Myoelectric activity and improvements in strength and hypertrophy are unaffected by the ankle position during prone leg curl exercise - a within person randomized trial.

To examine the effect of ankle position (i.e. gastrocnemius muscle length) on training outcomes during leg curl exercise, we recruited untrained and trained healthy adults to participate in two separate experiments. In Experiment 1, we studied the acute influence of ankle position on knee flexor myoelectric (EMG) activity during leg curl exercise in a group of trained and a separate group of untrained adults. In Experiment 2, we studied the effects of ankle position on knee flexors muscle thickness and torque across a 10-week training protocol in trained adults. We hypothesized that leg curl exercise with the ankle in a plantarflexed position would enhance EMG activity, muscular strength, and hamstrings muscle thickness. We randomized the legs within a person to perform leg curl exercise with one in a plantarflexed position and the other in a dorsiflexed position. Experiment 1 revealed no significant differences between ankle positions in the EMG activity of hamstring muscle in either group (all p > 0.05). Experiment 2 revealed a significant pre- to post-intervention increase in biceps femoris long head (BFLH) muscle thickness (p = 0.026) and isometric torque (p = 0.03), but there were no significant effects of the ankle position (p = 0.596) or interaction between ankle position and timepoint for these variables (p = 0.420). In sum, the ankle position did not have acute effects on hamstrings EMG activity, nor did it affect strength and hypertrophy adaptations after 10-weeks of leg curl exercise training. Interestingly, however, the limb which performed leg curl exercise in a dorsiflexed position performed a higher total training volume.Highlights Different ankle positions (i.e. dorsiflexion or plantarflexion) do not affect hamstrings EMG activity during prone leg curl exercise.Different ankle positions show similar adaptation in strength and hypertrophy of biceps femoris long head after 10 weeks of training.Training in the plantarflexed position may be useful for time-constrained individuals, allowing similar training adaptations with smaller training volume.

Differences in the cross-sectional area along the ankle tendons with both age and sex.

Increasing age appears to influence several morphologic changes in major tendons. However, the effects of aging on the cross-sectional area (CSA) of different ankle tendons are much less understood. Furthermore, potential differences in specific tendon regions along the length of the tendons have not been investigated in detail. Sixty healthy adult participants categorized by age as young (n = 20; mean ± SD age = 22.5 ± 4.5 years), middle-age (n = 20; age = 40.6 ± 8. 0 years), or old (n = 20; age = 69.9 ± 9.1 years), from both sexes, were included. The tendon CSA of tibialis anterior (TA), tibialis posterior (TP), fibularis (FT), and Achilles (AT) was measured from T1-weighted 1.5 T MR images in incremental intervals of 10% along its length (from proximal insertion) and compared between different age groups and sexes. The mean CSA of the AT was greater in the middle-age group than both young and old participants (p < 0.01) and large effect sizes were observed for these differences (Cohen's d > 1). Furthermore, there was a significant difference in CSA in all three groups along the length of the different tendons. Region-specific differences between groups were observed in the distal portion (90% and 100% of the length), in which the FT presented greater CSA comparing middle-age to young and old (p < 0.05). In conclusion, (1) great magnitude of morpho-structural differences was discovered in the AT; (2) there are region-specific differences in the CSA of ankle tendons within the three groups and between them; and (3) there were no differences in tendon CSA between sexes.

Eccentric Strength Assessment of Hamstring Muscles with New Technologies: a Systematic Review of Current Methods and Clinical Implications.

BACKGROUND: Given the severe economic and performance implications of hamstring injuries, there are different attempts to identify their risk factors for subsequently developing injury prevention strategies to reduce the risk of these injuries. One of the strategies reported in the scientific literature is the application of interventions with eccentric exercises. To verify the effectiveness of these interventions, different eccentric strength measurements have been used with low-cost devices as alternatives to the widespread used isokinetic dynamometers and the technically limited handheld dynamometers. Therefore, the purpose of the present systematic review was to summarize the findings of the scientific literature related to the evaluation of eccentric strength of hamstring muscles with these new technologies. METHODS: Systematic searches through the PubMed, Scopus, and Web of Science databases, from inception up to April 2020, were conducted for peer reviewed articles written in English, reporting eccentric strength of hamstrings assessed by devices, different to isokinetic and handheld dynamometers, in athletes. RESULTS: Seventeen studies were finally included in the review with 4 different devices used and 18 parameters identified. The pooled sample consisted of 2893 participants (97% male and 3% female: 22 ± 4 years). The parameters most used were peak force (highest and average), peak torque (average and highest), and between-limb imbalance (left-to-right limb ratio). There is inconsistency regarding the association between eccentric hamstrings strength and both injury risk and athletic performance. There is no standardized definition or standardization of the calculation of the used parameters. CONCLUSIONS: The current evidence is insufficient to recommend a practical guide for sports professionals to use these new technologies in their daily routine, due to the need for standardized definitions and calculations. Furthermore, more studies with female athletes are warranted. Despite these limitations, the eccentric strength of hamstring muscles assessed by different devices may be recommended for monitoring the neuromuscular status of athletes.

Contralateral effects of eccentric resistance training on immobilized arm.

This study compared the effects of contralateral eccentric-only (ECC) and concentric-/eccentric-coupled resistance training (CON-ECC) of the elbow flexors on immobilized arm. Thirty healthy participants (18-34 y) were randomly allocated to immobilization only (CTRL; n = 10), immobilization and ECC (n = 10), or immobilization and CON-ECC group (n = 10). The non-dominant arms of all participants were immobilized (8 h·day-1 ) for 4 weeks, during which ECC and CON-ECC were performed by the dominant (non-immobilized) arm 3 times a week (3-6 sets of 10 repetitions per session) with an 80%-120% and 60%-90% of one concentric repetition maximum (1-RM) load, respectively, matching the total training volume. Arm circumference, 1-RM and maximal voluntary isometric contraction (MVIC) strength, biceps brachii surface electromyogram amplitude (sEMGRMS ), rate of force development (RFD), and joint position sense (JPS) were measured for both arms before and after immobilization. CTRL showed decreases (P < .05) in MVIC (-21.7%), sEMGRMS (-35.2%), RFD (-26.0%), 1-RM (-14.4%), JPS (-87.4%), and arm circumference (-5.1%) of the immobilized arm. These deficits were attenuated or eliminated by ECC and CON-ECC, with greater effect sizes for ECC than CON-ECC in MVIC (0.29: +12.1%, vs -0.18: -0.1%) and sEMGRMS (0.31:17.5% vs -0.15: -5.9%). For the trained arm, ECC showed greater effect size for MVIC than CON-ECC (0.47 vs 0.29), and increased arm circumference (+2.9%), sEMGRMS (+77.9%), and RDF (+31.8%) greater (P < .05) than CON-ECC (+0.6%, +15.1%, and + 15.8%, respectively). The eccentric-only resistance training of the contralateral arm was more effective to counteract the negative immobilization effects than the concentric-eccentric training.

A dominância de membros interfere no equilíbrio de força muscular do joelho de corredores recreacionais? / Does the limb dominance interfere with knee muscle strength balance in recreational runners?

Introdução: cerca de 5% da população brasileira pratica corrida de rua, e a falta de preparo físico das pessoas para esse esporte contribui para o aumento no índice de lesões, sendo o joelho uma das articulações mais acometidas. Sabendo que os parâmetros musculares interferem diretamente no desempenho e que a destreza de membros pode suscitar inferências relativas ao aumento de força no membro dominante, torna-se importante avaliar a força e a relação de equilíbrio muscular do joelho destes atletas tanto no membro dominante quanto no contralateral. Objetivo: verificar o equilíbrio muscular dos extensores e flexores de joelho dominante e não dominante em corredores recreacionais. Metodologia: foram incluídos 111 indivíduos com idade entre 18 e 65 anos, de ambos os sexos, praticantes de corrida há pelo menos 4 meses contínuos, sem histórico de lesão nos últimos 3 meses. Os participantes foram entrevistados e encaminhados para a coleta da força muscular isocinética dos grupos extensor e flexor do joelho com protocolo de 60°/s, 180°/s e 300°/s. As variáveis de interesse estudadas foram: membro dominante, tempo de prática de corrida, torque máximo, trabalho total e potência. Foram calculados os Índices de Deficiência Muscular (IDM) sendo admitido como referencial de equilíbrio até 10% na diferença entre os membros. A pesquisa foi aprovada pelo Comitê de Ética em Pesquisa do Instituto de Ciências da Saúde da Universidade Federal da Bahia, sob parecer de nº 2.621.166. Resultados: o IDM indicou que 54,1% dos extensores de joelho estavam equilibrados e que 55,9% dos flexores de joelho encontravam-se numa relação de desequilíbrio muscular. Conclusão: a dominância de membros não é um fator ligado ao desequilíbrio de forças no membro inferior. Este achado de desequilíbrio de força entre joelhos pode estar ligado à predisposição de lesão e deve orientar as equipes multiprofissionais de saúde a definir um trabalho preventivo de treinamento muscular e esportivo.

Introduction: about 5% of the Brazilian population practices street running and the lack of physical fitness for this sport contributes to the increase in the injury rate, with the knee being one of the most affected joints. Knowing that muscle parameters directly interfere performance and that limb dexterity may lead to inferences regarding strength increase in the dominant limb, it is important to evaluate the strength and balance ratio of these athletes' knee in both dominant and contralateral limbs. Objective: to verify muscle balance of dominant and non-dominant knee extensors and flexors in recreational runners. Methodology: 111 individuals aged between 18 and 65 years old, male and female, who have been running for at least 4 continuous months, with no history of injury in the last 3 months, were included. Participants were interviewed and referred for the collection of isokinetic muscle strength of the knee extensor and flexor groups with a protocol of 60°/s, 180°/s and 300°/s. The variables of interest studied were: dominant limb, running practice time, maximum torque, total work and power. Muscle deficiency indices (MDI) were calculated and accepted as a balance reference up to 10% in the difference between the limbs. The research was approved by the Research Ethics Committee of the Institute of Health Sciences of the Federal University of Bahia, under technical advice no 2.621.166. Results: the MDI indicated that 54.1% of the knee extensors were balanced and 55.9% of the knee flexors were in a muscular imbalance ratio. Conclusion: limb dominance is not a factor related to lower limb imbalance of forces. This finding of strength imbalance between knees may be associated to injury predisposition and should guide multidisciplinary health teams to define preventive work on muscle and sports training

The effects of 6 weeks of constant-angle muscle stretching training on flexibility and muscle function in men with limited hamstrings' flexibility.

PURPOSE: The aim of the present study was to evaluate the effects of 6 weeks of a constant-angle hamstring muscle flexibility training on muscle-tendon stiffness and the range of motion (ROM) in young men with limited hamstring ROM. METHODS: 13 participants performed unilateral stretching training (EL), while the contralateral limb acted as control (CL). ROM, relative and peak passive torque, passive stiffness, dynamic knee flexion strength, and active optimum joint angle were assessed before and after the last training session. In addition, participants were tested during the first and last training sessions for first stretch sensation during the stretching procedure only in the EL. RESULTS: Straight-leg raise and isokinetic knee ROM tests (both p < 0.0001; from 59.4 ± 8.1 to 70.3 ± 9.8, from 28.3 ± 7.6 to 18.5 ± 5.2, respectively) and peak passive torque (p = 0.001; from 53.1 ± 11.7 to 64.9 ± 12.3) increased only in EL and no changes in relative passive torque, passive stiffness, dynamic knee flexion strength, and active optimum joint angle (p > 0.05) were observed. At the point of first stretch sensation, significant increases in passive torque (p = 0.004) and angle (p < 0.001) were found from pre- to post-training. CONCLUSION: The flexibility training induced significant increases in ROM alongside increases in peak passive torque (stretch tolerance) and the ROM at which stretch was first perceived. However, this occurred without changes in muscle-tendon mechanical properties or transfer to the untrained limb (CL). These results suggest that limb-specific ROM increases were underpinned by neural adaptations.

Multicomponent Training Program with High-Speed Movement Execution of Ankle Muscles Reduces Risk of Falls in Older Adults.

The purpose of this study was to investigate the effects of multicomponent training program, designed to improve the torque around the ankle joint performing high-speed movement execution, on healthy older adults. Participants were balanced by torque around the ankle joint and randomly allocated to either exercise (n = 12, 69.7 ± 4.8 years, 74.6 ± 16.8 kg, 1.63 ± 0.10 m) or control group (CG) (n = 14, 70.86 ± 6.48 years; 73.5 ± 13.4 kg, 1.56 ± 0.05 m). The exercise group (EG) performed a multicomponent training of resistance, agility, and coordination exercises, focusing on the plantar flexor muscles during 12 weeks (3 days per week). Outcome measures were torque (plantar flexion and extension), reactive capacity (Step test), and functional mobility (gait and timed up and go [TUG] test). The training program was induced to increase peak torque of extensor muscles around the ankle joint to EG (Δ = 50%; d = 1.59) compared to the CG. Such improvement was converted to reactive capacity improvements considering the decrease in the execution time of the Swing phase and in the Total time of the Step test (Δ = 19%; d = 0.93, Δ = 14%; d = 1.02, respectively). Gains in functional mobility were verified by the increase of the walking speed (Δ = 15%; d = 1.37) and by the smaller time of execution of TUG test (Δ = 17%; d = 1.73) in the EG. Therefore, the multicomponent training was effective to reduce or to reverse muscular age-related declines, which are associated with functional capacity and reduction of fall risk in older adults.

Tenosinovitis inespecífica en granos de arroz de los tendones flexores de la mano / Ténosynovite non spécifique d'aspect en grains de riz des tendons fléchisseurs de la main / Non-specific flexor tendons tenosynovitis in rice grains of the hand

La tenosinovitis con cuerpos libres en forma de granos de arroz es una afección muy infrecuente que se presenta, generalmente, asociada a artritis reumatoide o tuberculosis. Los casos no asociados a estas enfermedades son extremadamente raros. Se presenta un paciente masculino de 62 años de edad, intervenido quirúrgicamente por un síndrome del túnel carpiano derecho hace 7 años. En aquel momento se le realizó una apertura del retináculo transverso del carpo y una sinovectomía de los tendones flexores. La biopsia sinovial reportó una "sinovitis crónica". Evolucionó satisfactoriamente durante los primeros 4 años, luego comenzó a presentar nuevamente los síntomas compresivos del nervio mediano y un aumento progresivo del volumen en la cara anterior de la muñeca. El ultrasonido mostró una marcada hipertrofia sinovial de los tendones flexores a nivel de la muñeca. Los estudios neurofisiológicos reportaron daño axonal y mielínico en las fibras del nervio mediano derecho. Se le realizó una nueva intervención donde se visualizó la hipertrofia sinovial y abundantes cuerpos libres en forma de granos de arroz agrupados en sacos sinoviales. Se le descomprimió el túnel carpiano, se resecaron los cuerpos libres y se le hizo una sinovectomía amplia. El resultado de la biopsia fue una sinovitis inespecífica con cuerpos libres en granos de arroz. Después de dos años de operado el paciente está asintomático.

Tenosynovitis with loose rice grain-like structures is a very rare condition that usually presents associated with rheumatoid arthritis or tuberculosis. Cases not associated with these diseases are extremely rare. A 62-year-old male patient underwent surgery for a right carpal tunnel syndrome seven years ago. At that time, an opening of the transverse retinaculum of the carpus and synovectomy of the flexor tendons were performed. Synovial biopsy reported "chronic synovitis". It evolved satisfactorily during the first four years; then the patient began to present again the compressive symptoms of the median nerve and progressive increase in volume in the anterior aspect of the wrist. The ultrasound showed marked synovial hypertrophy of the flexor tendons at the level of the wrist. Neurophysiological studies reported axonal and myelin damage in the fibers of the right median nerve. A new intervention was performed. Synovial hypertrophy was visualized and abundant free loose rice grain-like structures grouped in synovial sacs. The carpal tunnel was decompressed, the free bodies were resected and wide synovectomy was performed. The result of the biopsy was non-specific synovitis with free rice grain-like structures. After two years of surgery, the patient is asymptomatic.

La ténosynovite à corps étrangers libres d'aspect en grains de riz est une affection très peu fréquente, étant généralement associée à l'arthrite rhumatoïde ou à la tuberculose. Les cas non associés à ces maladies sont extrêmement rares. Le cas d'un patient âgé de 62 ans, atteint de syndrome du canal carpien droit, et traité chirurgicalement il y a sept ans, est présenté. En ce moment-là, il a subi une incision du ligament transverse du carpe (rétinaculum) et une synovectomie des tendons fléchisseurs. La biopsie synoviale a dévoilé une «synovite chronique¼. L'évolution a été satisfaisante au cours des quatre premières années; puis après la compression du nerf médian et l'inflammation progressive de la face antérieure du poignet ont réapparues. L'échographie a montré une marquée hypertrophie synoviale des tendons fléchisseurs au niveau du poignet. Les examens neurophysiologiques ont révélé un dommage axonal et myélinique des fibres du nerf médian droit. Dans la nouvelle intervention effectuée, une hypertrophie synoviale et plusieurs corps étrangers d'aspect en grains de riz groupés en bourses synoviales ont été remarqués. Une décompression du canal carpien, une résection des corps étrangers et une large synovectomie ont été réalisées. La biopsie a repéré une synovite non spécifique à corps étrangers libres en forme de grains de riz. Le patient reste encore asymptomatique depuis deux ans.

Texture analysis of ultrasound images is a sensitive method to follow-up muscle damage induced by eccentric exercise.

The grey level of co-occurrence matrix (GLCM) is a texture analysis approach accounting for spatial distribution of the pixels from an image and can be a promising method for exercise-induced muscle damage (EIMD) studies. We followed up the time changes of two GLCM texture parameters and echo intensity (EI) on ultrasound images after eccentric contractions. Thirteen untrained women performed two sets of ten elbow flexions eccentric contractions. Ultrasound images were acquired at baseline and 24 h, 48 h, 72 h and 96 h after exercise. Two GLCM texture parameters were calculated for the brachialis muscle: contrast (CON) and correlation (COR). Peak torque, EI, muscle thickness (MT) and soreness were measured. The peak torque and soreness decreased immediately after the intervention in comparison with all the measures. MT increased immediately after the intervention remaining for 72 h (P<0·05). Significant increases (P<0·05) were observed for COR (48, 72 and 96 h) and EI only at 72 and 96 h. The increasing COR represents high similarity between grey levels, which could be observed on US images after few days on eccentric training for elbow flexors.

Passive stiffness of the ankle and plantar flexor muscle performance after Achilles tendon repair: a cross-sectional study.

BACKGROUND: Deficits in ankle muscle strength and ankle stiffness may be present in those subjects who underwent surgical treatment for an Achilles tendon rupture. The presence of these long-term deficits may contribute to a lower performance during daily activities and may be linked to future injuries. OBJECTIVE: To compare the ankle passive stiffness and the plantar flexor muscle performance in patients who underwent unilateral surgical treatment of Achilles tendon rupture with nonsurgical subjects. METHOD: Twenty patients who underwent unilateral surgical treatment of Achilles tendon rupture [surgical (SU) group], and twenty nonsurgical subjects [non-surgical (NS) group] participated in this study. The ankle passive stiffness was evaluated using a clinical test. The concentric and eccentric plantar flexors performance (i.e. peak torque and work) was evaluated using an isokinetic dynamometer at 30°/s. RESULTS: The surgical ankle of the surgical group presented lower stiffness compared to the non-surgical ankle (mean difference=3.790; 95%CI=1.23-6.35) and to the non-dominant ankle of the non-surgical group (mean difference=-3.860; 95%CI=-7.38 to -0.33). The surgical group had greater absolute asymmetry of ankle stiffness (mean difference=-2.630; 95%CI=-4.61 to -0.65) and greater absolute asymmetry of concentric (mean difference=-8.3%; 95%CI=-13.79 to -2.81) and eccentric (mean difference=-6.9%; 95%CI=-12.1 to -1.7) plantar flexor work compared to non-surgical group. There was no other difference in stiffness and plantar flexor performance. CONCLUSION: Patients who underwent surgical repair of the Achilles tendon presented with long-term (1 year or more) deficits of ankle stiffness and asymmetries of ankle stiffness and plantar flexor work in the affected ankle compared to the uninjured side in the surgical group and both sides on the nonsurgical group.

Twitch potentiation induced by two different modalities of neuromuscular electrical stimulation: implications for motor unit recruitment.

INTRODUCTION: We tested the hypothesis that twitch potentiation would be greater following conventional (CONV) neuromuscular electrical stimulation (50-µs pulse width and 25-Hz frequency) compared with wide-pulse high-frequency (WPHF) neuromuscular electrical stimulation (1-ms, 100-Hz) and voluntary (VOL) contractions, because of specificities in motor unit recruitment (random in CONV vs. random and orderly in WPHF vs. orderly in VOL). METHODS: A single twitch was evoked by means of tibial nerve stimulation before and 2 s after CONV, WPHF, and VOL conditioning contractions of the plantar flexors (intensity: 10% maximal voluntary contraction; duration: 10 s) in 13 young healthy subjects. RESULTS: Peak twitch increased (P<0.05) after CONV (+4.5±4.0%) and WPHF (+3.3±5.9%), with no difference between the 2 modalities, whereas no changes were observed after VOL (+0.8±2.6%). CONCLUSIONS: Our results demonstrate that presumed differences in motor unit recruitment between WPHF and CONV do not seem to influence twitch potentiation results.

Efeitos do alongamento ativo excêntrico dos músculos flexores do joelho na amplitude de movimento e torque / Effects of an active eccentric stretching program for the knee flexor muscles on range of motion and torque

OBJETIVO: Avaliar a amplitude de movimento (ADM) e o torque flexor e extensor do joelho após a realização de um programa de alongamento ativo excêntrico dos músculos flexores do joelho. MATERIAIS E MÉTODOS: Trinta e quatro voluntários (23 mulheres e 11 homens), 34,42±9,3 anos, realizaram um programa de alongamento ativo excêntrico dos músculos flexores do joelho na postura em pé, que consistiu de sete repetições de um minuto com 30 segundos de descanso entre as repetições. O programa de alongamento foi realizado duas vezes por semana, durante quatro semanas. A ADM de extensão e o torque flexor e extensor do joelho foram avaliados no dinamômetro isocinético pré e pós-programa de alongamento. O torque foi avaliado nos modos isométrico e isocinético concêntrico e excêntrico a 30º/s e 60º/s. RESULTADOS: Houve aumento na ADM de 53,7±13º para 30,1±16º (p=0,0001), no torque isométrico flexor de 89±32Nm para 93±33Nm (p=0,01) e extensor de 178±67Nm para 187±73Nm (p=0,006). O torque flexor concêntrico e excêntrico a 30º/s aumentou de 90±31Nm para 96±31Nm (p=0,001) e de 100±34Nm para 105±35Nm (p=0,01), respectivamente. O torque extensor concêntrico a 60º/s aumentou de 144±51Nm para 151±58Nm (p=0,02) e o excêntrico a 30º/s de 175±71Nm para 189±73Nm (p=0,01). CONCLUSÕES: O programa de alongamento proposto foi efetivo para aumentar a flexibilidade dos músculos alongados e torque dos grupos musculares agonistas (alongados) e seus antagonistas.

OBJECTIVE: To evaluate the changes in knee range of motion (ROM) and torque of knee flexor and extensor muscles after an active eccentric stretching program for the knee flexor muscles. METHODS: Thirty-four volunteers (23 women and 11 men), aged 34.42±9.3 years, performed an active eccentric stretching program for the knee flexor muscles in the standing posture, consisting of seven repetitions of one minute each, with 30 seconds of resting between them. The stretching program was performed twice a week, for four weeks. Knee extension ROM and the torque of the knee flexor and extensor muscles were evaluated using an isokinetic dynamometer before and after the stretching program. The torque was evaluated in the isometric, isokinetic concentric and eccentric modes at 30º/s and 60º/s. RESULTS: There was an increase in ROM from 53.7±13º to 30.1±16º (p=0.0001), in isometric torque of the flexors from 89±32Nm to 93±33Nm (p=0.01) and of the extensors from 178±67Nm to 187±73Nm (p=0.006). The concentric and eccentric torque of the flexors at 30º/s increased from 90±31Nm to 96±31Nm (p=0.001) and from 100±34Nm to 105±35Nm (p=0.01), respectively. The concentric torque of the extensors at 60º/s increased from 144±51Nm to 151±58Nm (p=0.02), and the eccentric torque at 30º/s increased from 175±71Nm to 189±73Nm (p=0.01). CONCLUSIONS: The stretching program proposed was effective for increasing the flexibility of the stretched muscles and the torque of the agonist (stretched) muscle groups and their antagonists.

Incidence of palmaris longus muscle absence in nigerian population / Incidencia de la ausencia del músculo palmar largo en la población de Nigeria

A lot has been reported about variation of palmaris longus muscle in journals and conventional textbooks. The incidence of palmaris longus muscle absence among people of the six geo-political zones of Nigeria was evaluated using 600 subjects. 31.25 percent (187 subjects) lack palmaris longus muscleon either of the forearms. 12.5 percent (75 subjects) shows unilateral absence and 18.75 percent (112 subjects) shows bilateral absence. 25 percent (150) of subjects lacks palmaris longus muscleon their right forearms while 25 percent also lacks it on their left forearms. 6 percent (37) shows double tendons of palmaris longus muscleon both forearms. Highest incidence of absence was recorded among people of South-West zone.

Mucho se ha informado acerca de la variación del músculo palmar largo en revistas y libros de texto convencionales. La incidencia de ausencia del músculo palmar largo entre las personas de las seis zonas geo-políticas de Nigeria se evaluó usando 600 sujetos. 31,25 por ciento (187 sujetos) no tenían músculo palmar largo en cualquiera de los antebrazos, 12,5 por ciento (75 sujetos) mostró ausencia unilateral y 18,75 por ciento (112 sujetos) mostró ausencia bilateral. 25 por ciento (150) de los sujetos carece de músculo palmar largo en su antebrazo derecho, mientras que el 25 por ciento carece de él también en su antebrazo izquierdo. 6 por ciento (37) muestra dobles tendones de músculo palmar largo en ambos antebrazos. Mayor incidencia de ausencia se registró entre las personas de la zona Sur-Oeste.

Estudo eletromiográfico dos músculos motores primários da articulação do joelho na mesa romana: estudo de caso / Eletromyography study of the primary motors muscles of the knee articulation executed in roman table: study of case

Através dos estudos eletromiográficos é que se tem conhecido a efetiva participação dos músculos esqueléticos. Participaram do estudo 05 sujeitos do sexo masculino, na faixa etária entre 17 e 22 anos, praticantes de musculação. Foram utilizados eletrodos de superfície. Os músculos reto femoral, vasto lateral e vasto medial foram analisados no movimento de extensão do joelho realizado sentado na mesa romana; os músculos bíceps femoral, semimembranoso e semitendinoso foram analisados no movimento de flexão do joelho em decúbito ventral na mesa romana. Os resultados expressos em RMS foram: 543,86 (±127,39) para o músculo semimembranoso, 400,08 (±124,10) para o semitendinoso, 222,92 (±69,28) o valor do bíceps femoral, 288,12 (±152,4) para o músculo reto femoral, 215,63 (±117,30) para o músculo vasto lateral e 190,58 (±75,01) o valor do vasto medial. As cargas máximas utilizadas foram maiores no movimento de extensão do joelho. Os resultados demonstraram maior participação dos músculos flexores do joelho quando coparado com os extensores.

Through the electromyography studies it is that is had known the effective participation of the skeletal muscle. They participated in the study five subject of the masculine sex, in the age group among 17 and 22 years. Surface electrodes were used. The vastus lateralis, vastus medialis, rectus femoris muscles was analyzed in the extension movement of the knee, sat down in the roman table; the biceps femoris, semimembranosus and semitendinosus muscles was analyzed in the flexion movement of the knee, in decubitus ventralis, in the roman table. The results, expressed in RMS, were: 543,86 (±127,39) for the semimembranosus muscle, 400,08 (±124,10) for semitendinosus, 222,92 (±69,28) the value of the biceps femoris muscles, 288,12 (±152,4) for the rectus femoris, 215,63 (±117,30) for the vastus lateralis muscle and 190,58 (±75,01) the value of vastus medialis. The used maximum loads were larger in the extension movement of the knee. The results demonstrated larger participation of the flexors muscles of he knee when compared with the extensors muscles.