Relationship between wire EMG activity, muscle length, and torque of the hamstrings

Mohamed, Olfat; Perry, Jacquelin; Hislop, Helen J.

doi:10.1016/s0268-0033(02)00070-0

Cited by 118 publications

(154 citation statements)

References 34 publications

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“…This increase in force production has been demonstrated in muscles of healthy subjects, in general, and in healthy hamstring muscles, in particular 4,5 . Weakness dependent on joint position in subjects with hemiparesis was largely described for upper extremity 3,6 .…”

Section: Introductionmentioning

confidence: 60%

Strength deficit of knee flexors is dependent on hip position in adults with chronic hemiparesis

Michaelsen¹,

Ovando²,

Bortolotti³

et al. 2013

Braz. J. Phys. Ther.

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| Background: The extent to which muscle length affects force production in paretic lower limb muscles after stroke in comparison to controls has not been established. Objectives: To investigate knee flexor strength deficits dependent on hip joint position in adults with hemiparesis and compare with healthy controls. Method: a cross-sectional study with ten subjects with chronic (63±40 months) hemiparesis with mild to moderate lower limb paresis (Fugl-Meyer score 26±3) and 10 neurologically healthy controls. Isometric knee flexion strength with the hip positioned at 90° and 0° of flexion was assessed randomly on the paretic and non-paretic side of hemiparetic subjects and healthy controls. Subjects were asked to perform a maximal isometric contraction sustained for four seconds and measured by a dynamometer. The ratio of knee flexor strength between these two hip positions was calculated: Hip 0°/Hip 90°. Also, locomotor capacity was evaluated by the timed up and go test and by walking velocity over 10 meters. Results: In subjects with hemiparesis, absolute knee flexion torque decreased (p<0.001) with the hip in extension (at 0°). The ratio of knee flexor torque Hip 0°/Hip 90° on the paretic side in hemiparetics was lower than in controls (p=0.02). Conclusions: Weakness dependent on joint position is more significant in the paretic lower limb of adults with hemiparesis when compared to controls. More attention should be given to lower limb muscle strengthening exercises in individuals with stroke, with emphasis on the strengthening exercises in positions in which the muscle is shortened.Keywords: stroke; lower extremity; muscle weakness; physical therapy; rehabilitation. HOW TO CITE THIS ARTICLEMichaelsen SM, Ovando AC, Bortolotti A, Bandini B. Strength deficit of knee flexors is dependent on hip position in adults with chronic hemiparesis. Braz J Phys Ther. 2013 Jan-Feb; 17(1):86-91. http://dx

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Section: Introductionmentioning

confidence: 60%

Strength deficit of knee flexors is dependent on hip position in adults with chronic hemiparesis

Michaelsen¹,

Ovando²,

Bortolotti³

et al. 2013

Braz. J. Phys. Ther.

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“…For instance, they investigated the effects of EO exercise during bench press and although no differences in neuromuscular activation were found for pectoralis major and triceps brachii greater activation during ECC action overload was observed for the anterior deltoid muscle in the same study. Different methodology was used compared to the present study, but possible differences could be related to the multi-joint exercise bench press characteristics which may allow different neural strategies than the uniarticular exercise 26 . Also the function of the different muscles (i.e.…”

Section: Discussionmentioning

confidence: 99%

“…Owing to the high synergistic action of the GM muscle and the 40% increase in the mechanical load, a difference between the protocols during the ECC action was expected. This lack of difference could be due to synergistic muscles may contribute to a different magnitude 26 . Previously, sartorius and gracilis muscles neuromuscular activation was analysed during knee flexion, and greater activation of the gracilis than the sartorius was found 26 .…”

Section: Discussionmentioning

confidence: 99%

“…This lack of difference could be due to synergistic muscles may contribute to a different magnitude 26 . Previously, sartorius and gracilis muscles neuromuscular activation was analysed during knee flexion, and greater activation of the gracilis than the sartorius was found 26 . There is little information in the literature regarding the level of contribution of each synergist muscle during the knee flexion, hindering the understanding of the impact of an EO protocol.…”

Section: Discussionmentioning

confidence: 99%

“…As a limitation, this study only analysed BF and GM muscles and as previously reported various muscles can exert a synergistic action during knee flexion along with the agonist muscles [26][27][28] . Additionally, the manual alteration of the mechanical device during the EO protocol must be considered.…”

Section: Discussionmentioning

confidence: 99%

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Acute neuromuscular response during eccentric overload protocol by using a mechanical device to increase the load

Lanza

Pertence

Andrade

et al. 2017

Rev. Bras. Cineantropom. Desempenho Hum.

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-The aim of this study was to propose a mechanical device that could increase the mechanical load during the entire eccentric (ECC) action on a knee flexor machine and to compare the muscular activity when the device was used during a testing protocol. Fifteen physically active women were recruited, and they performed two protocols: control and eccentric overload. Control protocol was performed with concentric (CON) and ECC actions with similar load (60% of one repetition maximum) whilst eccentric overload protocol consisted of ECC actions with 40% more load than CON actions. Muscular activation was measured using surface electromyography of the biceps femoris (BF) and the gastrocnemius medialis (GM) muscles. ECC actions presented a higher muscular activation during eccentric overload protocol than control protocol for BF (p = 0.032), but not for the GM (p = 0.439). The mechanical device increased the mechanical load during the ECC muscle action and consequently increased the amplitude of the neural drive to the BF muscle; however, it did not increase the amplitude of the neural drive to the GM muscle.Key words: Electromyography; Muscle contraction; Resistance training. Resumo -O objetivo deste estudo foi propor um dispositivo mecânico que acoplado a uma cadeira flexora aumente a carga mecânica durante toda a ação excêntrica (ECC) e comparar a atividade muscular durante a utilização do dispositivo proposto. Quinze mulheres fisicamente ativas foram recrutadas e realizaram dois diferentes protocolos (controle e sobrecarga ECC). O protocolo controle foi realizado com ações concêntricas (CON) e ECC com carga iguais (60% de uma repetição máxima), enquanto o protocolo de sobrecarga ECC consistiu em ações ECC com 40% mais de carga do que as ações CON. A ativação muscular dos músculos biceps femoris (BF) e gastrocnemius medialis (GM

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In vivo examination of the morphology of the tendinous inscription of the human semitendinosus muscle: Gender and joint position effects

Kellis

Balidou

2013

Journal of Morphology

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A tendinous inscription divides the semitendinosus muscle in two parts and it may have an effect on its function. The purpose of this study was to determine the effects of joint position and gender on the tendinous inscription morphology. Ultrasonography scans were taken from 76 young males and females at rest, in nine combinations of hip and knee joint angles. The length of the tendinous inscription arms and the angles formed by the two arms (apex angle), the tendinous inscription with the superficial (surface angle), and deep (deep angle) aponeurosis were determined. The tendinous inscription was clearly visible in 70 (out of 76) subjects. Analysis of variance designs showed that increasing hip flexion angle from 0 to 90° increased the long arm and muscle thickness but decreased the short tendinous inscription arm (P < 0.05). Changing knee flexion angle from 0 to 90° was accompanied by a longer tendinous inscription arm and an increased apex angle (P < 0.05). Long arm length and muscle thickness significantly increased from the shortest (hip 0° - knee 90°) to the longest muscle lengths (hip 0° - knee 90°). Males had a significantly higher surface, apex, and deep angle and a lower normalized tendinous inscription long arm than females (P < 0.05). These results indicate that the effect of the tendinous inscription (if any) on semitendinous muscle function depends on hip and knee joint angle while it may be gender dependent.

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Relationship between wire EMG activity, muscle length, and torque of the hamstrings

Cited by 118 publications

References 34 publications

Strength deficit of knee flexors is dependent on hip position in adults with chronic hemiparesis

Strength deficit of knee flexors is dependent on hip position in adults with chronic hemiparesis

Acute neuromuscular response during eccentric overload protocol by using a mechanical device to increase the load

In vivo examination of the morphology of the tendinous inscription of the human semitendinosus muscle: Gender and joint position effects

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