Reliability of Corticospinal and Motoneuronal Excitability Evaluation During Unfatiguing and Fatiguing Cycling Exercise.

INTRODUCTION: Central nervous system excitability depends on the task performed, muscle group solicited, and contraction type. However, little is known on corticospinal and motoneuronal excitability measured during locomotor exercise. This study aimed at determining the reliability of motor-evoked potentials (MEP) and thoracic motor-evoked potentials (TMEP) in dynamic mode during unfatiguing and fatiguing cycling exercise. METHODS: Twenty-two participants completed four visits. Visit 1 comprised familiarization and a maximal incremental test to determine maximal power output (Wmax). The remaining visits encompassed unfatiguing evaluations, which included 8 brief bouts of moderate (50% Wmax) and high intensity cycling (80% Wmax). In each bout, a set of two TMEPs, five MEPs and one M-max were obtained. Subsequently, a fatiguing exercise to exhaustion at 80% Wmax was performed, with four sets of measurements 3 min through the exercise and 4 additional sets at exhaustion, both measured at 50% Wmax. RESULTS: Intraclass correlation coefficients (ICCs) for 5, 10, 15 and 20 MEP·Mmax-1 revealed excellent reliability at both intensities and during fatiguing exercise (ICC ≥ 0.92). TMEP·Mmax-1 showed ICCs ≥0.82 for moderate and high intensity, and it was not affected by fatigability. Overall standard error of measurement was 0.090 [0.083, 0.097] for MEP·Mmax-1 and 0.114 [0.105, 0.125] for TMEP·Mmax-1. A systematic bias associated to the number of stimulations, especially at high intensity, suggested the evaluation itself may be influenced by fatigability. A mean reduction of 8% was detected in TMEP·Mmax-1 at exhaustion. CONCLUSIONS: Motoneuronal and corticospinal excitability measured in dynamic mode presented good to excellent reliability in unfatiguing and fatiguing exercise. Further studies inducing greater fatigability must be conducted to assess the sensitivity of central nervous system excitability during cycling.

Reliability and measurement error of a maximal voluntary toe plantarflexion measurement process.

Despite the growing interest, information regarding the psychometric properties of maximal voluntary isometric toe plantarflexion force and rate of force development (RFD) is lacking. Hence, we investigate the test-retest reliability and measurement error of these outcome measurement instruments measured with a custom-built dynamometer. Twenty-six healthy adults participated in a crossed design with four sessions separated by 5-7 days. RFD was quantified using manual onset and calculating the impulse and the slope in the following time windows: 0-50 ms, 0-100 ms, 0-150 ms, 0-200 ms, 0-250 ms. We estimated the systematic bias of the mean, the intraclass correlation coefficient (ICC) and standard error of measurement (SEM) from the agreement and consistency models. The ICC and the SEM agreement for maximal voluntary isometric toe plantarflexion force along the perpendicular axis were respectively 0.87 (95%CI: 0.76, 0.93) and 27 N (22, 32), while along the resultant of the perpendicular and anterior posterior axis they were 0.85 (0.73, 0.92) and 29 N (23, 35). The results of the consistency model were similar as the estimated variance for session was closer to zero. A systematic bias of the mean between session 1 and 3 was found. For the RFD variables, the ICC agreement ranged from 0.35 to 0.65. The measurement process was found to be reliable to assess maximal voluntary isometric toe plantarflexion force but not RFD. However, a familiarization session is mandatory and these results need to be confirmed in less coordinated (e.g. aging population) individuals.

Influence of age on postural control during dual task: a centre of pressure motion and electromyographic analysis.

BACKGROUND: Dual task influences postural control. A cognitive task seems to reduce muscle excitation during a postural balance, especially in older adults (OA). AIM: The aim of this study is to evaluate the effect of three cognitive tasks on muscle excitation and static postural control in OA and young adults (YA) in an upright posture maintenance task. METHODS: 31 YA and 30 OA were evaluated while performing a modified Romberg Test in five different conditions over a force plate: open eyes, closed eyes, spatial-memory brooks' test, counting backwards aloud test and mental arithmetic task. The surface electromyographic signals of Tibialis anterior (TA), Lateral Gastrocnemius (GL), Peroneus Longus (PL), and Erector Spinae (ES) was acquired with an 8-channel surface electromyographic system. The following variables were computed for both the electromyographic analysis and the posturographic assessment: Root mean square (RMS), centre of pressure (CoP) excursion (Path) and velocity, sway area, RMS of the CoP Path and 50%, 95% of the power frequency. Mixed ANOVA was used to detect differences with group membership as factor between and type of task as within. The analysis was performed on the differences between each condition from OE. RESULTS: An interaction effect was found for Log (logarithmic) Sway Area. A main effect for task emerged on all posturographic variables except Log 95% frequencies and for Log PL and ES RMS. A main effect for group was never detected. DISCUSSION AND CONCLUSION: This study indicates a facilitating effect of mental secondary task on posturographic variables. Non-silent secondary task causes increase in ES and TA muscle activation and a worsening in static postural control performance.

Lower Limb Strength Profile in Elderly with Different Pathologies: Comparisons with Healthy Subjects.

Sarcopenia and muscle strength reduction are a frequent disorder in non-communicable chronic diseases. The aims of this study are: a) to verify if the absolute and relative to body weight muscle strength of lower limb is affected by the presence of pathology; b) to verify if the trends are different among knee and ankles joints. One-hundred and forty-five elderly were recruited (16 liver transplant recipients, 48 kidney transplant recipients, 52 elderly with obesity, 30 healthy elderly). Muscular strength of lower limb was evaluated. Evaluation protocol included maximal isometric knee extension, maximal isokinetic knee extension and flexion, maximal isokinetic ankle (both right and left) extension and flexion. A statistically significant interaction between measurement and group membership was found for absolute strength measure (F(4.23, 170.56) = 3.316, p = 0.011, partial η2 (η2p) = 0.076), and relative strength measure(F(4.44, 174.72) = 16.407, p < 0.01, partial η2 (η2p) = 0.294). Elderly patients living with kidney transplants showed the lower level of absolute muscular strength, while relative muscular strength is mainly lacking in the elderly with obesity. The strength profile of elderly subjects is affected by obesity, liver transplantation, and kidney transplantation.

Postural control data from prevalent kidney transplant patients with and without history of falls.

This article presents data from a research paper entitled "Postural balance, muscle strength, and history of falls in end-stage renal disease patients living with a kidney transplant: a cross-sectional study" available in Journal Gait and Posture [1]. In this article, we reported the minimal detectable changes at the 95% level of confidence (MDC95) of postural balance variables measured in eyes open (EO) and eyes closed (EC) conditions, with a stabilometric platform, in 59 kidney transplant (KT) recipients (mean age= 53.2 ±â€¯11 years). In addition, we also performed receiver operating characteristics (ROC) curve analysis to explore the ability of postural balance measures to discriminate fallers and non-fallers (history of falls: yes or no). Sensitivity, specificity and area under the curve (AUC) of mean center of pressure velocity (CoPv), sway area (SA), center of pressure range of displacement in the anterior-posterior (AP) and medio-lateral (ML) directions were calculated. These data can be used by researchers aiming to design psychometric studies of postural balance in KT patients and they also provide clinicians with information on possible prioritization of outcome assessment for future fall-risk research in this clinical population.

Postural balance, muscle strength, and history of falls in end-stage renal disease patients living with a kidney transplant: A cross-sectional study.

BACKGROUND: End-stage renal disease patients living with a kidney transplant (KT) often present with frailty, functional disability, and mobility impairments that may result in a high risk of falls. Postural balance and muscle strength are implicated in the etiology of falls in the geriatric population, and both may be impaired in KT patients. RESEARCH QUESTION: We conducted a cross-sectional investigation to estimate the prevalence of falls, as well as to explore the association between postural balance, muscle strength and history of falls in end-stage renal disease patients living with a KT. METHODS: Fifty-nine prevalent KT patients (age = 53.2 ±â€¯11 years) were enrolled in this cross-sectional study. Participants were classified as fallers/non-fallers and underwent an objectively-measured assessment of postural balance on a stabilometric platform in eyes open (EO), eyes closed (EC), and dual-task (DT) conditions. Center of pressure (CoP) variables were taken for the analysis. In addition, participants underwent isometric (IM) and isokinetic (IK) assessments of lower limb muscle strength on a multi-joint evaluation system. RESULTS: Thirty-four percent of the study participants reported at least one fall in the previous 12 months. In logistic regression analysis, CoP velocity in EO (OR: 1.23, 95 % CI: 1.06-1.43, p = .007), and IK ankle dorsiflexion strength (OR: 0.87, 95 % CI: 0.77-0.99, p = .034) were independently associated with increased odds of falling. SIGNIFICANCE: This cross-sectional study indicates that patients living with a KT presented with a prevalence of falls indicative of a high risk of falling. Postural balance and muscle strength are exercise-modifiable factors and further research is warranted to establish to what extent these measures may be implicated in the etiology of falling in this patient group.

Reliability of an Integrated Inertial Sensor for the Continuous Measurement of Active Cervical Range of Motion in a Group of Younger and Elderly Individuals.

The aim of this study was to evaluate the test-retest reliability of an integrated inertial sensor (IIS) for cervical range of motion assessment. An integrated inertial sensor was placed on the forehead center of thirty older adults (OA) and thirty younger adults (YA). Participants had to perform three continuous rotations, lateral bandings and flexion-extensions with their head. Test-retest reliability was assessed after 7 days. YA showed moderate to good agreement for rotation (0.54-0.82), lateral bending (0.74-0.8), and flexion-extension (0.74-0.81) movements and poor agreement for zero point (ZP). OA showed moderate to good agreement for rotation (0.65-0.86), good to excellent agreement in lateral bending (0.79-0.92), and poor to moderate agreement for flexion-extension (0.37-0.72). Zero point showed poor to moderate agreement. In conclusion, we can affirm that this IIS is a reliable device for cervical range of motion assessment in young and older adults; on the contrary, the ZP seems to be unreliable and the addition of an external reference point could help the subject to solve this shortcoming and reduce possible biases.

Exercise prescription and tailored physical activity intervention in onco-hematology inpatients, a personalized bedside approach to improve clinical best practice.

Therapy of hematological malignancies lasts for long periods implicating various complications. The chemotherapy induces fatigue and forces bed rest. These features strongly contribute to a general impairment of the physical efficiency. Oppositely, an increase of physical exercise can prevent or reduce this weakening. Few trials examined the efficacy of an exercise in onco-hematological inpatients, during their hospitalization. Therefore, this study aimed to determine the feasibility of an inter-hospital intervention and the beneficial role of a tailored exercise program in the maintenance of the physical function in onco-hematological inpatients. The study included 42 patients, which were allocated in two groups. In the intervention group (IG) a tailored exercise protocol during patient's hospitalization was administered. Exercise protocol was focused on development of strength, balance control, and flexibility; sessions were directly performed in the patient's hospital room everyday for 15 to 30 minutes. Exercise was supervised by an exercise specialist and driven by a multimedia support. Control group (CG) remained physically inactive for all period of hospitalization. To examine the interaction between the two situations (T0 and T1 ) and the two groups (IG and CG) for all dependent variables, a 2 × 2 within-subjects contrasts model analysis of variance was applied. Within groups analysis displayed significant differences in grip and leg strength and in static balance control (P < 0.05) with medium to very large effect size. Results from this investigation showed that a tailored exercise protocol administered to hospitalized onco-hematological patients was feasible and efficient to promote the maintenance of their physical function, improving clinical best practice including exercise to the traditional treatment. Moreover, the magnitude of the difference between the IG and the CG underlined the importance to invite and stimulate patients to workout to preserve the physical function, counteracting side effects of chemotherapy treatments with a concurrent reduction in bed rest syndrome.

Nordic Walking Promoted Weight Loss in Overweight and Obese People: A Systematic Review for Future Exercise Prescription.

The aim of this systematic review was to analyze the effect of Nordic Walking (NW) on anthropometric parameters, body composition, cardiovascular parameters, aerobic capacity, blood sample, and glucose tolerance in overweight and obese subjects. The main keywords "Nordic Walking" or "Pole Walking", associated with either "obese", "obesity", "overweight", or "weight loss" were used on the online database MEDLINE, PubMed, SPORTDiscus and Scopus. Additionally, references of the studies included were screened to identify eligible articles. Applying the inclusion and exclusion criteria, ten manuscripts were considered as eligible for this review. The results of the studies were categorized in several domains with regard to "anthropometric parameters and body composition", "cardiovascular parameters and aerobic capacity", and "blood sample and glucose tolerance". The results showed positive effects on the anthropometric parameters, body composition, cardiovascular parameters, blood sample, and glucose tolerance. The greatest improvements were observed in supervised and high weekly frequency of NW interventions. NW could be considered as an effective modality through which to involve the obese in physical activity. For weight loss, NW should be prescribed 4-5 times per week, at least 60 min per session, preferably combined with diet control.

Physical Exercise Is Confirmed to Reduce Low Back Pain Symptoms in Office Workers: A Systematic Review of the Evidence to Improve Best Practices in the Workplace.

This systematic review aimed to analyze the effects of a physical exercise (PE) program on low back pain (LBP) symptoms of office workers and the modification of flexibility and range of motion (ROM), muscular strength, and quality of life (QoL). A literature research was performed on PubMed, Scopus, MEDLINE, and SPORTDiscus from April to May 2018. The keyword "low back pain" was associated with "office worker" OR "VDT operators" OR "office employees" OR "workplace" AND "exercise", OR "exercise therapy" OR "physical activity". Inclusion criteria were a home- or work-based exercise protocol for office workers with LBP symptoms and pre- to post-intervention evaluation of LBP symptoms. Three researchers independently examined all abstracts. The modified Cochrane methodological quality criteria were used for quality assessment and 11 articles were included. Exercise protocols were performed from 6 weeks to 12 months, 1-5 day per week, lasting 10-60 min for each session. Physical Exercise in the workplace improved all the considered outcomes. The best improvement was recorded in supervised protocols and in video-supported protocols performed in the workplace. The effect may be generated with small duration sessions during the working day, with only 10-15 min of adapted exercise to be performed 3-5 days per week.