Quadriceps Muscle: Difference between revisions
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== Functional Coordination between the different Vasti == | == Functional Coordination between the different Vasti == | ||
The myoelectric balance of the quadriceps is essential for a correct movement of the patella. | The myoelectric balance of the quadriceps is essential for a correct movement of the [[patella]]. | ||
The proprioceptive afferents of the muscle contribute to maintaining adequate posture. Recent studies show that the activation of these afferents allows the contralateral quadriceps muscle to improve its coordination, increasing postural balance. The quadriceps allows an independent walk, helps with stair climbing, and enables sit to stand. | The proprioceptive afferents of the muscle contribute to maintaining adequate posture. Recent studies show that the activation of these afferents allows the contralateral quadriceps muscle to improve its coordination, increasing postural balance. The quadriceps allows an independent walk, helps with stair climbing, and enables sit to stand. | ||
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'''Aging''' | '''Aging''' | ||
The muscular adaptation of the quadriceps muscle with advancing age changes its morphology and function. | The muscular adaptation of the quadriceps muscle with [[Older People - An Introduction|advancing age]] changes its morphology and function. The musculature loses mass and volume (sarcopenia) decreases strength and [[Coordination Exercises|coordination]]. Motor units are lost (denervation processes), while the percentage of red fibers increases. This increases the fibrosis processes and the intramuscular fat. | ||
'''Chronic Obstructive Pulmonary Disease (COPD) and Chronic Heart Failure''' | '''[[COPD (Chronic Obstructive Pulmonary Disease)|Chronic Obstructive Pulmonary Disease]] (COPD) and [[Introduction to Congestive Heart Failure|Chronic Heart Failure]]''' | ||
The presence of chronic and ingravescent respiratory diseases such as COPD determines a decrease in muscle mass of the quadriceps femoris muscle, an increase of the connective tissue, and fibrosis phenomena. This leads to decreased contractile capacity, less strength, and less balance during walking or standing posture. The anaerobic fibers increase at the expense of the oxidative fibers; the muscles fatiguing more easily. An increase in intramuscular fat, with local and systemic metabolic alteration (increased cardiovascular risk) also occur. The females suffer more from the functional alteration of the muscle than the males. | The presence of chronic and ingravescent respiratory diseases such as COPD determines a decrease in muscle mass of the quadriceps femoris muscle, an increase of the connective tissue, and fibrosis phenomena. This leads to decreased contractile capacity, less strength, and less balance during walking or standing posture. The anaerobic fibers increase at the expense of the oxidative fibers; the muscles fatiguing more easily. An increase in intramuscular fat, with local and systemic metabolic alteration (increased cardiovascular risk) also occur. The females suffer more from the functional alteration of the muscle than the males. | ||
'''Multiple Sclerosis''' | '''[[Multiple Sclerosis]]''' | ||
In multiple sclerosis, the quadriceps muscle loses muscle mass and strength, with a decrease in oxidative fibers but with an increase in anaerobic fibers. Although there is an increase in the number of white fibers, the latter suffer more atrophy. Increase intramuscular fat and fibrosis processes.<ref name=":0" /> | In multiple sclerosis, the quadriceps muscle loses muscle mass and strength, with a decrease in oxidative fibers but with an increase in anaerobic fibers. Although there is an increase in the number of white fibers, the latter suffer more atrophy. Increase intramuscular fat and fibrosis processes.<ref name=":0" /> | ||
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<references /> | <references /> | ||
[[Category:Muscles]] | |||
[[Category:Sports Injuries]] | |||
[[Category:Anatomy]] | |||
Revision as of 08:18, 7 February 2020
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Introduction[edit | edit source]
The quadriceps femoris is the most voluminous muscle of the human body.[1]
The Quadriceps femoris is a hip flexor and a knee extensor. It is located in the anterior compartment of the thigh. This muscle is composed of 4 sub components:
- Rectus femoris
- Vastus lateralis
- Vastus medialis
- Vastus intermedius (see links for further elaboration)
The rectus femoris originates at the ilium, thus crossing both the hip and knee joint along its course. This anatomy allows for hip flexion and knee extension. The remaining muscles originate on the femur and function solely as knee extensors. Innervation of these muscles is by the femoral nerve. The quadriceps are primarily active in kicking, jumping, and running[2].
Clinical relevance[edit | edit source]
From a sporting point of view, it is an extraordinarily important muscle, but due to the stress it receives, it is often subject to trauma. Injury to the quadriceps muscle group can be painful and debilitating. Strains, tears and contusions of the quadriceps are common in athletics and result in lost time from training and competition.
The quadriceps is essential for daily activities, such as climbing stairs or getting up from the chair.
Myositis Ossificans-(MO) A complication associated with severe quadriceps contusions; this is a non-neoplastic proliferation of bone and cartilage in the area of contusion injury. In contusions, the reported incidence is between 9 and 17%. MO should be suspected if symptoms worsen after 2–3 weeks accompanied by loss of knee flexion and persistent swelling
Functional Coordination between the different Vasti[edit | edit source]
The myoelectric balance of the quadriceps is essential for a correct movement of the patella.
The proprioceptive afferents of the muscle contribute to maintaining adequate posture. Recent studies show that the activation of these afferents allows the contralateral quadriceps muscle to improve its coordination, increasing postural balance. The quadriceps allows an independent walk, helps with stair climbing, and enables sit to stand.
The rectus femoris can activate its fibers in the longitudinal mode. It can activate the proximal fibers in the absence of contraction of the most distal fibers. If the action of the quadriceps continues, it will activate the most distal fibers, in the absence of the most proximal ones (probably a mechanism to delay the onset of fatigue).
The patellar tendon insertion of the vastus medialis is small and is not able to generate a force capable of medially stabilizing the patella during knee extension. The force expressed by the vastus medialis during the extension is modest. In reality, during its contraction, it pulls the aponeurosis of the vastus intermedius, counteracting the lateral forces on the patella of the vastus lateralis. The vastus medialis acts indirectly as a patellar stabilizer, placing its contractile force on the median axis of the femur.
The strength expressed by the vastus lateralis increases with the increase in knee flexion. This mechanism is due to the length of the fibers compared to the connective structure of the muscle. Longer fibers express greater strength and make better use of the elasticity or resistance of the connective tissue. When the knee is extended, the vastus lateralis places a small force that is useful for maintaining the position with minimal effort.[1]
Adaptations of the Quadriceps Muscle in the Presence of Disease[edit | edit source]
Skeletal muscle adapts in the presence of systemic diseases. This means that the function of the muscle changes both metabolism and volumes, worsening the symptomatic picture eg
Aging
The muscular adaptation of the quadriceps muscle with advancing age changes its morphology and function. The musculature loses mass and volume (sarcopenia) decreases strength and coordination. Motor units are lost (denervation processes), while the percentage of red fibers increases. This increases the fibrosis processes and the intramuscular fat.
Chronic Obstructive Pulmonary Disease (COPD) and Chronic Heart Failure
The presence of chronic and ingravescent respiratory diseases such as COPD determines a decrease in muscle mass of the quadriceps femoris muscle, an increase of the connective tissue, and fibrosis phenomena. This leads to decreased contractile capacity, less strength, and less balance during walking or standing posture. The anaerobic fibers increase at the expense of the oxidative fibers; the muscles fatiguing more easily. An increase in intramuscular fat, with local and systemic metabolic alteration (increased cardiovascular risk) also occur. The females suffer more from the functional alteration of the muscle than the males.
In multiple sclerosis, the quadriceps muscle loses muscle mass and strength, with a decrease in oxidative fibers but with an increase in anaerobic fibers. Although there is an increase in the number of white fibers, the latter suffer more atrophy. Increase intramuscular fat and fibrosis processes.[1]
References[edit | edit source]
- ↑ 1.0 1.1 1.2 Bordoni B, Varacallo M. Anatomy, Bony Pelvis and Lower Limb, Thigh Quadriceps Muscle. InStatPearls [Internet] 2018 Dec 15. StatPearls Publishing.Available from:https://www.ncbi.nlm.nih.gov/books/NBK513334/ (last accessed 7.2.2020)
- ↑ Kary JM. Diagnosis and management of quadriceps strains and contusions. Current reviews in musculoskeletal medicine. 2010 Oct 1;3(1-4):26-31. Available from:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2941577/ (last accessed 7.2.2020)
