The effect of local skin cooling before a sustained, submaximal isometric contraction on fatigue and isometric quadriceps femoris performance: A randomized controlled trial

Ice Massage on the Calf Improves 4-km Running Time Trial Performance in a Normothermic Environment

Purpose: Local cooling with ice massage is a practical and inexpensive technique to decrease perceptual stress and improve motor performance in hot environments. However, it is unknown whether local cooling with ice massage reduces perceptual responses to exercise and improves performance in a normothermic environment. Thus, we investigated whether ice massage on the calf muscles before a 4 km running time trial (TT4km) reduced the ratings of perceived exertion (RPE) and perceived muscle pain, thereby improving exercise performance in a normothermic environment. Methods: After familiarizations, fourteen recreationally endurance-trained men (age = 21.3 ± 1.2 years; body weight = 67.5 ± 9.2 kg; height = 173.0 ± 5.0 cm) underwent two TT4km on a 400 m track in normothermic conditions with or without ice massage before the trial. The time of running, RPE, and pain perception were recorded every 400 m throughout the TT4km. Results: The local cooling with ice massage increased the mean speed (~ 5.2%, p = 0.03) and decreased the time to complete the TT4km (~ 5.5%, p = 0.03). Accordingly, ice massage also reduced the exercise-derived pain perception (p = 0.028), although no effect has been found in the RPE during the TT4km (p = 0.32). Conclusion: Together, these results showed that local cooling with ice massage before the exercise reduced the exercise-derived pain perception, enabling runners to increase the speed for a comparable RPE during exercise, thereby improving the TT4km performance in a normothermic environment.

Direct Effect of Local Cryotherapy on Muscle Stimulation, Pain and Strength in Male Office Workers with Lateral Epicondylitis, Non-Randomized Clinical Trial Study

Background: Local cryotherapy (LC) is one of the physiotherapeutic methods used in the conservative treatment of lateral epicondylitis (LE). The aim of the study was to verify the direct effect of a single LC procedure on the clinical symptoms of lateral epicondylitis enthesopathy (pain, pain free grip, PFG) and its effect on the bioelectrical properties of the wrist extensor muscles at rest, on maximal contraction and isometric contraction during fatigue. Methods: The study group was 28 men (35.4 ± 6.13 years) with confirmed unilateral epicondylitis. The performed procedures included the assessment of pain (visual analogue scale, VAS), PFG and ARMS (root-mean-square amplitude) and mean frequencies (MNF) of the sEMG signal before (T0) and after (T1) LC on the side with enthesopathy (ECRE) and without enthesopathy (ECRN/E). Results: There was an increase in the ARMS values of the signals recorded during rest and MVC from the ECR muscles both with and without enthesopathy (p = 0.0001, p = 0.006), an increased PFG after LC only on the side with LE (p < 0.0001) and decreased pain (p < 0.0001). During isometric fatigue contraction, a higher ARMS on both the ECRE side (p < 0.0001) and the ECRN/E side (p < 0.0001) was observed after LC treatment, and a lower MNF was observed on both the ECRN/E side (p < 0.0001) and the ECRE side (p < 0.0001) after LC. Conclusions: LC reduces the pain and increases PFG and muscle excitation expressed by ARMS and seems to delay muscle fatigue.

Comparison of the TOFscan and the TOF-Watch SX during pediatric neuromuscular function recovery: a prospective observational study

BACKGROUND

TOFscan is a three-dimensional acceleromyography neuromuscular monitoring device that does not require initial calibration before muscle relaxant injection. This study aimed to compare TOFscan with TOF-Watch SX, the currently widely accepted uni-dimensional acceleromyography, for use among the pediatric population. We aimed to assess the agreement between TOFscan with TOF-Watch SX in the pediatric population's neuromuscular recovery.

METHODS

A total of 35 children aged 6-12 years were enrolled. Prior to any muscle relaxant injection, TOFscan and TOF-Watch SX were applied at each opposite arm and monitoring began concurrently throughout neuromuscular recovery. Calibration was performed for TOF-Watch SX, and train-of-four values were recorded every 15 s. Agreement between the two devices was evaluated with Modified Bland-Altman analysis.

RESULTS

The bias between TOF-Watch SX and TOFscan were all within the 95% limits of agreement. The bias and standard deviation were smaller and the limit of agreement was narrower in the normalized group than in the non-normalized group [normalized bias -0.002 (95% CI, -0.013 to 0.010), standard deviation (SD) 0.111 vs non-normalized bias 0.010 (95% CI, -0.003 to 0.0236), SD 0.127].

CONCLUSIONS

TOFscan reliably demonstrated lack of bias and good concordance with TOF-Watch SX throughout the neuromuscular recovery, especially when normalized. Despite technical limitations, the two devices were unbiased along the path of spontaneous and pharmacological reversal in pediatric patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03775603. Registered on 13 March 2018.

Adult individuals with congenital, untreated, severe isolated growth hormone deficiency have satisfactory muscular function

PURPOSE

While growth hormone (GH) and the insulin-like growth factor type I (IGF-I) are known to exert synergistic actions on muscle anabolism, the consequences of prolonged GH deficiency (GHD) on muscle function have not been well defined. We have previously described a large cohort of subjects with isolated GHD (IGHD) caused by a mutation in the GH-releasing hormone receptor gene, with low serum levels of GH and IGF-I. The aim of this study was to assess muscular function in these IGHD subjects.

METHODS

A total of 31 GH-naïve IGHD (16 males) and 40 control (20 males) subjects, matched by age and degree of daily physical activity, were enrolled. Fat free mass was measured by bioelectrical impedance; muscle strength by dynamometry of handgrip, trunk extension, and knee extension; myoelectric activity and muscle fatigue by fractal dimension; conduction velocity in vastus medialis, rectus femoris, and vastus lateralis muscles by surface electromyography.

RESULTS

The IGHD group showed higher knee extension strength both when corrected for weight and fat free mass, and higher handgrip and trunk extension strength corrected by fat free mass. They also exhibit higher conduction velocity of the muscles vastus medialis, rectus femoris, and vastus lateralis, but lower free fat mass and myoelectric activity of the vastus medialis, rectus femoris and vastus lateralis. There were no differences between the two groups in fractal dimension in all studied muscles.

CONCLUSION

Individuals with untreated IGHD have better muscle strength parameters adjusted for weight and fat free mass than controls. They also exhibit greater peripheral resistance to fatigue, demonstrating satisfactory muscle function.