Search results for "hamstring"
showing 10 items of 57 documents
Focusing on Increasing Velocity during Heavy Resistance Knee Flexion Exercise Boosts Hamstring Muscle Activity in Chronic Stroke Patients
2016
Background. Muscle strength is markedly reduced in stroke patients, which has negative implications for functional capacity and work ability. Different types of feedback during strength training exercises may alter neuromuscular activity and functional gains.Objective. To compare levels of muscle activity during conditions of blindfolding and intended high contraction speed with a normal condition of high-intensity knee flexions.Methods. Eighteen patients performed unilateral machine knee flexions with a 10-repetition maximum load. Surface electromyography (EMG) was recorded from the quadrics and hamstring muscles and normalized to maximal EMG (nEMG) of the nonparetic limb.Results. For the …
Exercise for fitness does not decrease the muscular inactivity time during normal daily life
2012
The time spent in sedentary behaviors has been shown to be independent of exercise in epidemiological studies. We examined within an individual whether exercise alters the time of muscular inactivity within his/her normal daily life. Quadriceps and hamstring muscle electromyographic activities and heart rate were measured during 1 to 6 days of normal daily living of ordinary people. Of 84 volunteers measured, 27 (15 men, 12 women, 40.7 years ± 16.5 years) fulfilled the criteria of having at least 1 day with and 1 day without exercise for fitness (total of 87 days analyzed, 13.0 h ± 2.5 h/day). Reported exercises varied from Nordic walking to strength training and ball games lasting 30 min-1…
Validity of an inertial system for measuring velocity, force, and power during hamstring exercises performed on a flywheel resistance training device
2020
Background Inertial hamstring exercises promote functional changes leading to lower rates of hamstring injuries. However, variable training measurement systems have not been specifically validated for hamstring exercises. Accordingly, this study aimed to evaluate the validity of the Inertial Measurement System (IMS) to measure the velocity, force, and power during the performance of different hamstring exercises on a flywheel resistance training device. Methods Fifteen males (average age: 22.4 ± 2.5 years; body mass: 77.3 ± 9.8 kg; height: 179.5 ± 7.4 cm; weekly physical activity: 434.0 ± 169.2 min; years of strength training: 4.3 ± 2.2 years) performed the bilateral stiff-leg deadlift (SD…
Comparison of conventional hamstring/quadriceps ratio between genders in level-matched soccer players
2017
Abstract Objectives The main goal of our study is to compare the hamstring/quadriceps ( H / Q ) ratio at different knee angles between level-matched male and female soccer players and to determine whether differences in the H / Q ratio exist between the dominant and the non-dominant leg. Methods A cross-sectional study design was used to compare an isometric H / Q ratio and functional isokinetic ratio (between hamstring in eccentric contraction and quadriceps in concentric contraction) between males ( n = 14) and females ( n = 14). These ratios were studied at two different speeds of movement (60° s −1 and 180° s −1 ) and in five different positions (40°, 50°, 60°, 70° and 80° degrees of …
Do Running and Strength Exercises Reduce Daily Muscle Inactivity Time?
2016
Understanding how a specific exercise changes daily activity patterns is important when designing physical activity interventions. We examined the effects of strength and interval running exercise sessions on daily activity patterns using recordings of quadriceps and hamstring muscle electromyographic (EMG) activity and inactivity. Five male and five female subjects taking part in a 10-week training programme containing both strength and interval running training sessions were measured for daily muscle EMG activities during three days: on a strength day, an interval running day, and a day without exercise. EMG was measured using textile electrodes embedded into sport shorts that were worn 9…
Validity, Reliability, and Sensitivity to Change of DiCI for the Strength Measurement of Knee and Hip Muscles
2020
Many professionals use the handheld dynamometers (HHDs) to assess isometric strength. This study aimed to evaluate the validity, reliability, and sensitivity to change of a DiCI (a new HHD) for the...
Activation and torque deficits in ACL-reconstructed patients 4 months post-operative
2001
This study compares knee extension and flexion torques and electromyographic (EMG) activity of normal and anterior cruciate ligament (ACL)-reconstructed knees during maximal unilateral isometric and isokinetic tests performed 4–5 months after ACL reconstruction. The subjects consisted of 3 age- and activity-matched groups of 6 subjects: a healthy control group (Ctrl) and 2 groups of patients, with Kenneth-Jones technique using autologous patellar-ligament graft (KJ group) and autologous graft from the semitendinosus tendon (ST group). When compared to the Ctrl group values, each patient group had significant bilateral extension torque deficits in isometric and at slow velocity concentric co…
REGIONAL DIFFERENCES IN BICEPS FEMORIS FASCICLE LENGTH AND PENNATION ANGLE AFTER A SIMULATED SOCCER MATCH
2017
Background Hamstring Strain Injuries (HSIs) represent 12% of all injuries in soccer players, and their incidence has increased in recent years. Between 53%-84% of HSIs involve the Biceps femoris muscle (BF). Recent studies have shown that soccer players with shorter BF fascicle length (FL) suffer more HSIs and exhibit regional differences in FL and pennation angle (PA) along BF. It is unclear whether there is any regional difference in the degree of change of these parameters after a soccer match. Objective Describe changes in BF muscle architecture after a simulated soccer match. Design Controlled laboratory study. Pre and Post single session. Setting Laboratory. Amateur Level. Participant…
AB0929 Balance in fibromyalgia is not related with lower limb strength
2017
Background Postural control, that depends on many sensory contributors and motor skills, is altered in people with fibromyalgia (FM) 1–3. Knowing those contributors that could be impaired in this population is important to design an appropriate balance therapy. Objectives Due to the fact that people with FM use to present a strength loss 7, our main goal was to explore the relation between postural control and lower limb strength in this population. Further, the sensory inputs contributors to the postural control were assessed. Methods A cross-sectional study was conducted in a sample of 40 FM patients. A force platform was used to assess postural control under five bipedal conditions: i) e…
Children’s physical activity and sedentary time compared using assessments of accelerometry counts and muscle activity level
2018
Background This research compared accelerometry (ACC)-derived and muscle electromyography (EMG)-based estimates of physical activity (PA) and sedentary time in typical PA tasks and during the daily lives of children. Methods Data was included from two exploratory studies. In Study I, 6–7-year-old children (n = 11, 64% girls) were assessed for eight PA tasks (walking, stair negotiation, climbing, crawling, swinging, balancing, trampoline jumping and a game of tag). In Study II, 7–9-year-old children (n = 14, 38% girls) were assessed for six PA tasks (walking, sitting, static squat, single leg hops, jump for height and standing long jump), and daily PA during one day with and one day without…