The impact of fatigue caused by sprint running on the median power frequency of the hamstring muscle group

Hamstring strain injuries (HSI) are the predominant non-contact injury in many sports. Intermittent running has been shown to result in preferential reductions in eccentric hamstring strength, which increase the risk of sustaining a HSI. The eccentric specific nature of this decline in hamstring function implicates central mechanisms, as peripheral fatigue mechanisms tend to impact upon both concentric and eccentric contractions modes. However, neural function of the hamstrings, such as the median power frequency (MPF) of the surface electromyography signal has yet to be examined in the fatigued hamstring following intermittent sprint running. AIM: To determine the impact of fatigue induced by intermittent sprinting on the MPF of the medial and lateral hamstring muscles. METHODS: Fifteen recreationally active males completed 18 × 20m overground sprints. Maximal strength (concentric and eccentric knee flexor and concentric knee extensor) was determined isokinetically at the velocities of ±180.s-1 and ±60.s- while hamstring muscle activation was assessed using surface electromyography, before and 15 minutes after the running protocol. RESULTS: Overground intermittent running caused a significant reduction in eccentric knee flexor strength (27.2 Nm; 95% CI = 11.2 to 43.3; p=0.0001) but not concentric strength (9.3 Nm; 95% CI = -6.7 to 25.3; P=0.6361). Following the overground running, MPF of the lateral hamstrings showed a significant decline eccentrically (0.86; 95% CI = 0.59 to 1.54; P=0.038) and concentrically (0.76; 95%CI = 0.66 to 0.83; P=0.039). Similar declines in MPF were also noted in the medial hamstrings eccentrically (1.54; 95% CI = 0.59 to 7.9; P=0.005) and concentrically (1.18; 95% CI = 0.44 to 6.8; P=0.040). CONCLUSION: Whilst sprint running induced fatigue led to a eccentric specific reduction in knee flexor torque, MPF was suppressed across both contraction modes. This would indicate that factors associated with the decline in MPF do not appear to explain the contraction mode-specific loss of strength after intermittent sprints. This would implicate other central mechanisms, such as declines in voluntary activation, in explaining the eccentric specific decline in strength seen following sprint running.

How do perceptions of risk associated with driving while fatigued and perceptions of effectiveness of countermeasures effect willingness to engage in fatigue reducing countermeasures?

Sleep-related and fatigue-related driving is an important contributory factor in fatal and serious injury crashes - Accounts for approx 19% - Similar in magnitude to drink driving

A longitudinal study of health-related quality of life, fatigue and physical activity in chronic kidney disease patients

This study assessed the health-related quality of life (HRQoL), fatigue and physical activity levels of 28 persons with chronic kidney disease (CKD) on initial administration of an erythropoietin stimulating agent, and at 3 months, 6 months and 12 months. The sample comprised of 15 females and 13 males whose ages ranged from 31 to 84 years. Physical activity was measured using the Human Activity Profile (HAP): Self-care, Personal/Household work, Entertainment/Social, Independent exercise. Quality of life was measured using the SF-36 which gives scores on physical health (physical functioning, role-physical, bodily pain and general health) and mental health (vitality, social functioning, role-emotional and emotional well-being). Fatigue was measured by the Fatigue Severity Scale (FSS). Across all time points the renal sample engaged in considerably less HAP personal/household work activities and entertainment/social activities compared to healthy adults. The normative sample engaged in three times more independent/exercise activities compared to renal patients. One-way Repeated measures ANOVAs indicated a significant change over time for SF-36 scales of role physical, vitality, emotional well-being and overall mental health. There was a significant difference in fatigue levels over time [F(3,11) = 3.78, p<.05]. Fatigue was highest at baseline and lowest at 6 months. The more breathlessness the CKD patient reported, the fewer activities undertaken and the greater the reported level of fatigue. There were no significant age differences over time for fatigue or physical activity. Age differences were only found for SF-36 mental health at 3 months (t=-2.41, df=14, p<.05). Those younger than 65 years had lower emotional well-being compared to those aged over 65. Males had poorer physical health compared to females at 12 months. There were no significant gender differences on mental health at any time point. In the management of chronic kidney disease, early detection of a person’s inability to engage in routine activities due to fatigue is necessary. Early detection would enable timely interventions to optimise HRQoL and independent exercise.

Effects of mixed-method cooling on recovery of medium-fast bowling performance in hot conditions on consecutive days

This investigation examined physiological and performance effects of cooling on recovery of medium-fast bowlers in the heat. Eight, medium-fast bowlers completed two randomised trials, involving two sessions completed on consecutive days (Session 1: 10-overs and Session 2: 4-overs) in 31 ± 3°C and 55 ± 17% relative humidity. Recovery interventions were administered for 20 min (mixed-method cooling vs. control) after Session 1. Measures included bowling performance (ball speed, accuracy, run-up speeds), physical demands (global positioning system, counter-movement jump), physiological (heart rate, core temperature, skin temperature, sweat loss), biochemical (creatine kinase, C-reactive protein) and perceptual variables (perceived exertion, thermal sensation, muscle soreness). Mean ball speed was higher after cooling in Session 2 (118.9 ± 8.1 vs. 115.5 ± 8.6 km · h−1; P = 0.001; d = 0.67), reducing declines in ball speed between sessions (0.24 vs. −3.18 km · h−1; P = 0.03; d = 1.80). Large effects indicated higher accuracy in Session 2 after cooling (46.0 ± 11.2 vs. 39.4 ± 8.6 arbitrary units [AU]; P = 0.13; d = 0.93) without affecting total run-up speed (19.0 ± 3.1 vs. 19.0 ± 2.5 km · h−1; P = 0.97; d = 0.01). Cooling reduced core temperature, skin temperature and thermal sensation throughout the intervention (P = 0.001–0.05; d = 1.31–5.78) and attenuated creatine kinase (P = 0.04; d = 0.56) and muscle soreness at 24-h (P = 0.03; d = 2.05). Accordingly, mixed-method cooling can reduce thermal strain after a 10-over spell and improve markers of muscular damage and discomfort alongside maintained medium-fast bowling performance on consecutive days in hot conditions.

Effect of carbohydrate ingestion and ambient temperature on muscle fatigue development in endurance-trained male cyclists

The aim of the present study was to determine the effect of carbohydrate (CHO; sucrose) ingestion and environmental heat on the development of fatigue and the distribution of power output during a 16.1-km cycling time trial. Ten male cyclists (Vo(2max) = 61.7 +/- 5.0 ml.kg(-1).min(-1), mean +/- SD) performed four 90-min constant-pace cycling trials at 80% of second ventilatory threshold (220 +/- 12 W). Trials were conducted in temperate (18.1 +/- 0.4 degrees C) or hot (32.2 +/- 0.7 degrees C) conditions during which subjects ingested either CHO (0.96 g.kg(-1).h(-1)) or placebo (PLA) gels. All trials were followed by a 16.1-km time trial. Before and immediately after exercise, percent muscle activation was determined using superimposed electrical stimulation. Power output, integrated electromyography (iEMG) of vastus lateralis, rectal temperature, and skin temperature were recorded throughout the trial. Percent muscle activation significantly declined during the CHO and PLA trials in hot (6.0 and 6.9%, respectively) but not temperate conditions (1.9 and 2.2%, respectively). The decline in power output during the first 6 km was significantly greater during exercise in the heat. iEMG correlated significantly with power output during the CHO trials in hot and temperate conditions (r = 0.93 and 0.73; P < 0.05) but not during either PLA trial. In conclusion, cyclists tended to self-select an aggressive pacing strategy (initial high intensity) in the heat.

Quality of life in chronic fatigue syndrome

Whilst the debilitating fatigue experienced in patients suffering from Chronic Fatigue Syndrome (CFS) results in a subjective marked impairment in functioning, little research has investigated the impact of this disorder on quality of life. Forty-seven subjects with a confirmed diagnosis of CFS and 30 healthy controls were compared using the Sickness Impact Profile (SIP). A subgroup of subjects were interviewed regarding the impact CFS has had on their social and family relationships, work and recreational activities. Results from both the SIP and the interview revealed that CFS subjects had significantly impaired quality of life, especially in areas of social functioning. These findings highlight the importance of addressing the social isolation and loss of role functioning experienced by CFS sufferers.

A prospective longitudinal survey of fatigue self-management behaviors in patients with advanced cancer

Background: Fatigue is a distressing symptom experienced by approximately 74-88% of patients with advanced cancer. Although there have been advances in managing fatigue with the use of a range of pharmacologic and non-pharmacologic strategies, fatigue is not well-managed in patients with advanced cancer. Objectives: For patients with advanced cancer, the aims of the study were to examine the self-management (SM) behaviours associated with fatigue; the perceived effectiveness of these SM behaviours, and the socio-demographic and clinical factors influencing the effectiveness of these SM behaviours. Methodology: A prospective longitudinal study was undertaken with 152 patients with metastatic breast, lung, colorectal and prostate cancer experiencing fatigue (>3/10) over a two month period. SM behaviours associated with fatigue, medical/demographic characteristics, social support, depression, anxiety, self-efficacy and other symptoms were assessed. Results: Findings indicate that on most fatigue severity measures, levels of fatigue increased slightly over time. On average, participants used nine fatigue SM behaviours at each time point. Participants reported that the most effective SM behaviours were ‘pacing their activities during the day’, ‘planning activities to make the most of energy’, ‘taking short sleeps’, ‘doing things that distract them from their fatigue’, and ‘doing things to improve sleep at night’. Factors associated with the increased effectiveness of fatigue SM behaviours included higher self-efficacy, higher education level, lower levels of depressive symptoms, and lower functional status. These results can be used to inform the design of future interventions to support the use of effective fatigue SM behaviours in this population.

Fatigue self-management : a survey of Chinese cancer patients undergoing chemotherapy

Aims and objectives. To examine Chinese cancer patients’ fatigue self-management, including the types of self-management behaviours used, their confidence in using these behaviours, the degree of relief obtained and the factors associated with patients’ use of fatigue self-management behaviours. Background. Fatigue places significant burden on patients with cancer undergoing chemotherapy. While some studies have explored fatigue self-management in Western settings, very few studies have explored self-management behaviours in China. Design. Cross-sectional self- and/or interviewer-administered survey. Methods. A total of 271 participants with self-reported fatigue in the past week were recruited from a specialist cancer hospital in south-east China. Participants completed measures assessing the use of fatigue self-management behaviours, corresponding self-efficacy, perceived relief levels plus items assessing demographic characteristics, fatigue experiences, distress and social support. Results. A mean of 4_94 (_2_07; range 1–10) fatigue self-management behaviours was reported. Most behaviours were rated as providing moderate relief and were implemented with moderate self-efficacy. Regression analyses identified that having more support from one’s neighbourhood and better functional status predicted the use of a greater number of self-management behaviours. Separate regression analyses identified that greater neighbourhood support predicted greater relief from ‘activity enhancement behaviours’ and that better functional status predicted greater relief from ‘rest and sleep behaviours’. Higher self-efficacy scores predicted greater relief from corresponding behaviours. Conclusions. A range of fatigue self-management behaviours were initiated by Chinese patients with cancer. Individual, condition and environmental factors were found to influence engagement in and relief from fatigue self-managementbehaviours. Relevance to clinical practice. Findings highlight the need for nurses to explore patients’ use of fatigue self-management behaviours and the effectiveness of these behaviours in reducing fatigue. Interventions that improve patients’ self-efficacy and neighbourhood supports have the potential to improve outcomes from fatigue self-management behaviours.

Do nursing interventions targeting concurrent symptoms hold promise for managing fatigue in patients with advanced cancer?

TO THE EDITOR: It was with great interest that I read two recent articles by de Raaf et al1, and Bruera et al2. These authors are to be congratulated for completing two of the very few high quality randomized trials that evaluate complex interventions for managing fatigue in patients with advanced cancer. de Raaf et al conducted a non-blinded RCT with 152 patients with advanced cancer and reported significant reduction of fatigue in patients who received a nurse-led monitoring and protocol-guided treatment of physical symptoms compared with those who received usual care1. Patients who received this intervention experienced a significant improvement over time in general fatigue, at one-month follow-up and two-month follow-up. Another recent RCT conducted with 141 patients with advanced cancer by Bruera et al2 did not find any benefits of a nursing telephone intervention that involved systematic symptom assessment/management, medication review, psychosocial support and patient education in fatigue reduction, compared to those who received a control telephone intervention conducted by a non-professional...

Quality of life, fatigue and activity in Australians with chronic kidney disease : a longitudinal study

Aims and objectives This study sought to determine the relationship between health related quality of life (HRQoL), fatigue and activity levels of people with anaemia secondary to chronic kidney disease (CKD) over a 12 month period following the introduction of an erythropoietin stimulating agent (ESA). Background CKD occurs in five stages and it is a complex chronic illness which severely impacts on an individual’s HRQoL, and ability to perform everyday activities. Fatigue is also a common symptom experienced by people with CKD. Design and methods Using a longitudinal repeated measures design, 28 people with CKD completed the SF-36, human activity profile and fatigue severity scale at the commencement of an ESA and then at 3, 6 and 12 months. Results Over a 12 month period, people reported a significant change in HRQoL in relation to role physical, vitality, mental health/emotional well-being and overall mental health. However activity levels did not significantly improve during that time. Both the amount of breathlessness and level of fatigue were highest at baseline and declined over time. Both fatigue and breathlessness were correlated with less reported general health over time. Conclusion Renal nurses, in dialysis units and CKD outpatient clinics, have repeated and frequent contact with people with CKD over long periods of time, and are in an ideal position to routinely assess fatigue and activity levels and to institute timely interventions. Early detection would enable timely nursing interventions to optimise HRQoL and independent activity. Relevance to Clinical Practice Drawing on rehabilitation nursing interventions could assist renal nurses to minimize the burden of fatigue and its impact on simple everyday activities and a person’s quality of life. These interventions are important for people who are living at home and could assist in lowering the burden on home support services.

Relationship of moderate and low isometric lumbar extension through architectural and muscular activity variables: a cross sectional study

Background No study relating the changes obtained in the architecture of erector spinae (ES) muscle were registered with ultrasound and different intensities of muscle contraction recorded by surface EMG (electromyography) on the ES muscle was found. The aim of this study was analyse the relationship in the response of the ES muscle during isometric moderate and light lumbar isometric extension considering architecture and functional muscle variables. Methods Cross-sectional study. 46 subjects (52% men) with a group mean age of 30.4 (±7.78). The participants developed isometric lumbar extension while performing moderate and low isometric trunk and hip extension in a sitting position with hips flexed 90 degrees and the lumbar spine in neutral position. During these measurements, electromyography recordings and ultrasound images were taken bilaterally. Bilaterally pennation angle, muscle thickness, torque and muscle activation were measured. This study was developed at the human movement analysis laboratory of the Health Science Faculty of the University of Malaga (Spain). Results Strong and moderate correlations were found at moderate and low intensities contraction between the variable of the same intensity, with correlation values ranging from 0.726 (Torque Moderate – EMG Left Moderate) to 0.923 (Angle Left Light – Angle Right Light) (p < 0.001). This correlation is observed between the variables that describe the same intensity of contraction, showing a poor correlation between variables of different intensities. Conclusion There is a strong relationship between architecture and function variables of ES muscle when describe an isometric lumbar extension at light or moderate intensity. Keywords: Ultrasonography; Surface electromyography; Thickness; Pennation angle; Erector spinae

Efficacy of proxy definitions for identification of fatigue/sleep-related crashes : an Australian evaluation

Fatigue/sleepiness is recognised as an important contributory factor in fatal and serious injury road traffic incidents (RTIs), however, identifying fatigue/sleepiness as a causal factor remains an uncertain science. Within Australia attending police officers at a RTI report the causal factors; one option is fatigue/sleepiness. In some Australian jurisdictions police incident databases are subject to post hoc analysis using a proxy definition for fatigue/sleepiness. This secondary analysis identifies further RTIs caused by fatigue/sleepiness not initially identified by attending officers. The current study investigates the efficacy of such proxy definitions for attributing fatigue/sleepiness as a RTI causal factor. Over 1600 Australian drivers were surveyed regarding their experience and involvement in fatigue/sleep-related RTIs and near-misses during the past five years. Driving while fatigued/sleepy had been experienced by the majority of participants (66.0% of participants). Fatigue/sleep-related near misses were reported by 19.1% of participants, with 2.4% being involved in a fatigue/sleep-related RTI. Examination of the characteristics for the most recent event (either a near miss or crash) found that the largest proportion of incidents (28.0%) occurred when commuting to or from work, followed by social activities (25.1%), holiday travel (19.8%), or for work purposes (10.1%). The fatigue/sleep related RTI and near-miss experience of a representative sample of Australian drivers does not reflect the proxy definitions used for fatigue/sleepiness identification. In particular those RTIs that occur in urban areas and at slow speeds may not be identified. While important to have a strategy for identifying fatigue/sleepiness related RTIs proxy measures appear best suited to identifying specific subsets of such RTIs.