Influence of Transcranial Direct Current Stimulation and Exercise on Physical Capacity and Gait in Multiple Sclerosis: A Cross-Over Pilot Study.

Physical capacity provides a link between disease or impairment and limitations in activity; in multiple sclerosis (MS), it is limited and decreased. The aim of this study was to study the effects of exercise and transcranial direct current stimulation (tDCS) on the left dorsolateral prefrontal cortex area in MS patients with fatigue and an impaired gait ability. A cross-over design was carried out on fifteen patients with two disability associations, but three were excluded. Before and after each intervention, the 6 min walk test (6MWT) and the 2 min walk test (2MWT) were used to assess walking ability and the Modified Fatigue Impact Scale (MFIS) was used to assess fatigue. A total of twelve patients were enrolled (48.0 median age, Kurtzke Disability Scale (EDSS) 3.66 ± 1.3): five females and seven males. After the application of the exercise program, significant improvements were observed in the 6MWT (p < 0.001, g = 0.159) and 2MWT (p < 0.001, g = 0.182). Furthermore, fatigue was significantly reduced after the application of the exercise program (p < 0.05, g = 0.742) and after tDCS (p < 0.05, g = 0.525). We could consider therapeutic exercise in the future to improve the walking ability and fatigue in MS patients. Furthermore, tDCS did not exert a significant improvement in walking ability, but it appeared to influence fatigue. Clinical trial registration code: ACTRN12622000264785.

The Effect of Combining Transcranial Direct Current Stimulation Treatment and an Exercise Program on Fragility in a Population with Multiple Sclerosis: Cross-Over Design Trial.

BACKGROUND: The relationship between fragility and neurological diseases is extensive and affects many patients with multiple sclerosis (MS), whose risk factors are related to fragility. OBJECTIVE: To study the effects of exercise and transcranial direct current stimulation (tDCS) in MS patients with fatigue from four dimensions: functional mobility, balance, fatigue, and depression. METHODS: A total of 12 patients who belonged to two associations of people with physical disabilities participated. Functional mobility, depression, balance, and fatigue were assessed before and after the intervention. Transcranial direct current stimulation and the exercise program were carried out over a 4-week period with a wash-out period of 5 months. RESULTS: After the application of tDCS, we found significant improvements in balance (p < 0.05, g = 0.632), depression (p < 0.05, g = 0.402), functional mobility (p < 0.05, g = 0.297), and fatigue (p < 0.05, g = 0.526). After the exercise program, significant improvements were shown in balance (p < 0.01, g = 0.418), depression (p < 0.001, g = 0.540), functional mobility (p < 0.01, g = 0.262), and fatigue (p < 0.01, g = 0.742). Two-way mixed-measures ANOVA showed that all variables improved in both groups, with significant differences over time but not between groups. Secondary analysis showed significant correlations between balance and functional mobility (r = 0.671, p = 0.017), depression and fatigue (r = 0.586, p = 0.044) and between intensity of rehabilitation and balance (r = 0.622, p = 0.031). CONCLUSION: Participating in an exercise program and receiving tDCS separately improved the variables of depression, balance, mobility, and fatigue.

Biological Approach in the Treatment of External Popliteal Sciatic Nerve (Epsn) Neurological Injury: Review.

The external popliteal sciatic nerve (EPSN) is the nerve of the lower extremity most frequently affected by compressive etiology. Its superficial and sinuous anatomical course is closely related to other rigid anatomical structures and has an important dynamic neural component. Therefore, this circumstance means that this nerve is exposed to multiple causes of compressive etiology. Despite this fact, there are few publications with extensive case studies dealing with treatment. In this review, we propose to carry out a narrative review of the neuropathy of the EPSN, including an anatomical reminder, its clinical presentation and diagnosis, as well as its surgical and biological approach. The most novel aspect we propose is the review of the possible role of biological factors in the reversal of this situation.

Influence of Transcranial Direct Current Stimulation and Exercise on Fatigue and Quality of Life in Multiple Sclerosis.

BACKGROUND: Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system that leads to a great deterioration in the quality of life. OBJECTIVE: We aimed to assess the effectiveness of two individual programs, one based on transcranial direct current stimulation (tDCS) and another based on the effect of physical exercise on fatigue and quality of life in patients with MS. METHODS: A total of 12 patients with relapsing-remitting and progressive secondary MS participated. Fatigue and quality of life were assessed before and after intervention. The exercise program and tDCS were carried out over a 4-week period, with a washout period of 5 months. RESULTS: The results show significant improvements in the different quality of life subscales after the application of tDCS, activities of daily living (r = 0.625; p = 0.037) (g = 0.465), psychological well-being (r = 0.856; p = 0.004) (g = 0.727) and coping (r = 0.904; p = 0.18) (g = 0.376), and in those after the application of exercise, activities of daily living (r = 0.853; p = 0.003) (g = 0.570) and psychological well-being (r = 0.693; p = 0.041) (g = 0.417). After the application of both therapies, more than 50% of the subjects did not have a positive fatigue score on the MFIS scale. CONCLUSION: The major findings suggest that the application of both therapies produces a beneficial effect with significant improvements in the quality of life of this sample.

A systematic review of temporomandibular disorder diagnostic methods.

Objective: To compile the screening tools used to study temporomandibular disorders (TMD), classify and analyze their potential application in the field of physiotherapy.Methods: All gathered data included randomized clinical trials on humans over 18 years of age pulled from three databases up to November 2019.Results: Nineteen articles were retained, in which the subjects included 1095 women and 385 men. The 32 valuation systems reported were classified as follows: direct, requiring observation and/or palpation in situ by a clinician, which can be subdivided into protocols and instrumental systems; and indirect, requiring neither observation nor palpation by a clinician, which can be subdivided into questionnaires and scales.Conclusion: In order to evaluate TMD, the best choice is to combine direct and indirect assessment methodologies. The valuation of pressure pain threshold with an algometer and Fonseca's Anamnestic Index in combination with Anamnestic Questionnaire CMD, respectively, seems to provide the best results.

Reading Performance Improvements in Patients with Central Vision Loss without Age-Related Macular Degeneration after Undergoing Personalized Rehabilitation Training.

PURPOSE: To evaluate the efficacy of a reading rehabilitation program (RRP) in patients with central visual loss (CVL) and assess the impact of the RRP on the quality of life (QoL). METHODS: The RRP included four in-office and 39 in-home training sessions over 6 weeks. Reading speed, duration, and font size were evaluated during each in-office session. The subjective perception of the QoL was assessed before and after the RRP using the short version of a questionnaire (World Health Organization Quality of Life). A control group who received advice about ocular conditions and low-vision aids also was included. RESULTS: Seventeen patients with Stargardt's disease (STGD), 11 with adult-onset foveomacular vitelliform dystrophy (AFVD), and eight with myopic macular degeneration (MMD) were included. The control group included five patients each with STGD, AFVD, and MMD. The respective mean corrected distance visual acuities (VAs) in patients with STGD, AFVD, MMD, and the control group were 0.57 ± 0.38, 0.51 ± 0.38, 0.49 ± 0.24, and 0.55 ± 0.25 logarithm of the minimum angle of resolution; the mean corrected near VAs were 0.89 ± 0.20, 1.08 ± 0.17, 0.99 ± 0.34, and 1.18 ± 0.37 (M notation) using low-vision aids. The reading speed, duration, and font size improved in all groups. The RRP groups obtained (p ≤ 0.01) greater improvements than the control group in each reading performance variable assessed. Patients with STGD obtained greater improvements in the subjective evaluation; the control group did not obtain noteworthy improvement in any domain. CONCLUSIONS: The RRP improved reading performance in patients with CVL and positively impacted the subjective perception of the QoL.

Adaptation of Perceptual Responses to Low-Load Blood Flow Restriction Training.

Martín-Hernández, J, Ruiz-Aguado, J, Herrero, AJ, Loenneke, JP, Aagaard, P, Cristi-Montero, C, Menéndez, H, and Marín, PJ. Adaptation of perceptual responses to low-load blood flow restriction training. J Strength Cond Res 31(3): 765-772, 2017-The purpose of this study was to determine the adaptive response of ratings of perceived exertion (RPE) and pain over 6 consecutive training sessions. Thirty subjects were assigned to either a blood flow restriction training (BFRT) group or a high-intensity resistance training (HIT) group. Blood flow-restricted training group performed 4 sets (30 + 15 + 15 + 15, respectively) of unilateral leg extension at an intensity of 20% one repetition maximum (1RM) while a restrictive cuff was applied to the most proximal part of the leg. The HIT group performed 3 sets of 8 repetitions with 85% 1RM. Ratings of perceived exertion and pain were assessed immediately after each exercise set along the 6 training sessions and were then averaged to obtain the overall RPE and pain per session. Statistical analyses showed significant main effects for group (p ≤ 0.05) and time (p < 0.001). Ratings of perceived exertion values dropped from session 1 to session 6 in both BFRT (8.12 ± 1.3 to 5.7 ± 1.1, p < 0.001) and HIT (8.5 ± 1.2 to 6.40 ± 1.2, p < 0.001). Similar results were observed regarding pain ratings (BFRT: 8.12 ± 1.3 to 5.90 ± 1.55, p < 0.001; HIT: 6.22 ± 1.7 to 5.14 ± 1.42, p < 0.01). Our results indicate that RPE was higher after HIT, whereas differences did not reach significance regarding pain. These perceptual responses were attenuated over time, and the time course of this adaptive response was similar between BFRT and HIT. In summary, BFRT induces a marked perceptual response to training, comparable with that observed with HIT. However, this response becomes attenuated with continuous practice, leading to moderate values of RPE and pain. Perceptual responses may not limit the application of BFRT to highly motivated individuals.

Free-Weight Augmentation With Elastic Bands Improves Bench Press Kinematics in Professional Rugby Players.

García-López, D, Hernández-Sánchez, S, Martín, E, Marín, PJ, Zarzosa, F, and Herrero, AJ. Free-weight augmentation with elastic bands improves bench press kinematics in professional rugby players. J Strength Cond Res 30(9): 2493-2499, 2016-This study aimed to investigate the effects of combining elastic bands to free weight resistance (EB + FWR) on the acceleration-deceleration and velocity profiles of the bench press in professional rugby players and recreationally trained subjects. Sixteen male subjects (8 rugby players and 8 recreationally trained subjects) were randomly assigned to complete 2 experimental conditions in a crossover fashion: EB + FWR and FWR. In both conditions, subjects performed 1 bench press set to volitional exhaustion with a load equivalent to the 85% of 1 repetition maximum (1RM). In the EB + FWR condition, the contribution of elastic resistance was approximately 20% of the selected load (85% 1RM). Results indicate that EB + FWR condition increased significantly the range of concentric movement in which the barbell is accelerated. This increase was significantly higher in rugby players (35%) in comparison with recreationally trained subjects (13%). Maximal velocity was also increased in EB + FWR (17%), when compared with FWR condition. These results suggest that when combined with variable resistance (i.e., EB), the external resistance seems to be more evenly distributed over the full range of motion, decreasing the need for dramatic deceleration at the end of the concentric phase. The present data also indicate that the kinematic benefits of an EB + FWR approach seems to be more prominent in athletes from modalities in which high level of strength and power are required (i.e., rugby players).

Influence of isolated or simultaneous application of electromyostimulation and vibration on leg blood flow.

PURPOSE: The aim of this study was to analyze the acute effects of isolated or simultaneously applied whole-body vibration (WBV) and electromyostimulation (ES) on the popliteal arterial blood velocity and skin temperature (ST) of the calf. METHODS: Thirteen healthy males were assessed in five different sessions. After a familiarization session, four interventions were applied in random order; WBV, ES, simultaneous WBV and ES (WBV+ES), and 30 s of WBV followed by 30 s of ES (WBV30/ES30). Each intervention consisted of 10 sets × 1 min ON + 1 min OFF. The subject was standing on the vibration platform (squat position, 30° knee flexion, 26 Hz, 5 mm peak-to-peak), and ES was applied on the gastrocnemius of both the legs (8 Hz, 400 µs). RESULTS: The WBV+ES intervention was the only one that maintained the mean blood velocity (MBV) elevated above baseline during the 10 sets, from set-1 (134.6 % p < 0.01) to set-10 (112.6 % p < 0.05). The combined interventions were the only ones that maintained the peak blood velocity (PBV) elevated above baseline during all the sets, from set-1 (113.5 % p < 0.001) to set-10 (88.8 % p < 0.01) and from set-1 (58.4 % p < 0.01) to set-10 (49.1 % p < 0.05) for WBV+ES and WBV30/ES30, respectively. CONCLUSION: The simultaneous application of WBV and ES produced a general greater increase in MBV and PBV than the application of each method alone or consecutive. This novel methodological proposal could be interesting in different fields such as sports or the rehabilitation process of different pathologies, to achieve an enhanced peripheral blood flow.

Effects of whole-body vibration on muscle architecture, muscle strength, and balance in stroke patients: a randomized controlled trial.

OBJECTIVE: The aim of the present study was to analyze the effects of whole-body vibration on lower limb muscle architecture, muscle strength, and balance in stroke patients during a period of 3 mos. DESIGN: The inclusion criteria were having had ischemic or hemorrhagic stroke at least 6 mos before the study and a National Institutes of Health Stroke Scale score of greater than 1 and less than 20. The patients were randomly divided into two groups: an experimental group (n = 11, six men and five women; age, 62.4 ± 10.7 yrs; height, 1.64 ± 0.07 m; mass, 69.4 ± 12.9 kg) and a sham group (n = 9, five men and four women; age, 64.4 ± 7.6 yrs; height, 1.62 ± 0.07 m; mass, 75.0 ± 15.8 kg). The experimental group received a whole-body vibration treatment, with an increase in frequency, sets, and time per set during 17 sessions. The sham group performed the same exercises as that of the experimental group but was not exposed to vibration. Outcome variables included the muscle architecture (the rectus femoris, the vastus lateralis, and the medial gastrocnemius), the maximal isometric voluntary contraction of the knee extensors, and the Berg Balance Scale. RESULTS: There were no significant differences between the groups on the primary outcomes of lower limb muscle architecture, muscle strength, and balance. CONCLUSIONS: It seems that whole-body vibration exercise does not augment the increase in neuromuscular performance and lower limb muscle architecture induced by isometric exercise alone in stroke patients.

Whole-body vibration applied during upper body exercise improves performance.

Whole-body vibration (WBV) training has exercisers perform static and dynamic resistance training exercises on a ground-based platform. Exposure to WBV exposure has demonstrated benefits and no effect on lower body strength, power, and performance. The aim of this study was to determine if WBV exposure (50 Hz, 2.51 mm) has any potentiating effects postexercise by measuring the kinematic variables of a set of upper body elbow-extensor exercise (70% one-repetition maximum [1RM]) to volitional exhaustion. Sixteen recreationally active students (12 male and 4 female) performed 3 different experimental conditions on separate days. Each condition had the subjects perform 1 set of elbow-extension exercise to fatigue with 1 of 3 WBV treatments: WBV simultaneously during the set (AE); 60 seconds after application of WBV for 30 seconds (RE); and no WBV (CTRL). Kinematic parameters of each repetition were monitored by linking a rotary encoder to the highest load plate. The mean velocity and acceleration throughout the set and perceived exertion were analyzed. A significant increase (p < 0.05) was observed in the mean velocity for the whole set in the AE condition vs. the CTRL condition. The mean acceleration was significantly higher (p < 0.05) in the AE condition in comparison with RE (increased by 45.3%) and CTRL (increased by 50.4%) conditions. The positive effect induced by WBV on upper-limb performance is only achieved when the stimulus is applied during the exercise. However, WBV applied 60 seconds before upper body exercise results in no benefit.

Maximal strength on different resistance training rowing exercises predicts start phase performance in elite kayakers.

This study aimed to examine the relationship existing between maximum strength values in 2 common resistance training row exercises (bilateral bench pull [BBP] and one-arm cable row [OACR]) and short sprint performance in elite kayakers. Ten junior kayakers (5 women and 5 men) were tested on different days for 1 repetition maximum (1RM) and maximal voluntary isometric contraction in both exercises. Moreover, a 12-m sprint kayak was performed in a dew pond to record split times (2, 5, and 10 m), peak velocity, distance completed considering the first 8 strokes, and mean acceleration induced by right blade and left blade strokes. No differences (p > 0.05) were observed when right and left arms were compared in sprint testing or strength testing variables. Maximal strength values in BBP and OACR were significantly correlated with short sprint performance variables, showing the bilateral exercise with slightly stronger correlation coefficients than the unilateral seated row. Moreover, the relationship between strength testing and sprint testing variables is stronger when maximal force is measured through a dynamic approach (1RM) in comparison with an isometric approach. In conclusion, maximal strength in BBP and OACR is a good predictor of the start phase performance in elite sprint kayakers, mainly the 1RM value in BBP.

Acute effects of whole-body vibration on neuromuscular responses in older individuals: implications for prescription of vibratory stimulation.

The aim of this study was to analyze surface electromyography activity (sEMG) and rating of perceived exertion (RPE) responses in different muscles while standing on a vibrating platform producing oscillations of different frequencies and amplitudes. Twenty community-dwelling older adults (79.6 ± 3.2 years) took part in the research. Subjects were exposed to 12 different vibration treatments of 15 seconds separated by 1 minute of rest in random order to check the influence of frequency (25, 35, and 45 Hz) and amplitude (1 mm [low] and 3.1 mm [high]) vibration on sEMG signal and RPE. Additionally, the use of a soft pad was also examined for its influence on these measures. Three-factor analysis of variance for RPE and both lower and whole-body sEMGs revealed a significant amplitude main effect (p < 0.01), and soft mat effect (p < 0.01), and a significant frequency main effect (p < 0.01). The major findings were that sEMG and RPE increased with the acceleration of the vibration; moreover, the increments of sEMG were highly correlated with RPE. The results of this study suggest that using the RPE method after each exercise would allow exercise and health professionals to assess the intensity levels that correspond to the level of the vibratory program in older adults.

Whole-body vibration alters blood flow velocity and neuromuscular activity in Friedreich's ataxia.

The purpose of this study was to investigate the effects of whole-body vibration (WBV) on blood flow velocity and muscular activity after different vibration protocols in Friedreich's ataxia (FA) patients. After two familiarization sessions ten patients received six 3 min WBV treatments depending on a combination of frequency (10, 20 or 30 Hz) and protocol (constant or fragmented). Femoral artery blood flow velocity, vastus lateralis (VL) and vastus medialis (VM) electromyography (EMG), and rate of perceived exertion were registered. Peak blood velocity was increased with respect to basal values after 1, 2 and 3 min of WBV (14·8%, 18·8% and 19·7%, respectively, P<0·001). Likewise, mean blood velocity was increased with respect to basal values after 1, 2 and 3 min of WBV (17·3%, 19·4% and 16·6%, respectively, P<0·001). EMG amplitude of VL and VM was increased (39% and 23%, respectively, P<0·05) and EMG frequencies decreased during the application of WBV. The results of this study suggest that higher frequencies (30 Hz) produce a greater increase in blood flow velocity and rate of perceived exertion. WBV is an effective method to increase blood flow and to activate muscle mass in patients with Friedreich's ataxia, and could therefore be considered to be incorporated in rehabilitation programs of this collective.

Effects of different magnitudes of whole-body vibration on arm muscular performance.

The purpose of this study was to analyze the effects of different vibration magnitudes via feet on the number of repetitions performed, mean velocity, and perceived exertion during a set of elbow-extension exercise to failure (70% 1 repetition maximum [1RM] load). Twenty recreationally active students (14 men and 6 women) performed, in 3 different days, 1 elbow-extension set applying randomly 1 of the 3 experimental conditions: high magnitude (HM; 50 Hz and 2.51 mmp-p; 98.55 mxs-2), low magnitude (LM; 30 Hz and 1.15 mmp-p; 20.44 m.s-2) or control (Control, without vibration stimulus). Results indicate that the vibration via feet provides superimposed stimuli for elbow-extensor performance, enhancing the total number of repetitions performed in the HM and LM conditions, which was significantly higher (p

Influence of "in series" elastic resistance on muscular performance during a biceps-curl set on the cable machine.

This study aimed to investigate the role of elastic resistance (ER) applied "in series" to a pulley-cable (PC) machine on the number of repetitions performed, kinematics parameters, and perceived exertion during a biceps-curl set to failure with a submaximal load (70% of the 1 repetition maximum). Twenty-one undergraduate students (17 men and 4 women) performed, on 2 different days, 1 biceps-curl set on the PC machine. Subjects were randomly assigned to complete 2 experimental conditions in a cross-over fashion: conventional PC mode or ER + PC mode. Results indicate ER applied "in series" to a PC machine significantly reduces (p < 0.05) the maximal number of repetitions and results in a smooth and consistent decline in mean acceleration throughout the set, in comparison to the conventional PC mode. Although no significant differences were found concerning intrarepetition kinematics, the ER trended to reduce (18.6%) the peak acceleration of the load. With a more uniformly distributed external resistance, a greater average muscle tension could have been achieved throughout the range of movement, leading to greater fatigue that could explain the lower number of maximal repetitions achieved. The application of force in a smooth, consistent fashion during each repetition of an exercise, while avoiding active deceleration, is expected to enhance the benefits of the resistance exercise, especially for those seeking greater increases in muscular hypertrophy.

Short-term effect of strength training with and without superimposed electrical stimulation on muscle strength and anaerobic performance. A randomized controlled trial. Part I.

The purpose of this study was to compare strength training with and without superimposed electromyostimulation (EMS) on muscle strength and anaerobic power. Twenty-eight subjects were assigned to: weight+EMS (ES), weight (VOL), or control group (CG). ES and VOL performed 4 training sessions per week during 4 weeks on a knee extension machine (8 sets; 8 repetitions; 1-second concentric phase from 90 degrees to 0 degrees, 1-second eccentric phase from 0 degrees to 90 degrees , 1-second rest at 90 degrees; 3-minute rest between sets; 70% maximal voluntary contraction). Group ES received EMS in the concentric phase of each action (120 Hz, 400 microseconds). Before training, after training, and 2 weeks after the end of the training (detraining), maximal voluntary contraction, squat jump, countermovement jump (CMJ), countermovement jump with free arms (CMJA), and 20-m sprint time were analyzed. After the training period, ES and VOL increased their muscle strength (40.2% and 31.4%, respectively, p<0.001). After the detraining period, this gain remained above baseline values for ES and VOL (49.1% and 24.5%, respectively, p<0.001). Changes in muscle strength between baseline and detraining were higher in ES than in VOL (p<0.01). Anaerobic performance was not affected by training in any group, but percentage change between baseline and after training suggests that the CMJ and CMJA with free arms performance were impaired in ES with respect to VOL and CG. Superimposed EMS onto voluntary contractions increases strength more than voluntary training alone; nevertheless, a detraining period should be respected to observe this delayed adaptation. To improve anaerobic power with superimposed EMS, a complementary and specific work such as plyometrics should be carried out.

Short-term effect of plyometrics and strength training with and without superimposed electrical stimulation on muscle strength and anaerobic performance: A randomized controlled trial. Part II.

The purpose of this study was to compare the effects of combined strength and plyometric training with or without superimposed electromyostimulation (EMS) on muscle strength and anaerobic power. Twenty-nine subjects were randomly assigned to weight+plyometrics+EMS (EP), weight+plyometrics (VP), and control group (CG). Weight+plyometrics+EMS and VP performed 2 plyometric sessions and 2 weight training sessions per week throughout 4 weeks on a knee extension machine. Weight+plyometrics+EMS received EMS throughout the concentric phase of each action (120 Hz, 400 microseconds). Before, after training, and 2 weeks after the end of the training (detraining), maximal voluntary contraction, squat jump, countermovement jump, countermovement jump with free arms, and 20-minute sprint time were analyzed. After the training period, EP and VP increased their muscle strength (28.6 and 22.3%, respectively; p<0.001). After the detraining period, this gain remained above baseline values (28.1 and 18.0%, respectively; p<0.001 and p<0.01). After training and detraining, muscle strength was higher in EP than in VP (p<0.05). Vertical jump height was not modified for whichever group or test, except for the countermovement jump height with free arms, where a decrease for EP was observed after training (-6.3%; p<0.001) and detraining (-5.5%; p<0.001). Sprint performance improved in all groups in the detraining test (-0.8%; p<0.05). If a low number of training sessions are carried out, superimposed EMS leads to a higher strength gain than voluntary training alone. However, if anaerobic power is an important aim of the training, EMS should be applied isometrically instead of superimposed EMS and combined with plyometrics.

Interset stretching does not influence the kinematic profile of consecutive bench-press sets.

This study was undertaken to examine the role of interset stretching on the time course of acceleration portion AP and mean velocity profile during the concentric phase of 2 bench-press sets with a submaximal load (60% of the 1 repetition maximum). Twenty-five college students carried out, in 3 different days, 2 consecutive bench-press sets leading to failure, performing between sets static stretching, ballistic stretching, or no stretching. Acceleration portion and lifting velocity patterns of the concentric phase were not altered during the second set, regardless of the stretching treatment performed. However, when velocity was expressed in absolute terms, static stretching reduced significantly (p <0.05) the average lifting velocity during the second set compared to the first one. Therefore, if maintenance of a high absolute velocity over consecutive sets is important for training-related adaptations, static stretching should be avoided or replaced by ballistic stretching.

Differences in electrical stimulation thresholds between men and women.

OBJECTIVE: Surface electrical stimulation (ES) of skeletal muscle is used in a variety of clinical settings in healthy and unhealthy subjects of both sexes. Although women generally present larger amounts of subcutaneous adipose tissue than men, which could limit current flow to the stimulated muscle, sex-related differences in ES current levels have not been clearly demonstrated to date. We report data from healthy men and women. METHODS: Sensory (current perception), motor (minimal knee extension torque production), and supramotor thresholds (10% of the maximal voluntary knee extension torque) and perceived pain during surface ES of the quadriceps femoris muscle were investigated in 40 healthy volunteers (20 men, 20 women). RESULTS: Sensory threshold was lower in women than in men (-43%; p < 0.001). Similarly, female muscles required lower current amplitudes to attain the supramotor threshold (-17%; p < 0.01). The Visual Analogue Scale pain score was significantly greater in women than in men at motor threshold (+112%; p < 0.01) but not at supramotor threshold (+36%; p > 0.05). INTERPRETATION: Collectively, our data demonstrate higher sensory and supramotor excitability to surface ES in female subjects and provide further evidence for a neurophysiological explanation for more pronounced pain perception in women. These observations may help clinicians to better understand the sex-specific response to ES and to design more rational stimulation treatments with the ultimate goal of optimizing patient care and safety.