Fatigue Recovery Research Articles

Effects of photobiomodulation therapy on the functional performance of healthy individuals: a systematic review with meta-analysis.

The aim of this study is to assess the effect of photobiomodulation therapy (PBMT) on functional performance concerning strength, fatigue, and functional capacity in healthy individuals. This systematic review with meta-analysis involved searches on data platforms and active searches of randomized clinical trials, focusing on PBMT as the sole intervention. Primary outcomes assessed included strength, fatigue, and functional capacity. Three reviewers screened studies by title and abstract using Rayyan, and data were extracted using a specific form. Bias risk was assessed using RoB2, and confidence in the evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). The RevMan was used for meta-analysis. Sixteen studies were included, totaling 340 individuals (183 males and 157 women). Most articles presented a low risk of bias. Variability was observed in device types and application domains, including wavelengths (655-905nm), power (10-200 nW), energy (0.6-30J per point), and time (30-100s per point). PBMT improved fatigue recovery (mean difference: 5.87; 95% CI 3.83, 7.91). There was no enhancement in strength (peak torque: mean difference 12.40; 95% CI -5.55, 30.55; one-repetition maximum test: mean difference 39.97, 95% CI -2.44, 82.38; isometric and isokinetic strength: mean difference 2.77, 95% CI -14.90, 20.44) nor improvement in short-term (mean difference 0.67, 95% CI -0.58, 1.91) and long-term (mean difference 18.44, 95% CI -55.65, 92.54) functional capacity. PBMT may aid in favoring fatigue recovery in healthy individuals; however, there's no evidence to support PBMT enhancing strength or improving functional capacity.

Effectiveness of Circulo Massage on Fatigue Recovery and Sleep Quality of Field Workers

The aim of the research was to determine the effectiveness of Circulo Massage for fatigue recovery and improving sleep quality. This study is quasi-experimental research with a one-group pretest-posttest design. The research included 30 field workers complaining of fatigue symptoms and decreased sleep quality. The treatment lasted 90 minutes and was administered once. Measurements were taken before and 24 hours after the treatment using the modified Fatigue Assessment Scale (FAS) to assess the fatigue scale, and the modified Pittsburgh Sleep Quality Index (PSQI) to measure the sleep quality index. Data analysis involved the paired t-test and Wilcoxon test. The results indicated that Circulo Massage effectively reduced the fatigue scale (p-value: 0.000) and significantly increased the sleep quality index of field workers (p-value: 0.000). In conclusion, Circulo Massage was found to be effective in reducing the fatigue scale and improving the sleep quality index. This research suggests that Circulo Massage can be beneficial for field workers experiencing fatigue and decreased sleep quality.

Disclosing the fatigue deformation mechanisms of different types of poly (ethylene terephthalate) industrial fibers on the base of the multiscale structural evolutions

AbstractThe fatigue behavior of poly (ethylene terephthalate) industrial fibers is a key issue in their long‐term service for engineering applications. To have a comprehensive understanding of the fatigue behavior, the high‐tenacity (HT) and low‐shrinkage (LS) PET fibers were selected to analyze the room temperature dynamic fatigue properties with different stress. Various techniques such as WAXD/SAXS and FTIR were employed to study the multiscale structure changes to disclose the fatigue mechanisms. Although the crystalline structure including orientation and crystallinity did not change, the amorphous structures varied with fatigue stress. The HT fiber exhibited a higher fatigue recovery ratio. The slight increase in amorphous orientation, and amorphous thickness was attributed to the oriented coiled molecular chains during tensile fatigue stress. In contrast, the LS fiber experienced plastic fatigue deformation with a lower recovery ratio. The molecular chains in the large amorphous domain are easily extended and oriented under tensile loading, increasing amorphous orientation and lamellar thickness. The fatigue mechanism for the LS fiber involved the conformation transition from gauche to trans conformers and a higher proportion of irreversible amorphous regions were formed. It is indicated that developing industrial filaments with small amorphous orientation and content is crucial to improving their fatigue resistance.

Factors Related to Suicidal Ideation in Adolescents According to Types of Stress.

We aimed to identify the factors associated with suicidal ideation by classifying adolescents into three groups: no stress, interpersonal stress, as well as academic and career stress. Using the data from the 16th Korea Youth Risk Behavior Web-Based Survey (2020), 15,343 adolescents were included in the study, and their socio-demographic characteristics as well as physical and psychological factors were assessed. A complex sample logistic regression was performed to identify factors associated with suicide. The following factors were significantly associated with suicide: fatigue recovery by sleep, body mass index, physical activity, and depression in the no stress group; current school, academic grade, drinking, depression, loneliness, and anxiety in the interpersonal stress group; and gender, current school, academic grade, father's educational level, drinking, fatigue recovery by sleep, depression, loneliness, subjective health, smartphone overdependence, as well as anxiety in the academic and career stress group (P < 0.05). To prevent suicide among adolescents, it is necessary to consider these factors when developing educational policies.

Effect of Jujubae Fructus on Fatigue Recovery in Mouse Exercise Model

OBJECTIVES Jujubae fructus (JF, &lt;i&gt;Ziziphus jujuba&lt;/i&gt; var. inermis Rehder) is an economically and agriculturally significant perennial fruit tree crop of the Rhamnaceae family and is used as a traditional herbal medicine. However, the anti-fatigue effect of JF has not been reported yet. The purpose of this study was to examine the anti-fatigue effect of JF by in vivo experiments.Methods Male ICR mice were classified into a saline-treated swimming load test group (control) and JF (1, 10, 100 mg/kg) supplied swimming load test group (JF), and randomly assigned to 5 mice per group. Distilled water and JF were orally administered. The anti-fatigue effect of JF was evaluated by open field test (OFT) and forced swimming test (FST).Results JF significantly increased the total distance moved in OFT in a dose-dependent manner. JF was significantly decreased immobility time compared to control group in the FST. The increase in lactic acid and lactate dehydrogenase after FST was suppressed by JF treatment. Consumption and recovery of energy sources (free fatty acid and triglyceride) were improved after FST through JF treatment. Administration of JF decreased the expression of neurotransmitters such as norepinephrine (NE), serotonin (5-HT), 5-hydroxyindole-acetic acid (5-HIAA), dopamine (DA) by FST in brain stem and hypothalamus.Conclusions Based on these results, this study provides scientific proof for anti-fatigue effect of JF and it could be a useful material.

Trunk variability and local dynamic stability during gait after generalized fatigue induced by incremental exercise test in young women in different phases of the menstrual cycle.

The purpose of this study was to identify how generalized fatigue along with hormonal changes throughout the menstrual cycle affects trunk variability and local dynamic stability during gait. General fatigue was induced by an incremental test on a treadmill, and the menstrual cycle was divided into three phases: follicular, ovulatory, and luteal. Twenty-six healthy, young volunteers (aged 18 to 28 years) who did not use oral contraceptives or other hormonal drugs with a regular menstrual cycle participated in the study. They walked on the treadmill for 4 min at the preferred speed, before the incremental test, followed by four sets of 4 min alternating between walking, also at preferred speed, and resting. From trunk kinematic data, the following were extracted: the mean of the standard deviation along strides, as a measure of variability, and the maximum Lyapunov exponent, as a measure of local dynamic stability (LDS). After the incremental test, variability increased, and LDS decreased. However, they showed a tendency to return to the initial value faster in women compared to previous results for men. In the follicular phase, which has less hormonal release, the volunteers had an almost complete recovery in LDS soon after the first rest interval, suggesting that female hormones can interfere with fatigue recovery. Nevertheless, concerning the LDS, it was significantly lower in the luteal phase than in the follicular phase. Women that are not taking oral contraceptives should be aware that they are susceptible to increased gait instabilities in the pre-menstrual phase after strenuous activities.

Short-term neuronal and synaptic plasticity act in synergy for deviance detection in spiking networks.

Sensory areas of cortex respond more strongly to infrequent stimuli when these violate previously established regularities, a phenomenon known as deviance detection (DD). Previous modeling work has mainly attempted to explain DD on the basis of synaptic plasticity. However, a large fraction of cortical neurons also exhibit firing rate adaptation, an underexplored potential mechanism. Here, we investigate DD in a spiking neuronal network model with two types of short-term plasticity, fast synaptic short-term depression (STD) and slower threshold adaptation (TA). We probe the model with an oddball stimulation paradigm and assess DD by evaluating the network responses. We find that TA is sufficient to elicit DD. It achieves this by habituating neurons near the stimulation site that respond earliest to the frequently presented standard stimulus (local fatigue), which diminishes the response and promotes the recovery (global fatigue) of the wider network. Further, we find a synergy effect between STD and TA, where they interact with each other to achieve greater DD than the sum of their individual effects. We show that this synergy is caused by the local fatigue added by STD, which inhibits the global response to the frequently presented stimulus, allowing greater recovery of TA-mediated global fatigue and making the network more responsive to the deviant stimulus. Finally, we show that the magnitude of DD strongly depends on the timescale of stimulation. We conclude that highly predictable information can be encoded in strong local fatigue, which allows greater global recovery and subsequent heightened sensitivity for DD.

The impact of a 40-min nap on neuromuscular fatigue profile and recovery following the 5-m shuttle run test.

This study aims to investigate the impact of a 40-min nap opportunity on perceived recovery, exertion, and maximal voluntary isometric contraction (MVIC) following the 5-m shuttle run test (5SRT), after 1 night of normal sleep. In a randomised, counterbalanced, cross-over design, 17 trained men (mean [SD] age 20 [3] years, height 173 [6] cm, body mass 68 [6] kg) performed a 5SRT under two conditions: a 40-min nap opportunity and no-nap condition. After both conditions, electromyography signals during a 5-s isometric knee extension were recorded before and immediately after the 5SRT. Two electrical nerve stimulations at the femoral nerve were measured during and after the MVIC. Force, voluntary activation level, M-wave amplitudes, potentiated twitch, and electromyography signals (root mean square) were measured during each MVIC. Perceived exertion was recorded after each repetition of the test and perceived recovery was determined after the end of the MVIC. Compared to the no-nap condition, the 40-min nap resulted in significant enhancements in both the highest distance (p < 0.01, Δ = +7.6%) and total distance (p < 0.01, Δ = +7.5%). Before and after exercise, values for MVIC, root mean square, M-wave amplitudes, and voluntary activation level were improved after the 40-min nap opportunity compared to no-nap condition (all p ≤ 0.01). Values for perceived exertion and recovery were improved after the 40-min nap opportunity in comparison with no-nap condition (p ≤ 0.01). A 40-min nap opportunity improved repeated high-intensity short-term maximal performance, perceived recovery, associated neuromuscular responses, and reduced perceived fatigue. Therefore, our findings suggest that central and peripheral processes are involved in the improvements of 5SRT performance after napping.

The Effect of 6-Meter Underwater Diving Intervention on Recovery of Exercise-Induced Fatigue

Objective: To evaluate the effect of 6-meter underwater diving on recovery of exercise-induced fatigue and explore the potential mechanism. Method: Thirty-three male sophomores majored in physical education were included in this self-control, cross-over study. The fatigue was induced through programed swimming exercise at same intensity for both control and intervention groups. After exercise-induced fatigue, the subjects recovered through sitting on the floor and 6-meter underwater diving for 15 minutes in control and intervention groups respectively. The parameters observed included Heart Rate (HR), Critical Flicker Frequency (CFF), Simple Reaction Time (SRT) and Standing Long Jump (SLJ). Results: The HR was faster after exercise and recovery compared to that before exercise in both groups. SLJ was shorter after recovery compared to before exercise fatigue in both groups. After diving recovery, the CFF was lower than that before exercise fatigue, while the index of SRT was higher than that before exercise fatigue. Compared with the control group, the HR and SRT were significantly lower, but the SLJ and CFF were significantly higher in the intervention group than those of control group (HR, p&lt;0.05; SRT, p&lt;0.01, SLJ, CFF p&lt;0.01). Conclusion: The fatigue recovery effect of 6m underwater environment is better than that of land recovery. The low temperature, mild hyperbaric oxygen, water pressure and buoyancy in under water environment may promote the repair of muscle and motor nerve after exercise and improve the exercise performance after intervention.

The effects of hand dominance, fatigue, and sex on muscle activation during a repetitive overhead fatiguing task

Previous studies have shown that the dominant arm is generally stronger and more resistant to fatigue. However, whether there are side differences in shoulder muscle activation during a fatiguing upper limb task, and whether this varies according to sex, is unknown. Thirty right-handed adults (15 females) were recruited to complete two sessions of an overhead repetitive fatiguing task (shoulder flexion between 90 and 135° at 1 Hz), performed in two separate sessions with their dominant arm (DA) and non-dominant arm (NDA) until exhaustion. Electromyographic (EMG) data was collected from 11 shoulder muscles of the moving arm, and their activation amplitude (RMS) and activation variability (SD) were assessed. Results show that time to exhaustion was not affected by arm or by sex. There were some main arm effects on EMG activity amplitude, with higher activity on the DA's pectoralis major (p < 0.001), and on the NDA's middle (p = 0.009) and posterior deltoid (p = 0.001) and infraspinatus (p < 0.001). The pectoralis major was affected by arm and fatigue mostly in males. Their DA's pectoralis major activity amplitude was higher, and the amplitude variability was lower, compared to the NDA, with both parameters showing fatigue-dependent decreases at the NDA only (arm x sex x fatigue: RMS: p = 0.007; SD: p = 0.001). As for females, the DA variability of their lower trapezius was smaller, and that of their subscapularis was higher, compared to the NDA (sex x arm, p = 0.028, p = 0.05). There was also more EMG variability on the supraspinatus' dominant side, and on the posterior deltoid and infraspinatus ND side. Results show an overhead shoulder flexion task dependency on pectoralis major control in males, and on lower trapezius and shoulder girdle stabilizers in females, which could be related to both sex- and gender-based factors. This knowledge can help identify side-specific injury risk factors due to overhead work in males and females, and help determine the appropriateness of implementing sex-specific workplace protocols, including alternating arms as fatigue compensatory and recovery strategies.

Global practitioner assessment and management of mental fatigue and mental recovery in high-performance sport: Aneed for evidence-based best-practice guidelines.

Mental fatigue and mental recovery have gained scientific attention in relation to sporting performance, yet best practice assessment and management methods are lacking. A greater understanding of current knowledge and practices in high-performance sport are necessary. To understand the contemporary knowledge, beliefs, monitoring processes, management strategies, perceived responsibility, sources of evidence, and challenges, when assessing the mental fatigue and mental recovery of athletes in high-performance sport. A mixed-methods survey approach obtained information from 156 multi-disciplinary high-performance sport practitioners. Descriptive outputs were reported and potential differences between key concepts were detected using Wilcoxon-signed rank analysis. Thematic analysis interpreted open-text responses. Only 11.5% and 5.1% of respondents indicated they were "very" knowledgeable about mental fatigue and mental recovery, respectively. Knowledge (p < 0.001) and confidence in application (p = 0.001) were significantly greater for mental fatigue than mental recovery. Nearly all respondents perceived mental fatigue and mental recovery impacted training and competition performance, with a greater negative impact during competition (p < 0.001). A limited number of respondents reported deliberate assessment (31.1%) or management (51.2%) of mental fatigue and mental recovery. A combination of sources of evidence were used to inform practice, with common challenges to implementation including staff knowledge, athlete-buy in, time-availability, and a lack of evidence. Practitioners reported that assessing and managing mental fatigue and mental recovery was multi-disciplinary in nature. Practitioners reported that mental fatigue and mental recovery did impact performance, yet this was not reflected in the implementation of evidence-based assessment and management practices in high-performance sport.

Considerations for occupational heat exposure: A scoping review

The ability to regulate core body temperature is a critical factor in avoiding occupational heart stress in demanding environments. Heat-related illness in an occupational setting is complex and multifactorial and includes environment (intrinsic and extrinsic), the occupational clothing requirements and physiological factors. Much of this research began in the gold mines in South Africa after several miners died due to heat related illness. Similar research was conducted during World War Two and was crucial for the creation of acclimatization techniques and strategies for acquiring thermal tolerance. Techniques such as fatigue recovery and body cooling are still used today to prevent heat related illness in individuals with occupations that have frequent exposure to heat and high physical loads. These individuals are at greater risk of heat related illness as extended exposure to a hot or humid environment in combination with strenuous physical activity can overwhelm the body’s homeostatic cooling mechanisms. In addition, individuals from special populations with chronic or acute health impacts such as diabetes mellitus, also have a greater risk for the aforementioned. Currently, there are several heat prevention strategies, including training and education, regulation and monitoring, in place to protect workers from heat related illness and casualty. These strategies, along with future considerations and the impact of climate change will be highlighted in this review.

Insights on the Hair Keratin Structure Under Different Drying Conditions

ABSTRACT It is important to understand the patterns of hair keratin integrity caused by drying methods. No previous information exists in the literature to compare different drying conditions needed to assess physical changes in the hair keratin. We used human hair for these experiments. We found that different drying conditions greatly influence the wearing fatigue of the hair fibers. Using a microfiber towel (80% polyester/20% nylon) to remove the excess water seems to better retain the integrity of human hair when compared to drying with a blow-drier or a cotton towel. Hair dried with a microfiber towel showed strong intensity bands at 1664 cm-1 consistent with an alpha-helix structure, while these bands were absent in the spectrum of the hair dried with a blow-drier or a cotton towel. Fatigue recovery of the hair sample dried with a microfiber towel showed much higher wear resistance when compared with the cotton towel and blow-drier processes. These findings were supported by FTIR (Fourier transform infrared) which aided in the elucidation of the secondary structure of alpha-keratin and its effect in the stabilization of hair fibers. When hair samples were exposed to high temperatures, DSC (Differential Scanning Calorimetry) profiles provided information about the movement of water molecules from the fiber, being the enthalpy for hair dried with microfiber towel the highest value. Contributions from damage, friction, and heat were correlated with the molecular structure, in particular, the alpha-helixes predicting that drying condition using a microfiber towel is the process that better preserves hair integrity.

Effect Of Protein Sports Drink Supplementation On Fatigue Recovery After Acute Exhaustive Exercise In Table Tennis Players

Effect Of Protein Sports Drink Supplementation On Fatigue Recovery After Acute Exhaustive Exercise In Table Tennis Players

Acute outcomes of acupuncture and dry needling over peripheral acute fatigue in untrained healthy volunteers: A randomized controlled clinical trial

Peripheral acute fatigue (PAF) is defined as when the skeletal muscle is incapable of generating power. We aimed to investigate the acute effects of traditional Chinese acupuncture (TCA) and dry needling (DN) over PAF induced on the biceps brachii of untrained healthy volunteers. We conducted a randomized, single-blind controlled clinical trial. All volunteers (n = 45) underwent fatigue induction protocols repeated before and after treatment with TCA (TCA group; TCAg; n = 15), DN (DN group; DNg; n = 15), and rest (control group; Cg; n = 15). Assessments of PAF, skin temperature, and exercise time occur before and after each event: 1st fatigue induction (FI), treatment, and 2nd FI. We used repeated measures ANOVA adjusted with Bonferroni post hoc test to determine any change in tested variables (PAF-VAS, PAF-EMG, and skin temperature) at different time points compared to the baseline. Paired Samples t-test was used for the variable exercise times. All statistical tests considered’ the significance level at p ≤ 0,05. There was no difference between groups in acute fatigue recovery (p = 0.19). All intragroup analyses were significant (p ≤ 0.05) and all volunteers show a reduction in fatigue perception after treatment (p ≤ 0,05), however, exercise time did not ameliorate after TCA or DN (p > 0.77). A single session of TCA and, DN can equally reduce fatigue, temperature, and exercise time over PAF induced on biceps brachii of untrained healthy volunteers.

The effectiveness of application of ice massage to accelerate fatigue recovery in football athletes

Introduction. Injuries in soccer players frequently range from minor ones like abrasions, hematomas, grade one strains and sprains, and muscle cramps, where players can continue to play, to severe injuries such as torn ligaments, dislocations, and fractures that prevent players from continuing the game. Based on field observations, some trainers apply ice massage treatments to injured athletes. Aim. This study aimed to determine the effect of ice massage on accelerating muscle fatigue recovery in soccer athletes, specifically in relation to blood lactate levels. Method. The research methodology employed in this study is a True Experiment. Result. Findings indicate that ice massage therapy provided to injured soccer athletes can expedite the healing process and alleviate pain. Conclusion. Based on data processing and analysis, it's concluded that ice massage significantly accelerates recovery from muscle fatigue in soccer athletes when considering lactate levels and the results from the Visual Analog Scale (VAS) test.

Chronic fatigue and recovery among nurses working two-shift and three-shift rotations

BackgroundShift patterns influence nurses’ work and rest conditions. Limited information is available about the nurses' recovery, fatigue, and their associated factors considering shift patterns. AimThis study explored the association between fatigue and recovery and factors associated with recovery and chronic fatigue among nurses working a three-shift (8 hour shifts) or two-shift (more than 12 hour shifts) rotations in Japan. MethodsThis cross-sectional secondary analysis included 807 nurses from a previous questionnaire survey. Fatigue (acute and chronic) and intershift recovery were measured using the Occupational Fatigue Exhaustion Recovery Scale. FindingsIntershift recovery was significantly lower among nurses working a three-shift rotations compared to nurses working a two-shift rotations. Nurses aged ≥40 years tended to experience severe chronic fatigue working in the two-shift rotations. In both shift patterns, overtime hours and low sleep quality were associated with lower intershift recovery and higher chronic fatigue. In the three-shift rotations, having children and being activity-oriented in leisure time were associated with higher intershift recovery and lower chronic fatigue. In the two-shift rotations, activity orientation was significantly associated with lower chronic fatigue. DiscussionsThe three-shift rotations influenced nurses’ intershift recovery more than the two-shift rotations. Regardless of shift patterns, managers must restrict overtime and encourage nurses to maintain sleep quality, family roles, and leisure activities. Moreover, considering nurses’ age while selecting and organising shift patterns may prevent chronic fatigue. ConclusionFatigue management based on the characteristics and associated factors of fatigue and recovery for each shift pattern revealed in this study prevents chronic fatigue, which may contribute to the retention of nurses.

Validated Wearable Device Shows Acute Postoperative Changes in Sleep Patterns Consistent With Patient-Reported Outcomes and Progressive Decreases in Device Compliance After Shoulder Surgery

To assess the utility of a validated wearable device (VWD) in examining preoperative and postoperative sleep patterns and how these data compare to patient-reported outcomes (PROs) after rotator cuff repair (RCR) or total shoulder arthroplasty (TSA). Male and female adult patients undergoing either RCR or TSA were followed up from 34 days preoperatively to 6 weeks postoperatively. Sleep metrics were collected using a VWD in an unsupervised setting. PROs were assessed using the following validated outcome measures: Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function questionnaire; American Shoulder and Elbow Surgeons self-evaluation questionnaire; visual analog scale assessing pain; and Disabilities of the Arm, Shoulder and Hand questionnaire. Data were analyzed preoperatively and at 2-week intervals postoperatively with χ2 analysis to evaluate device compliance. Sleep metrics and PROs were evaluated at each interval relative to preoperative values within each surgery type with an analysis of variance repeated on time point. The relation between sleep metrics and PROs was assessed with correlation analysis. A total of 57 patients were included, 37 in the RCR group and 20 in the TSA group. The rate of device compliance in the RCR group decreased from 84% at surgery to 46% by 6 weeks postoperatively (P < .001). Similarly, the rate of device compliance in the TSA group decreased from 81% to 52% (P < .001). Deep sleep decreased in RCR patients at 2 to 4 weeks (decrease by 10.99 ± 3.96 minutes, P= .021) and 4 to 6 weeks postoperatively (decrease by 13.37 ± 4.08 minutes, P= .008). TSA patients showed decreased deep sleep at 0 to 2 weeks postoperatively (decrease by 12.91 ± 5.62 minutes, P= .045) and increased rapid eye movement sleep at 2 to 4 weeks postoperatively (increase by 26.91 ± 10.70 minutes, P= .031). Rapid eye movement sleep in the RCR group and total sleep in the TSA group were positively correlated with more favorable PROs (P < .05). VWDs allow for monitoring components of sleep that offer insight into potential targets for improving postoperative fatigue, pain, and overall recovery after shoulder surgery. However, population demographic factors and ease of device use are barriers to optimized patient compliance during data collection. Level IV, diagnostic case series.

Does High Medial Elbow Stress During Pitching Compromise the Dynamic Stabilizers of The Elbow?

The flexor carpi ulnaris (FCU) and flexor digitorum superficialis (FDS) are thought to provide dynamic stability to the medial elbow, with a lesser contribution from the pronator teres (PT). The purpose of this study was to determine if baseball pitchers with higher valgus elbow torque experience greater FCU and FDS strength loss. Controlled Laboratory Study. A pilot study was performed to determine if middle and ring finger flexion strength tests preferentially activated the FCU and FDS versus the PT (10 men age 36±12 yr). EMG amplitudes, expressed as percent of maximal voluntary contraction (MVC) were compared between tests and muscles. In a field study of college baseball pitchers, middle finger, ring finger and grip strength were tested prior to, immediately after, and one day after 14 pitching performances in 10 pitchers (21±2 yr). Elbow valgus torque was measured from an inertial measurement unit, housed in a compression sleeve and pitchers were categorized as having high or low valgus torque. For the pilot study EMG activations were 74% FDS, 66% FCU and 35% PT for the middle finger test (muscle effect p=0.032) and 93% FCU, 61% FDS and 23% PT for the ring finger test (muscle effect p=0.005). In the field study, pitchers with high valgus torque showed marked post-game middle finger fatigue (88% of baseline) and incomplete recovery the following day (95%), while pitchers with low valgus torque showed no strength loss (107% post game, 106% a day later; group x time p=0.022). Results were similar for ring finger strength (high torque: 94% post game 96% a day later; low torque: 114% post game 107% a day later; group x time p=0.048). By contrast, grip strength was not different between pitchers with high versus low valgus torque (p=0.143). High medial elbow stress during pitching fatigues the dynamic stabilizers of the medial elbow. Level 3©The Author(s).

Altitude trekking and Robuvit®: fatigue prevention and recovery.

Altitude trekking and Robuvit®: fatigue prevention and recovery.