resulting in high blood pressures that may exceed those observed during other upper-limb resistance exercises. These findings may inform risk stratification for climbers.NEW & NOTEWORTHY This case study provides original data on the exercise pressor response to indoor rock climbing and associated training exercises through the use of an indwelling femoral arterial catheter. Our subjects exhibited systolic/diastolic blood pressures that exceeded values often reported during upper-limb resistance exercise. Our data extend the understanding of the cardiovascular stress associated with indoor rock climbing.

MEDEX2015: Greater Sea-Level Fitness Is Associated with Lower Sense of Effort During Himalayan Trekking Without Worse Acute Mountain Sickness.

Rossetti, Gabriella M.K., Jamie H. Macdonald, Matthew Smith, Anna R. Jackson, Nigel Callender, Hannah K. Newcombe, Heather M. Storey, Sebastian Willis, Jojanneke van den Beukel, Jonathan Woodward, James Pollard, Benjamin Wood, Victoria Newton, Jana Virian, Owen Haswell, and Samuel J. Oliver. MEDEX2015: Greater sea-level fitness is associated with lower sense of effort during Himalayan trekking without worse acute mountain sickness. High Alt Med Biol. 18:152-162, 2017.-This study examined the complex relationships of fitness and hypoxic sensitivity with submaximal exercise responses and acute mountain sickness (AMS) at altitude. Determining these relationships is necessary before fitness or hypoxic sensitivity tests can be recommended to appraise individuals' readiness for altitude. Forty-four trekkers (26 men; 18 women; 20-67 years) completed a loaded walking test and a fitness questionnaire in normoxia to measure and estimate sea-level maximal aerobic capacity (maximum oxygen consumption [[Formula: see text]O2max]), respectively. Participants also completed a hypoxic exercise test to determine hypoxic sensitivity (cardiac, ventilatory, and arterial oxygen saturation responses to acute hypoxia, fraction of inspired oxygen [Fio2] = 0.112). One month later, all participants completed a 3-week trek to 5085 m with the same ascent profile. On ascent to 5085 m, ratings of perceived exertion (RPEascent), fatigue by Brunel Mood Scale, and AMS were recorded daily. At 5085 m, RPE during a fixed workload step test (RPEfixed) and step rate during perceptually regulated exercise (STEPRPE35) were recorded. Greater sea-level [Formula: see text]O2max was associated with, and predicted, lower sense of effort (RPEascent; r = -0.43; p < 0.001; RPEfixed; r = -0.69; p < 0.001) and higher step rate (STEPRPE35; r = 0.62; p < 0.01), but not worse AMS (r = 0.13; p = 0.4) or arterial oxygen desaturation (r = 0.07; p = 0.7). Lower RPEascent was also associated with better mood, including less fatigue (r = 0.57; p < 0.001). Hypoxic sensitivity was not associated with, and did not add to the prediction of submaximal exercise responses or AMS. In conclusion, participants with greater sea-level fitness reported less effort during simulated and actual trekking activities, had better mood (less fatigue), and chose a higher step rate during perceptually regulated exercise, but did not suffer from worse AMS or arterial oxygen desaturation. Simple sea-level fitness tests may be used to aid preparation for high-altitude travel.

Comment on: Forearm oxygenation and blood flow kinetics during a sustained contraction in multiple ability groups of rock climbers.

We read with interest the authors' paper on this important area of climbing physiology. We however wish to highlight the incorrect identification of flexor carpi radialis (FCR) as a finger flexor and the implications it has for the conclusions described. FCR is a wrist flexor and has no direct bearing on flexion of the fingers during a climbing grip and thus could be expected to have a reduced oxygenation response compared to flexor digitorum profundus. We also would like to seek clarification from the authors regarding their confidence in their method for locating the two muscles under investigation as we feel this may not be accurately possible using the method described.

Physiological demands of mountain rescue work.

OBJECTIVE: To characterise the physical fitness of mountain rescue (MR) volunteers and the physical demands of a typical MR callout. METHODS: Eight MR volunteers (age ± SD: 45.5 ± 8.9 years) completed a laboratory-based treadmill exercise test to exhaustion. One week later subjects completed a field-based simulated callout to retrieve a casualty by stretcher. In both studies exercise intensity was evaluated by determination of oxygen uptake and other cardiovascular measures. RESULTS: The maximal oxygen uptake of the participants was 53 ml/kg/min (95% CI 45 to 60). In an unassisted callout, a typical rucksack load was 17% of body mass. Ascent time was 56 min (95% CI 40 to 72), of which 82% (95% CI 66% to 98%) was completed at hard or very hard intensity (above the respiratory compensation point). Descent time with a stretcher was 58 min (95% CI 52 to 64), of which only 6% (95% CI -4% to 16%) was completed at hard or very hard intensity. Correlations between heart rate and oxygen uptake were similar (p=0.254 by analysis of variance) during laboratory (r=0.72) and field testing, especially for the ascent (r=0.75). CONCLUSIONS: Mountain rescuers generally have high levels of physical fitness and are required to perform at very hard intensity for the majority of the ascent to a casualty. Heart rate is a simple yet valid measure of exercise intensity in MR personnel. These findings highlight important information on the unique physical demands faced by MR volunteers and provide direction for future research, volunteer selection and training.

Athletic profile of highly accomplished boulderers.

OBJECTIVE: Bouldering is a discipline of rock climbing completed at low height. Despite its popularity, scientific description of this sport remains sparse. This study aims to characterize the athletic profile of highly accomplished boulderers. METHODS: Twelve male highly accomplished boulderers (age 25.3 ± 4.9) were matched for age (± 5 yr), height (± 5 cm), and body mass (± 5 kg) to 12 nonclimbing aerobically trained controls. Body composition was determined by dual energy x-ray absorptiometry. Handgrip and climbing specific finger strength were assessed by dynamometry. Shoulder girdle and abdominal muscle endurance were assessed by isometric tests. Data were mostly analyzed by t-tests with an adjusted alpha level for multiple comparisons. Ethical approval was received from the School of Sport, Health and Exercise Sciences, Bangor University, Bangor, UK. RESULTS: Body composition was similar between the groups, apart from increased bone mineral density in climbers' forearms (1.1 ± 0.1 vs. 1.0 ± 0.1 g·cm(2), t((22))=2.798, p=0.010). Hand grip strength and climbing specific finger strength were greater in climbers (eg, finger strength: 494 ± 64 vs. 383 ± 79 N, t((22))=3.740, p=0.001), but handgrip and abdominal endurance were similar between the groups. In contrast, endurance of the shoulder girdle was substantially greater in boulderers (58 ± 13 vs. 39 ± 9 s, t((22))=4.044, p=0.001). CONCLUSION: Highly accomplished boulderers were characterized by handgrip and finger strength better than that of nonclimbing controls and superior to that of previously investigated elite climbers. In contrast, boulderers' body composition and core endurance were similar to that of controls (who were aerobically trained). These characteristics provide an athletic profile of highly accomplished boulderers, and hence identify possible targets that with further investigation may aid athlete selection and training program design.