André Luiz Félix Rodacki

Peak torque and rate of torque development in elderly with and without fall history

BACKGROUNDnFalls are one of the greatest concerns among the elderly. A number of studies have described peak torque as one of the best fall-related predictor. No studies have comprehensively focused on the rate of torque development of the lower limb muscles among elderly fallers. Then, the aim of this study was to determine the relationship between muscle peak torque and rate of torque development of the lower limb joints in elderly with and without fall history. It was also aimed to determine whether these parameters of muscle performance (i.e., peak torque and rate of torque development) are related to the number of falls.nnnMETHODSnThirty-one women volunteered to participate in the study and were assigned in one of the groups according to the number of falls over the 12 months that preceded the present. Then, participants with no fall history (GI; n=13; 67.6[7.5] years-old), one fall (GII; n=8; 66.0[4.9] years-old) and two or more falls (GIII; n=10; 67.8[8.8] years-old) performed a number of lower limb maximal isometric voluntary contractions from which peak torque and rate of torque development were quantified.nnnFINDINGSnPrimary outcomes indicated no peak torque differences between experimental groups in any lower limb joint. The rate of torque development of the knee flexor muscles observed in the non-fallers (GI) was greater than that observed in the fallers (P<0.05) and had a significant relationship with the number of falls (P<0.05).nnnINTERPRETATIONnThe greater knee flexor muscles rate of torque development found in the non-fallers in comparison to the fallers indicated that the ability of the elderly to rapidly reorganise the arrangement of the lower limb may play a significant role in allowing the elderly to recover balance after a trip. Thus, training stimulus aimed to improve the rate of torque development may be more beneficial to prevent falls among the elderly than other training stimulus, which are not specifically designed to improve the ability to rapidly produce large amounts of torque.

Strength training improves fall-related gait kinematics in the elderly: A randomized controlled trial

BACKGROUNDnFalls are one of the greatest concerns among the elderly. Among a number of strategies proposed to reduce the risk of falls, improving muscle strength has been applied as a successful preventive strategy. Although it has been suggested as a relevant strategy, no studies have analyzed how muscle strength improvements affect the gait pattern. The aim of this study was to determine the effects of a lower limb strength training program on gait kinematics parameters associated with the risk of falls in elderly women.nnnMETHODSnTwenty seven elderly women were assigned in a balance and randomized order into an experimental (n=14; age=61.1 (4.3)years, BMI=26.4 (2.8)kgm(-2)) and a control (n=13; age=61.6 (6.6)years; BMI=25.9 (3.0)kgm(-2)) group. The EG performed lower limb strength training during 12 weeks (3 days per week), being training load increased weekly.nnnFINDINGSnPrimary outcomes were gait kinematics parameters and maximum voluntary isometric contractions at pre- and post-training period. Secondary outcomes were training load improvement weekly and one repetition maximum every two weeks. The 1 maximal repetition increment ranged from 32% to 97% and was the best predictor of changes in gait parameters (spatial, temporal and angular variables) after training for the experimental group. Z-score analysis revealed that the strength training was effective in reversing age-related changes in gait speed, stride length, cadence and toe clearance, approaching the elderly to reference values for healthy young women.nnnINTERPRETATIONnLower limb strength training improves fall-related gait kinematic parameters. Thus, strength training programs should be recommended to the elderly women in order to change their gait pattern towards young adults.

Influence of training background on jumping height.

The aim of this study was to compare the pattern of force production and center of mass kinematics in maximal vertical jump performance between power athletes, recreational bodybuilders, and physically active subjects. Twenty-seven healthy male subjects (age: 24.5 ± 4.3 years, height: 178.7 ± 15.2 cm, and weight: 81.9 ± 12.7 kg) with distinct training backgrounds were divided into 3 groups: power track athletes (PT, n = 10) with international experience, recreational bodybuilders (BB, n = 7) with at least 2 years of training experience, and physically active subjects (PA, n = 10). Subjects performed a 1 repetition maximum (1RM) leg press test and 5 countermovement jumps with no instructions regarding jumping technique. The power-trained group jumped significantly higher (p > 0.05) than the BB and PA groups (0.40 ± 0.05, 0.31 ± 0.04, and 0.30 ± 0.05, respectively). The difference in jumping height was not produced by higher rates of force development (RFD) and shorter center of mass (CM) displacement. Instead, the PT group had greater CM excursion (p > 0.05) than the other groups. The PT and BB groups had a high correlation between jumping height and 1RM test (r = 0.93 and r = 0.89, p > 0.05, respectively). In conclusion, maximum strength seems to be important for jumping height, but RFD does not seem relevant to achieve maximum jumping heights. High RFD jumps should be performed during training only when sport skills have a time constraint for force application.

Functional capacity, muscle strength and falls in women with fibromyalgia ☆

BACKGROUNDnPatients with fibromyalgia have difficulty with activities of daily living, they exhibit reduced muscle strength and high incidence of reported falls. The objective of this study was to evaluate the functional performance and lower limb muscle strength in women with fibromyalgia and determine the relationship between muscle strength and falls.nnnMETHODSnSixteen females with fibromyalgia and 16 healthy women participated in the study. Pain intensity, fibromyalgia impact on quality of life, physical activity level and fall prevalence were assessed. The peak torque and the rate of torque development were determined in maximal voluntary isometric contraction (hip, knee and ankle joints) using a load cell. The 30s chair stand, 8 ft up and go, sit and reach, and functional reach tests were used to characterize functional performance.nnnFINDINGSnWomen with fibromyalgia showed deficits in lower limb muscle strength, balance and agility and exhibited decreased knee extension peak torque and rate of torque development. In addition, they showed lower hip adduction and extension peak torque in comparison to the control group (P>0.05). Hip extension rate of torque development, duration of fibromyalgia symptoms, overall pain, knee pain, and fibromyalgia impact were strong predictors of the number of falls in patients with fibromyalgia (R2=0.86; P<0.05), when considered collectively.nnnINTERPRETATIONnWomen with fibromyalgia showed reduced functional performance and lower limb muscle strength, mostly explained by pain. There was a high prevalence of falls in this population, as explained by hip extensors rate of torque development, duration of fibromyalgia symptoms and pain.

Effects of physical exercise and nutritional guidance on metabolic syndrome in obese adolescents

OBJETIVOS: Analisar os efeitos de exercicios fisicos (EF) e orientacao nutricional (ON) sobre a composicao corporal, aptidao fisica, perfil lipidico e resistencia insulinica em adolescentes obesos com e sem sindrome metabolica (SM). METODOS: 64 obesos (26 meninos), com idade entre 10 a 16 anos, divididos em dois grupos: com SM (n=29) e sem SM (n=35). Utilizou-se como criterio de classificacao de SM a presenca de tres ou mais criterios para idade e sexo de acordo com Adult Treatment Panel III (ATP III). Mensuraram-se antes e apos 12 semanas de intervencao: pressao arterial, circunferencia abdominal, consumo maximo de oxigenio (VO2pico), glicemia, insulinemia, Homeostatic Metabolic Assessments (HOMA-IR), Quantitative Insulin Sensitivity Check Index (QUICKI) e perfil lipidico. Os dois grupos participaram de 12 semanas de EF e duas sessoes de ON. Cada sessao de EF consistiu em 50 minutos de ciclismo indoor, 50 minutos de caminhada e 20 minutos de alongamento, tres vezes por semana. RESULTADOS: 55 sujeitos (com SM=25; sem SM=30) completaram o tratamento. Apos 12 semanas, houve diminuicao na massa corporal, IMC escore-z, circunferencia abdominal, massa gorda, TG e aumento na estatura, HDL-C e VO2pico, em ambos os grupos. Alem disso, houve uma reducao na pressao arterial sistolica, aumento na sensibilidade a insulina (p<0,05) no grupo com SM. Os fatores de risco para SM diminuiram em 72%. CONCLUSAO: Apos a intervencao multidisciplinar, houve uma reducao nos fatores de risco, melhorando a aptidao fisica e perfil metabolico. A intervencao multidisciplinar foi efetiva para reducao da SM.

Transient effects of stretching exercises on gait parameters of elderly women

This study aimed to analyse the effects of a single stretching exercise session on a number of gait parameters in elderly participants in an attempt to determine whether these exercises can influence the risk of fall. Fifteen healthy women living in the community volunteered to participate in the study. A kinematic gait analysis was performed immediately before and after a session of static stretching exercises applied on hip flexor/extensor muscles. Results showed a significant influence of stretching exercises on a number of gait parameters, which have previously been proposed as fall predictors. Participants showed increased gait velocity, greater step length and reduced double support time during stance after performing stretching exercises, suggesting improved stability and mobility. Changes around the pelvis (increased anterior-posterior tilt and rotation range of motion) resulting from the stretching exercises were suggested to influence the gait parameters (velocity, step length and double support time). Therefore, stretching exercises were shown to be a promising strategy to facilitate changes in gait parameters related to the risk of fall. Some other gait variables related to the risk of fall remained unaltered (e.g., toe clearance). The stable pattern of segmental angular velocities was proposed to explain the stability of these unchanged gait variables. The results indicate that stretching exercises, performed on a regular (daily) basis, result in gait adaptations which can be considered as indicative of reduced fall risk. Other studies to determine whether regular stretching routines are an effective strategy to reduce the risk of fall are required.

Stretching Exercise Program Improves Gait in the Elderly

Background: Ageing is characterized by a number of physical changes that contribute to a decline in the ability to perform daily tasks. Stretching has been proposed to reduce hip flexion contracture and increase hip and pelvis range of motion, thus improving gait performance. Objective: The purpose of this study was to determine whether a supervised stretching program designed to improve the range of motion of the lower limbs alters gait kinematics in older adults. Methods: Twenty healthy older adult women (65.9 ± 4.2 years old and BMI 24.9 ± 3.5) were divided into 2 groups. The experimental group undertook 12 sessions of stretching exercises, whereas the control group did not engage in any physical activity. Gait performance was assessed at the beginning of the experiment and after the 4-week intervention period. Results: Those in the experimental group showed increased step length, higher velocity and reduced double support time after training. In addition, participants involved in the stretching program showed greater anterior and lateral pelvis tilt and also greater rotation (p < 0.05). Conclusions: Based on our results, we can suggest that a supervised stretching program is effective to alter a number of gait variables. Moreover, after the stretching protocol, aged participants displayed gait parameters which were similar to those reported in young healthy adults. Therefore, stretching can be used as an effective means to improve range of motion and reverse some age-related changes that influence gait performance.

Efeito transiente de exercícios de flexibilidade na articulação do quadril sobre a marcha de idosas

Gait is the most common activity performed by humans, being a fundamental motor ability to locomotion. However, ageing is characterized by a gradual reduction of the locomotor apparatus efficiency which occurs by the decrease in strength, muscle mass and flexibility. This study aimed to verify the transient effect of a single session of hip extensor and flexor muscles stretching exercises over gait in elderly subjects. Five elderly ladies (67.0 ± 3.8 years 1.59 ± 0.07 m; 64.3 ± 15.3 Kg) volunteered to participate in the study. Gait analysis was performed before and after stretching exercises. The stretching protocol was applied in a single session and consisted of three static stretching exercises conducted during 30s for the hip joint flexor and extensor muscles. After the stretching session, participants gait showed reduced pelvic anterior tilt peak, greater hip range of motion and extension peak, greater knee range of motion, greater knee peak flexion angle during the mid swing and greater toe clearance (28.6%). Results showed that immediately after a stretching session, the elderly women presented alterations in the gait pattern in which some variables suggest a reduced risk of fall. The effects of ageing over some variables were partially reversed and the participants presented a gait pattern more similar to young adults than before stretching.

Reliability and validity of the 30-s continuous jump test for anaerobic fitness evaluation

OBJECTIVESnTo determine the test-retest reliability and concurrent validity of the 30-s continuous jump (CJ30) test using the Wingate test as a reference.nnnDESIGNnDescriptive validity study.nnnMETHODSnTwenty-one male volleyball players (23.8 ± 3.8 years; 82.5 ± 9.1 kg; 185 ± 4.7 cm) were tested in three separate sessions. The first and second sessions were used to assess the reliability of the CJ30 while in the third session the Wingate test was performed. In the continuous jump test, consisting of maximal continuous jumps performed for 30s, jump height was determined by video kinematic analysis. Blood samples were collected after each test to determine lactate concentration.nnnRESULTSnThe CJ30 showed excellent test-retest reliability for the maximal jump height (ICC = 0.94), mean vertical jump height (ICC = 0.98) and fatigue index (ICC = 0.87). Peak lactate showed moderate reliability (ICC = 0.45). Large correlations were found between the mean height of the first four jumps of CJ30 and the peak power of the Wingate (r = 0.57), between the mean vertical jump height of CJ30 and the mean power of the Wingate (r = 0.70) and between the lactate peak of CJ30 and Wingate (r = 0.51). A moderate correlation of fatigue index between CJ30 and the Wingate was found (r = 0.43).nnnCONCLUSIONSnThe continuous jump is a reliable test and measures some of the same anaerobic properties as WAnT. The correlations observed in terms of anaerobic indices between the tests provide evidence that the CJ30 may adequately assess anaerobic performance level.

Balance, gait, functionality and strength: comparison between elderly fallers and non-fallers

BACKGROUND: Accidental falls are a major health problem related to aging and affect one in every three elderly individuals over the age of sixty. OBJECTIVE: To evaluate and compare the muscle strength, gait kinematics parameters, and performance in functional tests between elderly subjects with and without a prior history of falls. In addition, the association between the history of falls and the variables that demonstrated differences between groups were tested. METHOD: 62 elderly subjects participated in the study and were allocated to the group with falls history (FG; n=20; 68.0±6.9 years old) or the group without falls history (CG; n=42; 65.5±4.1 years old). Maximal strength, gait kinematics parameters, and functional tests were tested. RESULTS: The FG showed lower muscle strength in the knee flexors (51.45±8.6 vs. 62.09±19 Kg), lower average toe clearance during the swing phase (0.04±0.006 vs. 0.043 ± 0.005 m), and lower performance in the 8-foot up-and-go test (5.3±0.7 vs. 5.8±0.7 s) (p<0.05). There were no associations between any variables and falls, but the increased time in the 8-foot up-and-go test may double the likelihood of a fall occurring. CONCLUSION: Fallers have reduced lower limb strength, gait alterations, the worst performance in the dynamic balance test, and an increased risk of falls.