Cancer-related fatigue (CRF) is the most common side effect of cancer and cancer treatment. CRF prevalence is up to 50% in breast cancer patients and can continue several years after cancer ...remission. This persistent subjective sense of exhaustion is multifactorial. Numerous parameters have been evidenced to be related to CRF across biological, physical, psychological, social and/or behavioral dimensions. Although CRF has been studied for many years, the majority of previous studies focused on only one dimension, i.e., physical function. Moreover, few studies investigated CRF longitudinally with repeated measures. These are the two main obstacles that limit the understanding of CRF mechanisms. The purpose of this study is to create a biopsychosocial model of CRF with simultaneous and longitudinal anthropometric, clinical, biological, physical, psychological and sociological parameters.
BIOCARE FActory is a multicentric prospective study that will consist of an 18-month follow-up of 200 women diagnosed with breast cancer. Four visits will be scheduled at diagnosis, after treatments, and 12 and 18 months after diagnosis. The same procedure will be followed for each visit. Each session will be composed of anthropometric data collection, a semi-structured interview, cognitive tests, postural control tests, neuromuscular fatigability tests and a cardiorespiratory fitness test. Clinical and biological data will be collected during medical follow-ups. Participants will also complete questionnaires to assess psychological aspects and quality of life and wear an actigraphy device. Using a structural equation modeling analysis (SEM), collected data will build a biopsychosocial model of CRF, including the physiological, biological, psychological, behavioral and social dimensions of CRF.
This study aims to highlight the dynamics of CRF and its correlates from diagnosis to post treatment. SEM analysis could examine some relations between potential mechanisms and CRF. Thus, the biopsychosocial model will contribute to a better understanding of CRF and its underlying mechanisms from diagnosis to the aftermaths of cancer and its treatments.
This study is registered at ClinicalTrials.gov ( NCT04391543 ), May 2020.
Purpose
As a subjective symptom, cancer-related fatigue is assessed via patient-reported outcomes. Due to the inherent bias of such evaluation, screening and treatment for cancer-related fatigue ...remains suboptimal. The purpose is to evaluate whether objective cancer patients’ hand muscle mechanical parameters (maximal force, critical force, force variability) extracted from a fatiguing handgrip exercise may be correlated to the different dimensions (physical, emotional, and cognitive) of cancer-related fatigue.
Methods
Fourteen women with advanced breast cancer, still under or having previously received chemotherapy within the preceding 3 months, and 11 healthy women participated to the present study. Cancer-related fatigue was first assessed through the EORTC QLQ-30 and its fatigue module. Fatigability was then measured during 60 maximal repeated handgrip contractions. The maximum force, critical force (asymptote of the force-time evolution), and force variability (root mean square of the successive differences) were extracted. Multiple regression models were performed to investigate the influence of the force parameters on cancer-related fatigue’s dimensions.
Results
The multiple linear regression analysis evidenced that physical fatigue was best explained by maximum force and critical force (
r
= 0.81;
p
= 0.029). The emotional fatigue was best explained by maximum force, critical force, and force variability (
r
= 0.83;
p
= 0.008). The cognitive fatigue was best explained by critical force and force variability (
r
= 0.62;
p
= 0.035).
Conclusion
The handgrip maximal force, critical force, and force variability may offer objective measures of the different dimensions of cancer-related fatigue and could provide a complementary approach to the patient reported outcomes.
This study analysed the muscle activity levels and patterns of the major thigh muscle activation during training sections at different intensities of on-water rowing. 9 experienced rowers performed 2 ...imposed-pace sections (B1 and B2) and 2 maximal-speed sections (start, 500 m) of on-water rowing. The knee angle, power output, mean torque and stroke rate were measured using specific instrumentation and were synchronised with surface electromyography signals of 5 superficial quadriceps and hamstring muscles. B1 and B2 sections were not significantly different regarding mechanical parameters and EMG activities, while the start phase induced large differences. The EMG patterns for B1, B2 were similar (cross-correlation coefficients (CC) ranged between 0.972-0.984) and the moderate CC found between both B1 and start (0.605-0.720) and B2 and start (0.629-0.720). Our results suggest that the hamstring muscles have a motor action and contribute to the power production during the leg drive. During an all-out 500 m section, a decrease in power and stroke rate was found (up to 20%). However, EMG patterns were not time shifted for all muscles. During the leg drive, the muscle activity levels of the quadriceps muscles were unchanged, while the activity of the hamstring muscles decreased.
Introduction Cette étude a pour but l’analyse de la stabilité posturale lors de la réalisation d’une deuxième tâche motrice, des tirs à la sarbacane. Matériel et méthode Trente-trois sujets ont ...participé à l’étude. Ils ont réalisé 2 enregistrements en condition bipodale statique, sans puis avec tirs. Les descripteurs étudiés sont de type spatio-temporels et fréquentiels. Résultats Nos résultats montrent, en condition de tir, une augmentation de la surface, de la vitesse, de la longueur et de l’énergie spectrale dans la bande des fréquences supérieures à 2 Hz. Discussion–conclusion Les valeurs supérieures des descripteurs de vitesse et de stabilité lors de l’enregistrement avec tirs montrent une diminution de la stabilité posturale en condition de double tâche d’ordre moteur. Ces résultats ne confirment pas ceux des travaux antérieurs (Maylor et al., 2001; Andersson et al., 2002) qui montraient une amélioration de l’équilibre postural lors de réalisation d’une double tâche d’ordre cognitive. L’amélioration ou la diminution de l’équilibre serait liée à la nature de la deuxième tâche exécutée. L’augmentation de l’énergie spectrale dans la bande des hautes fréquences montrerait une utilisation plus importante des boucles courtes avec participation du réflexe myotatique.
Abstract This study aimed to explore changes in the electrical activity distribution among synergist muscles involved in the maintenance of this bilateral multi-joint task. It also tested relations ...between changes in surface electromyographic (sEMG) parameters with endurance time. Eighteen subjects, trained and untrained in hiking, performed a submaximal (50% of maximal contraction) isometric hiking test until exhaustion. The electrical activity of main superficial muscles implicated in this posture was recorded bilaterally. Trained subjects sustained the hiking position for 315 ± 82 s, versus 225 ± 68 s for untrained subjects. Patterns of electrical activity and mean power frequency (MPF) were different between populations. MPF shift in abdominal muscles was higher than in other synergists for both groups. Although typical changes in sEMG parameters were observed, few relations with endurance time were found, and for untrained subjects only. Changes in the relative contribution among synergists were observed, mainly for trained subjects. It is hypothesized that the task (a complex multi-joint posture involving numerous joints and muscles) may allow some variability in the contribution of synergist muscles during fatigue especially for the trained group. This probably explains the absence of relationship between endurance time and sEMG changes for trained subjects.
The purposes of this study were to investigate the combined effects of age and obesity on gait and to analyze the relationship between age and obesity on ankle muscle activities during walking.
4 ...groups; the young non-obese control group (CG, n = 50, age = 31.8 ± 4.5 years; BMI = 21.4 ± 2.2 kg/m2), the young obese group (OB, n = 30, age = 35.4 ± 4.1 years; BMI = 38.6 ± 3.5 kg/m2), the non-obese older adults group (OA, n = 20, age = 76.1 ± 3.5 years; BMI = 24.4 ± 1.1 kg/m2) and the obese older adults group (OBOA, n = 20, age = 79.6 ± 5.7 years; BMI = 35.5 ± 2.7 kg/m2) walked on an instrumented gait analysis treadmill at their preferred walking speed. Spatiotemporal parameters, walking cycle phases, Vertical ground reaction force (GRFv) and center of pressure (CoP) velocity were sampled from the treadmill software. Electromyography (EMG) activity of the gastrocnemius medialis (GM), the soleus (SOL) and tibialis anterior (TA) were also collected during the walking test. A forward stepwise multiple regression analysis was performed to determine if body weight or age could predict ankle muscle activities during the different walking cycle phases.
Compared to OB, OBOA walked with higher CoP velocity, shorter stride, spending more time in support phase (p < .05). These manifestations were associated with higher TA and SOL activities during the 1st double support (1st DS) and higher TA activity during the single support (SS) (p < .05). Compared to OA, OBOA walked with lower GRFv, shorter and wider stride and spend more time in SU (p < .05). Moreover, SOL, TA and GM activities of OBOA were higher compared to OAG during 1st DS, SS and 2nd Double support (2nd DS), respectively (p < .05). During the 1ST DS, the stepwise multiple regression revealed that age accounted for 87% of the variance of TA activity. The addition of age contributed a further 16% to explain the variance TA activity. During the SS, age accounted for 64% and 46% of the variance of SOL and TA activity respectively. The addition of the body weight added further 15% and 66% of the variation of SOL and TA activity respectively. During the 2nd DS, body weight accounted for 86% of the variance and the addition of the body weight added a further 17% to explain the high level of GM.
Age in obese adults and obesity in older adults should be considered separately to evaluate neuromuscular responses during walking and, subsequently, optimize the modality of treatment and rehabilitation processes in obese individuals in order to reduce and/or prevent the risk of falls.
•Age and obesity result in cumulative gait pattern alterations.•Related-obesity neuromuscular responses are different between young and older adults.•Age in obese adults and obesity in older adults should be considered separately.
•Obesity is associated with altered postural control capacities.•Body weight is positively correlated with center of pressure displacements.•Obesity increases muscle coactivation at the ankle joint ...during postural control.•Body weight is positively correlated with ankle muscle coactivation.•Increased muscle coactivation could not be considered as a good adaptation.
It is well established that obesity is associated with deterioration in postural control that may reduce obese adults’ autonomy and increase risks of falls. However, neuromuscular mechanisms through which postural control alterations occur in obese adults remain unclear.
To investigate the effects of obesity on muscle coactivation at the ankle joint during static and dynamic postural control.
A control group (CG; n = 20; age = 32.5 ± 7.6 years; BMI = 22.4 ± 2.2 Kg/m²) and an obese group (OG; n = 20; age = 34.2 ± 5.6 years; BMI = 38.6 ± 4.1 Kg/m²) participated in this study. Static postural control was evaluated by center of pressure (CoP) displacements during quiet standing. Dynamic postural control was assessed by the maximal distance traveled by the CoP during a forward lean test. Electromyography activity data for the gastrocnemius medialis (GM), soleus (SOL) and tibialis anterior (TA) were collected during both quiet standing and forward lean tests. Muscle activities were used to calculate two separate coactivation indexes (CI) between ankle plantar and dorsal flexors (GM/TA and SOL/TA, respectively).
CoP displacements were higher in the OG than in the CG for quiet standing (p < 0.05). When leaning forward, the maximal distance of the CoP was higher in the CG than in the OG (p < 0.05). Only the CI value calculated for SOL/TA was higher in the OG than in the CG for both static and dynamic tasks (p < 0.05). The SOL/TA CI value in the OG was positively correlated with CoP displacements during quiet standing (r = 0.79; p < 0.05).
Obesity increases muscle coactivation of the soleus and tibialis anterior muscles at the ankle joint during both static and dynamic postural control. This adaptive neuromuscular response may represent a joint stiffening strategy for enhancing stability. Consequently, increased ankle muscle coactivation could not be considered as a good adaptation in obese adults.
Abstract Objectives This review aims to define the concept of neuromuscular fatigue and to present the current knowledge of the central and peripheral factors at the origin of this phenomenon. This ...review also addresses the literature that focuses on the mechanisms responsible for the adaption to neuromuscular fatigue. Method One hundred and eighty-two articles indexed in PubMed (1954–2010) have been considered. Results Neuromuscular fatigue has central and peripheral origins. Central fatigue, preponderant during long-duration, low-intensity exercises, may involve a drop in the central command (motor, cortex, motoneurons) elicited by the activity of cerebral neurotransmitters and muscular afferent fibers. Peripheral fatigue, associated with an impairment of the mechanisms from excitation to muscle contraction, may be induced by a perturbation of the calcium ion movements, an accumulation of phosphate, and/or a decrease of the adenosine triphosphate stores. To compensate for the consequent drop in force production, the organism develops several adaptation mechanisms notably implicating motor units. Conclusion Fatigue onset is associated with an alteration of the mechanisms involved in force production. Then, the interaction between central and peripheral mechanisms leads to a series of events that ultimately contribute to the observed decrease in force production.
The aim of the study was to investigate the influence of age and/or obesity on postural control, ankle muscle activities during balance testing and force production capacities.
4 groups; control ...group (CG; n = 25; age = 31.8 ± 7.5 years; BMI = 21.4 ± 2.5 kg/m2), obese group (OG; n = 25; age = 34.4 ± 9.5 years; BMI = 39.6 ± 5.4 kg/m2), elderly group (EG; n = 15; age = 77.1 ± 8.4 years; BMI = 24.4 ± 1.3 kg/m2) and obese elderly group (ObEG; n = 12; age = 78.6 ± 6.6 years; BMI = 34.5 ± 3.1 kg/m2) performed maximal voluntary contraction (MVC) before testing to calculate the maximal relative force of ankle plantar flexor (PF) and dorsal flexor (DF) muscles. Center of pressure (CoP) parameters and the electromyography (EMG) activity of PF and DF muscles were collected during MVC, quiet standing and limit of stability (LoS) testing along antero-posterior and medio-lateral axes.
Maximal relative force was higher in EG and ObEG than CG and OG, respectively (p < 0.001). CoP parameters, distance traveled along the antero-posterior axis and EMG activity of PF were higher in OG, EG and ObEG compared to CG (p < 0.001) and in EG compared to ObEG (p < 0.05).The EMG activity of PF was positively correlated with CoP parameters in OG and ObEG (r > 0.6; p < 0.05). Maximal relative force of PF (r > −0.6; p < 0.05) was negatively correlated with CoP parameters in ObEG and EG.
Obesity-related postural control alteration is associated with increased activity of PF. This neuromuscular adaptation may reflect deteriorations of the proprioceptive system and is likely additional to age-related muscular impairments. This may be a mechanism by which obesity increases postural control alterations in elderly.
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