Our results support the use of a foam roller in combination with a static-stretching protocol. If time allows and maximal gains in hip-flexion ROM are desired, foam rolling the hamstrings muscle group before static stretching would be appropriate in noninjured subjects who have less than 90° of hamstring ROM.

Context: No evidence-based recommendation exists regarding how far clinicians should insert a rectal thermistor to obtain the most valid estimate of core temperature. Knowing the validity of temperatures at different rectal depths has implications for exertional heat-stroke (EHS) management.Objective: To determine whether rectal temperature (T rec ) taken at 4 cm, 10 cm, or 15 cm from the anal sphincter provides the most valid estimate of core temperature (as determined by esophageal temperature [T eso ]) during similar stressors an athlete with EHS may experience.Design: Cross-sectional study. Setting: Laboratory.Patients or Other Participants: Seventeen individuals (14 men, 3 women: age ¼ 23 6 2 years, mass ¼ 79.7 6 12.4 kg, height ¼ 177.8 6 9.8 cm, body fat ¼ 9.4% 6 4.1%, body surface area ¼ 1.97 6 0.19 m 2 ). Intervention(s): Rectal temperatures taken at 4 cm, 10 cm, and 15 cm from the anal sphincter were compared with T eso during a 10-minute rest period; exercise until the participant's T eso reached 39.58C; cold-water immersion (~108C) until all temperatures were 388C; and a 30-minute postimmersion recovery period. The T eso and T rec were compared every minute during rest and recovery. Because exercise and cooling times varied, we compared temperatures at 10% intervals of total exercise and cooling durations for these periods.Main Outcome Measure(s): The T eso and T rec were used to calculate bias (ie, the difference in temperatures between sites).Results: Rectal depth affected bias (F 2,24 ¼ 6.8, P ¼ .008). Bias at 4 cm (0.858C 6 0.788C) was higher than at 15 cm (0.658C 6 0.688C, P , .05) but not higher than at 10 cm (0.758C 6 0.768C, P . .05). Bias varied over time (F 2,34 ¼ 79.5, P , .001). Bias during rest (0.428C 6 0.278C), exercise (0.238C 6 0.538C), and recovery (0.658C 6 0.358C) was less than during cooling (1.728C 6 0.658C, P , .05). Bias during exercise was less than during postimmersion recovery (0.658C 6 0.358C, P , .05).Conclusions: When EHS is suspected, clinicians should insert the flexible rectal thermistor to 15 cm (6 in) because it is the most valid depth. The low level of bias during exercise suggests T rec is valid for diagnosing hyperthermia. Rectal temperature is a better indicator of pelvic organ temperature during cold-water immersion than is T eso .

Context: The National Athletic Trainers' Association and the American College of Sports Medicine have recommended removing American football uniforms from athletes with exertional heat stroke before cold-water immersion (CWI) based on the assumption that the uniform impedes rectal temperature (T rec ) cooling. Few experimental data exist to verify or disprove this assumption and the recommendations.Objectives: To compare CWI durations, T rec cooling rates, thermal sensation, intensity of environmental symptoms, and onset of shivering when hyperthermic participants wore football uniforms during CWI or removed the uniforms immediately before CWI.Design: Crossover study. Conclusions: Whereas participants cooled faster in NO pads , we still considered the PADS cooling rate to be acceptable (ie, .0.168C/min). Therefore, if clinicians experience difficulty removing PADS or CWI treatment is delayed, they may immerse fully equipped hyperthermic football players in CWI and maintain acceptable T rec cooling rates. Otherwise, PADS should be removed preimmersion to ensure faster body core temperature cooling.Key Words: clothing, equipment, exertional heat stroke, rectal temperature Key PointsBody core temperature decreased faster when participants wore undergarments, shorts, and crew socks than when they wore the full American football uniform (PADS) without shoes during cold-water immersion (CWI). If CWI is delayed or clinicians have difficulty removing PADS, they can immerse hyperthermic football players in PADS and maintain acceptable core temperature cooling rates. The PADS should be removed before CWI if that can be done properly, easily, and within 30 minutes of athlete collapse.A merican football players (AFPs) may be at higher risk of developing exertional heat stroke (EHS) in part because of the equipment-intensive uniform worn during the sport.1 These athletes compete and often practice while wearing a full uniform consisting of shoes; crew socks; undergarments; shorts; game pants; undershirt; shoulder pads; jersey; helmet; and padding over the thighs, knees, hips, and tailbone (PADS).2,3 The increased metabolic demand and physiologic strain of exercising while wearing PADS, combined with a decreased evaporative surface area to dissipate heat, can result in substantial heat storage 2-5 and may contribute to the development of exertional heat illness. In fact, the rate of exertional heat illness in secondary school AFPs is 11 times higher than that in all other sports combined. 6 If EHS develops and body core temperature stays above the critical threshold for cell damage (approximately 40.58C) longer than 30 minutes, the risk of morbidity and mortality increases. 7,8 Therefore, it is paramount to develop efficient protocols for treating AFPs with hyperthermia.The criterion standard treatment for EHS is cold-water immersion (CWI) because of its superior cooling rates (ie, .0.168C/min) 7,9 and high survival rates when implemented shortly after the onset of symptoms.

We speculate that higher skin temperatures before CWI, less shivering, and greater conductive cooling explained the faster cooling in full uniform. Cooling rates were considered ideal when the full uniform was worn during CWI, and wearing the full uniform did not cause a greater postimmersion hypothermic afterdrop. Clinicians may immerse football athletes with hyperthermia wearing a full uniform without concern for negatively affecting body-core cooling.

Acute VIMCs increase cramp susceptibility. Clinicians should apply treatments for at least 60 min postcramp to decrease the probability of cramp recurrence. Muscle Nerve 56: E95-E99, 2017.

The purpose of the present study was to examine the differences in upper body power output among lineman and nonlineman division I collegiate football players and to examine the influence of 2 normalization procedures: (a) simple ratio scaling and (b) standardized allometric scaling. Ten lineman (mean +/- SD: age = 19.3 +/- 1.6 years; height = 187.7 +/- 4.7 cm; mass = 127.7 +/- 13.3 kg) and 14 nonlineman (19.6 +/- 1.4 years; 181.8 +/- 5.2 cm; 92.3 +/- 10.6 kg) performed a multiple repetition bench press power test at 50% of their 1 repetition maximum. Peak power (PP) was determined from a Tendo weightlifting analyzer that was attached to the barbell. The PP values were then analyzed under 3 conditions that included: (a) no scaling (absolute values), (b) ratio scaling (PP body mass), and (c) allometric scaling (PP body mass). The results indicated that the larger lineman demonstrated greater absolute PP values (p = 0.02); however, ratio scaling favored the smaller nonlineman group (p = 0.04). There were no differences in PP values between positions after the standardized allometric scaling procedure (p = 0.60). These findings indicated that the standardized allometric scaling procedure may be a more effective method for normalizing PP values among elite division I collegiate football players.

Skinfold thickness at common cryotherapy treatment sites varied based on level of physical activity and sex. Therefore, clinicians should measure skinfold thickness to determine an appropriate cryotherapy duration.

Thermocouple models vary in reliability and validity. Scientists should test and report the uncertainty of their equipment rather than depending on manufactures' claims.