Search results for "Knee flexion"

Neural activation after maximal isometric contractions at different muscle lengths.

2006

DESBROSSES K., N. BABAULT, G. SCAGLIONI, J.-P. MEYER, and M. POUSSON. Neural Activation after Maximal Isometric Contractions at Different Muscle Lengths. Med. Sci. Sports Exerc., Vol. 38, No. 5, pp. 937–944, 2006. Purpose: To investigate i) whether neural activation dependence on muscle length is preserved with neuromuscular fatigue and ii) whether fatigue induced by a maximal isometric exercise is muscle length dependent. Methods: Twelve male subjects performed two fatiguing quadriceps muscle exercises: FS is the fatigue carried out at short muscle length (S) (S = 40- of knee flexion) and FL is the fatigue at long muscle length (L) (L = 100-). Before and after each fatiguing exercise (i.e.…

Superimposing hip extension on knee flexion evokes higher activation in biceps femoris than knee flexion alone.

2021

Hamstring muscle function during knee flexion has been linked to hamstring injury and performance. However, it is unclear whether knee flexion alone (KF) requires similar hamstring electromyography (EMG) activity pattern to simultaneous hip extension and knee flexion (HE-KF), a combination that occurs in the late swing phase of sprinting. This study examined whether HE-KF maximal voluntary isometric contraction (MVIC) evokes higher (EMG) activity in biceps femoris long head (BFlh) and semitendinosus (ST) than KF alone. Effects of shank rotation angles were also tested. Twenty-one males performed the above-mentioned MVICs while EMG activity was measured along ST and BFlh. Conditions were com…

Maximal voluntary isokinetic knee flexion torque is associated with femoral shaft bone strength indices in knee replacement patients.

2012

It is currently unknown whether knee replacement-associated bone loss is modified by rehabilitation programs. Thus, a sample of 45 (18 men and 25 women) persons with unilateral knee replacement were recruited; age 66 years (sd 6), height 169 cm (sd 8), body mass 83 kg (sd 15), time since operation 10 months (sd 4) to explore the associations between maximal torque/power in knee extension/flexion and femoral mid-shaft bone traits (Cortical cross-sectional area (CoA, mm(2)), cortical volumetric bone mineral density (CoD, mg/mm(3)) and bone bending strength index (SSI, mm(3))). Bone traits were calculated from a single computed tomography slice from the femoral mid-shaft. Pain in the operated …

Reliability of Y-Balance Test y Wight Bearing Lunge Test for the clinical-functional evolution of plantar fasciitis

2018

[Resumen] Objetivos: Los objetivos de nuestro estudio han sido determinar en pacientes con FP unilateral la fiabilidad intraobservador del instrumento Y- Balance Test (YBT) y la prueba Wight Bearing Lunge Test (WBLT) medida con el inclinómetro de un telefono movil inteligente. Métodos: Estudio transversal y observacional, realizado con 16 pacientes (9 mujeres y 7 hombres). Resultados: Los resultados obtenidos revelan una excelente fiabilidad relativa intraobservador. El YBT mostró un CCI de 0’946; mientras que las medidas con inclinómetro obtuvieron un CCI de 0’992. En el YBT se apreció una asociación de variables estadísticamente significativa en la dirección posteromedial (p=0’004) y en e…

Isokinetic Strength Profile In Serbian Female National Sambo Team

Factors related to excessive patellofemoral loading in rearfoot running

2015

Running is recognized as one of the most popular exercise methods. Furthermore, running related injuries have been under the scope for the last few decades. Synchronous function between the segments of the lower limbs is necessary for efficient locomotion. Patellofemoral pain syndrome is a common exercise related syndrome and multifactorial in nature. The purpose of this study was to measure contact forces and frontal plane moments to detect the factors that are associated with atypically high patellofemoral joint loading in rearfoot striking (RFS) running pattern, and moreover, which could possibly contribute to development of the patellofemoral pain syndrome. 39 team sport female athletes…

Sagittal Plane Hip, Knee, and Ankle Biomechanics and the Risk of Anterior Cruciate Ligament Injury: A Prospective Study

2018

Background: Stiff landings with less knee flexion and high vertical ground-reaction forces have been shown to be associated with an increased risk of anterior cruciate ligament (ACL) injury. The literature on the association between other sagittal plane measures and the risk of ACL injuries with a prospective study design is lacking. Purpose: To investigate the relationship between selected sagittal plane hip, knee, and ankle biomechanics and the risk of ACL injury in young female team-sport athletes. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 171 female basketball and floorball athletes (age range, 12-21 years) participated in a vertical drop jump test usin…

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 …

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 …

The impact of multilevel surgery on functional abilities and participation in adolescents with cerebral palsy (CP)

2013

but not significant decrease in RT group. Timing of pKFSw, range of knee flexion and knee flexion velocity improved after surgery but tended to deteriorate over the years in either group. Discussionandconclusions:The results of thepresent study for the first time suggest that the influences of proximal RF release on DRFT effects on the knee joint are negligible. Two possible explanations shouldbe considered. First, thefindingsmaybe explainedby a permanent eliminationofRF functionon thekneeafterDRFT,which would be unaffected by proximal release and would underline the efficiency of DRFT. Secondly, surgery in the proximal part does not influence the distal part. This would represent a new imp…