Fábio Juner Lanferdini

Neuromuscular electrical stimulation (NMES) reduces structural and functional losses of quadriceps muscle and improves health status in patients with knee osteoarthritis

Knee osteoarthritis (OA) is associated with quadriceps atrophy and weakness, so muscle strengthening is an important point in the rehabilitation process. Since pain and joint stiffness make it often difficult to use conventional strength exercises, neuromuscular electrical stimulation (NMES) may be an alternative approach for these patients. This study was aimed at (1) identifying the associations of knee OA with quadriceps muscle architecture and strength, and (2) quantifying the effects of a NMES training program on these parameters. In phase 1, 20 women with knee OA were compared with 10 healthy female, asymptomatic, age‐matched control subjects. In phase 2, 12 OA patients performed an 8‐week NMES strength training program. OA patients presented smaller vastus lateralis thickness (11.9 mm) and fascicle length (20.5%) than healthy subjects (14.1 mm; 24.5%), and also had a 23% smaller knee extensor torque compared to the control group. NMES training increased vastus lateralis thickness (from 12.6 to 14.2 mm) and fascicle length (from 19.6% to 24.6%). Additionally, NMES training increased the knee extensor torque by 8% and reduced joint pain, stiffness, and functional limitation. In conclusion, OA patients have decreased strength, muscle thickness, and fascicle length in the knee extensor musculature compared to control subjects. NMES training appears to offset the changes in quadriceps structure and function, as well as improve the health status in patients with knee OA.

Effects of intra-session exercise sequence during water-based concurrent training.

The aim was to investigate the effects of the intra-session exercise order during water-based concurrent training on the neuromuscular adaptations in young women. 26 women (25.1±2.9 years) were placed into 2 groups: resistance prior to (RA) or after (AR) aerobic training. Subjects performed resistance (sets at maximal effort) and aerobic training (exercises at heart rate corresponding to the second ventilatory threshold) twice a week over 12 weeks, performing both exercise types in the same training session. Upper (elbow flexion) and lower-body (knee extension) one-repetition maximum test (1RM) and peak torque (PT) were evaluated. The muscle thickness (MT) of upper (sum of MT of biceps brachii and brachialis) and lower-body (sum of MT of vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris) was determined by ultrasonography. Moreover, the maximal electromyographic activity (EMG) of upper (biceps brachii) and lower-body (sum of EMG of vastus lateralis and rectus femoris) was measured. Both RA and AR groups increased the upper and lower-body 1RM and PT, while the lower-body 1RM increases observed in the RA was greater than AR (43.58±14.00 vs. 27.01±18.05%). RA and AR showed MT increases in all muscles evaluated, while the lower-body MT increases observed in the RA were also greater than AR (10.24±3.11 vs. 5.76±1.88%). There were increases in the maximal EMG of upper and lower-body in both RA and AR, with no differences between groups. Performing resistance prior to aerobic exercise during water-based concurrent training seems to optimize the lower-body strength and hypertrophy.

Relação entre os níveis de atividade física e qualidade de vida de idosos sedentários e fisicamente ativos

INTRODUCAO: O nivel de atividade fisica pode interferir na capacidade funcional, influenciando na saude e qualidade de vida dos idosos. OBJETIVO: Comparar os niveis de atividade fisica e qualidade de vida entre idosos que praticam exercicios fisicos regulares e idosos sedentarios, e verificar a associacao entre o nivel de atividade fisica e a qualidade de vida nos grupos. METODOS: Foram avaliados 50 idosos do sexo feminino (n= 34) e masculino (n= 16), com idade de 70,24±8,8 anos, divididos em dois grupos - sedentarios (G1, n=25) e praticantes de exercicios fisicos regulares (G2, n=25). Realizou-se entrevista individual, aplicando-se Anamnese; Questionario Internacional de Atividade Fisica (IPAQ) e Perfil de Saude de Nottingham (PSN). A normalidade dos dados foi testada por meio do teste de Shapiro-Wilk, utilizando-se ainda os testes U de Mann-Whitney (qualidade de vida) e Qui-Quadrado (nivel de atividade fisica). A associacao entre o nivel de atividade fisica e a qualidade de vida foi avaliada por meio do teste ETA2 (p<0,05). RESULTADOS: Em relacao ao PSN, o G1 apresentou reduzida qualidade de vida, comparado ao G2. Ja para o IPAQ, somente o G1 apresentou diferenca significativa (p=0,00) em relacao ao G2. Alem disso, para o G1, 50% do nivel de atividade fisica foram associados a qualidade de vida, enquanto o G2 apresentou 64%. CONCLUSOES: De acordo com os resultados encontrados no presente estudo, idosos praticantes de exercicios fisicos e idosos sedentarios apresentam bom nivel de atividade fisica. Entretanto, idosos praticantes de exercicios regulares possuem maior nivel de atividade fisica, explicando a melhor qualidade de vida neste grupo.

Specificity of strength gains after 12 weeks of isokinetic eccentric training in healthy men

Although previous studies have demonstrated that skeletal muscle adaptations were specific to the types of stimuli, eccentric training studies presented controversial results concerning strength gains in eccentric, isometric and concentric tests. Therefore, the goal of this study was to evaluate torque-velocity adaptations following isokinetic eccentric training protocol using the quadriceps as a model. Twenty physically active men were randomly assigned to a control group (CG; n = 10) or to an eccentric training group (ETG; n = 10). Knee extensor torque-velocity relationship including isometric tests and isokinetic tests at 60 ◦ /s, 120 ◦ /s, 180 ◦ /s, 240 ◦ /s and 300 ◦ /s in concentric and eccentric modes, were assessed before and after a 12-week period of eccentric training (3 sessions/week; 2-5 sets of 7-9 maximal repetitions per session performed at 60 ◦ /s along a range of motion 90 ◦ ). Isokinetic eccentric training significantly increased the knee extensor torque at the training velocity (59%) and at the adjacent velocities (24% at 120 ◦ /s and 29% in the isometric test). These results demonstrate the specificity of strength gains

Effects of Tai Chi Chuan on the elderly balance: a semi-experimental study

Aging impairs the functional capacity, possibly compromising the balance over the years. However, Tai Chi Chuan is a martial art that can provide balance improvements in elderly people. This study aimed to evaluate balance in elderly after three and six months of Tai Chi Chuan practicing. Participants were 27 individuals (62±4.4 years) who underwent Tai Chi Chuan training (one hour each) twice a week, for six months. Balance was assessed by the Timed Up and Go (TUG) test, Berg Balance Scale (BBS) and Romberg test, all evaluated before and after three and six months of practicing. MANOVA for repeated measures was used to compare times in TUG and BBS tests. The Cochrane Q test was used to compare moments and frequencies in the Romberg test (α=0.05). Results showed significant improvement in TUG performance (p≤0.01), BBS score (p≤0.01) and in the Romberg test (p≤0.01) after three and six months, compared with pre-training. These results suggest that Tai Chi Chuan practice can improve the balance in elderly people.

Neural and morphological adaptations of vastus lateralis and vastus medialis muscles to isokinetic eccentric training

Abstract —Vastus lateralis (VL) and vastus medialis (VM) are frequently targeted in conditioning/rehabilitation programs due to their role in patellar stabilization during knee extension. This study assessed neural and muscular adaptations in these two muscles after an isokinetic eccentric training program. Twenty healthy men underwent a four-week control period followed by a 12-week period of isokinetic eccentric training. Ultrasound evaluations of VL and VM muscle thi -ckness at rest and electromyographic evaluations during maximal isometric tests were used to assess the morphological and neural properties, respectively. No morphological and neural changes were found throughout the control period, whereas both muscles showed significant increases in thickness (VL = 6.9%; p .05) post-training. Isokinetic eccentric training produces neural and greater morphological adaptations in VM compared to VL, which shows that synergistic muscles respond differently to an eccentric isokinetic strength training program.Keywords: knee extensors, isokinetic dynamometry, ultrasonography, electromyography

Influência do treinamento excêntrico nas razões de torque de flexores/extensores do joelho

Eccentric training produces skeletal muscle adaptations that help preventing muscle injuries, being often used in rehabilitation and physical fitness programs, but little is known of the effects of this training in the balance between knee antagonistic muscles. Torque ratios allow determining such balance. The purpose of this study was to assess the effect of a 12-week eccentric training program on the eccentric torque ratio between hamstring and quadriceps muscles (Hecc:Qecc). Twenty-four healthy male subjects were assigned to either a control group (CG, n=13, aged 27.7±4.6 years) or an experimental group (EG, n=11, aged 28.5±9.5 years). An isokinetic dinamometer was used (angular velocity -60o/s) for both the eccentric training and the assessments, performed every four weeks. Torque ratios measured were statistically compared between groups and intragroups between assessments, with (significance level set at p<0.05. In EG a reduction in torque ratios was found from the initial assessment (AS1) to the other three ones: AS1x AS2, p=0.005; AS1x AS3, p=0.001; and AS1x AS4, p<0.001. At the last evaluation, EG torque ratios were lower than those of CGs (p=0.041). Eccentric training hence changes balance between knee flexor and extensor muscles: a 12-week training program leads to lower Hecc:Qecc ratio and to extensor torque increase, with no significant change in flexor torque, being thus suitable for rehabilitation aimed at strengthening knee extensor muscles.

Time course of neuromechanical and morphological adaptations to triceps surae isokinetic eccentric training

OBJECTIVES To document the magnitude and the time course of neuromechanical and morphological adaptations in response to a triceps surae eccentric training program. METHODS Twenty healthy male subjects completed a control period followed by a 12-week isokinetic eccentric training program. Triceps surae neuromechanical and morphological evaluations were performed every 4 weeks. RESULTS The training program led to increases in: eccentric (32%), isometric (13%) and concentric (20%) torques; eccentric (32%) and isometric (24%) electromyographic activity; and, muscle thickness (14%). Torque and muscle thickness increased until the 8th training week. Eccentric and isometric activation increased until the 4th training week. No change was found in concentric activation. The angles of peak torque in eccentric and concentric tests shifted towards longer muscle lengths. While eccentric and isometric strength gains are explained by increased neural activation and muscle mass, changes in concentric torque are not related to neural effects. CONCLUSIONS Eccentric training led to increases in maximum eccentric and isometric force production due to adaptations in muscle activation and muscle mass. Among the advantages of the shift in the optimal length for force production towards longer lengths, are the increased total joint range of motion and a lower predisposition for muscle strain injuries.

Efeitos de oito semanas de treinamento com estimulação elétrica neuromuscular nas razões de ativação muscular / torque de idosas com osteoartrite

Introduction: Aging affects the musculoskeletal system, which can lead to osteoarthritis, causing degeneration of the articular cartilage and consequently resulting in functional impairment among elderly patients. However, neuromuscular electrical stimulation (NMES) training can be used as a mode of muscle strengthening.Objective: To investigate the effects of eight weeks of NMES training of the knee extensors on the RMS/torque ratio of elderly persons with osteoarthritis.Methods: Twenty-four elderly women were assigned into two groups: a healthy group (HE; n=12) and an osteoarthritis group (OA; n=12). The OA group was submitted to eight weeks of NMES training.Results: In the OA group, the RMS values increased from the pre-training to the post-training periods (p 0.05). Quadriceps torque was higher in the OA group in the post-training period at 90o of knee flexion (p 0.05).Conclusion: Eight weeks of NMES training resulted in a significant increase in the RMS and torque values of the quadriceps, but these neural adaptations were not sufficient to improve the osteoarthritis group to levels similar to the healthy group.

Changes in muscular activation patterns produced by a toning shoe during treadmill walking and quiet standing

Background: Recently a new shoe design with air compartments at the insole has been developed and termed as toning shoes. However, it is unclear how this air compartments-based shoe could affect muscle activation and centre of pressure during treadmill walking or quiet standing. Purpose: The aim of this study was to compare muscular activation during treadmill walking and quiet standing between toning shoes and regular shoes. Methods: Ten participants performed treadmill walking at 4.5 km.h−1 and unipodal standing wearing regular shoes and toning shoes in random order. Mean muscular activation of seven muscles from preferred lower limb (tibialis anterior, soleus, peroneus brevis, biceps femoris, gastrocnemius medialis, vastus lateralis, and rectus femoris) at different phases of the gait cycle (first half of contact, second half of contact and balance time) were assessed and compared between regular and toning shoes. Coefficient of variation and centre of pressure were calculated for temporal parameters and compared between regular and toning shoes. Principal results: Toning shoes led to higher coefficient of variation (20% during contact time; 15% during balance time), which may indicate a more unstable walking dynamic. Furthermore, the main muscular activation outcome was a 7% higher activation for rectus femoris and 7% lower activation for vastus lateralis at first half of contact time and higher activation for vastus lateralis (8%) and lower activation for rectus femoris (15%) at second half of contact time. Centre of pressure excursion and muscular activation during standing presented no significant differences. Conclusion: Toning shoe usage is increasing among the population and a better knowledge of effects on muscular activation and postural balance is fundamental. Toning shoes use resulted in a change in muscular activation during treadmill walking mainly for the quadriceps muscle. Some other muscle groups showed small differences in muscular activation patterns. There were no differences in postural balance and muscular activity during quiet standing with toning shoes use.