Muscles Flashcards
Hip flexors
• Rectus femoris (from iliac spine) • Psoas • Iliacus • Sartorius – longest muscle
What do hip flexors do?
• 1 – core stability - Key muscles in stabilising the pelvis and spine • 2 – hip flexion – pick up your leg or move chest to leg (when the angle between your trunk and leg decrease) • let you to walk, kick, bend, and swivel your hips. • under constant tension because of ergonomics and habitual postural positioning, often tight and shortened
Quadriceps
• Rectus femoris (from iliac spine) • Vastas medialis (inner) • Vastas intermedialis (middle) • Vastas lateralus (outer)
What do quadriceps do?
• Muscles that extend (straighten) the leg at the knee • Crucial for walking, running, jumping, getting up from a chair etc. • Antagonists to the hamstrings and glutes
Hamstrings
• Bicep femoris longhead (origin – ischial; insertion – fibula) • Bicep femoris shorthead (origin – femur; insertion – fibula) • Semimembranosus (origin – ischial; insertion – tibia) • Semitendinosus (origin – ischial; insertion – tibia)
What do hamstrings do?
• Hip and knee movements in walking, squatting, bending, tilting your pelvis • flex/bend your knee and extend your hip • Antagonist to the quadriceps – when contracted stretches the quads
external rotators
• External rotators x 10 • Gluteus maximus • Gluteus minimus • Gluteus medius • ITB and TFL • PGOGOQ (Quadratus Femoris)
what are external rotators of the hip
• Rotate and abduct (move away from the midline) the hip and leg away from the body • Piriformis helps with internal rotation
adductors
Pectineus Adductor brevis Adductor magnus Adductor longus Gricilis
What do adductors do?
- Adduct (move toward the midline/another part of the body), flexes, internally rotates hip - Groin/inner thigh muscles - responsible for pulling the legs toward each other, support balance and alignment - Antagonists – glutes
What are the layers of the abs?
- hold the abdominal organs in place, support the trunk and allow movement - Predominantly assists with flexion - Deepest layer = transverse abdominis - Internal oblique - External oblique - Rectus abdominis - serratus anterior
What are the pecs?
- Pectoralis major o bulk of the chest muscles and lies under the breast o They turn on and pull us forward. o Used in chataranga dandasana - Pectoralis minor o Beneath the pectoralis major is the pectoralis minor, a thin, triangular muscle.
Internal obliques - what do they do?
- sits low down on the side of the torso body - flex the trunk and compress its contents - rotates trunk to the same side as contracting muscle - side bending muscle to the same side as contracting muscle - have a protective as well as a supportive role, holding the abdominal organs in place
What muscles are used to bend/flex your knee?
hamstring
What happens if you contract your bicep?
do a bicep curl
What happens if you contract your tricep?
arm lengthens
Transverse abdominis - what does it do?
- deepest layer - acts as a stabilizer for the entire low back and core muscles - muscles create a deep natural “corset” around the internal organs and lumbar spine - weakness is often one of the many reasons people may experience low back pain
External obliques - what do they do?
- Flexes the trunk and compress contents - rotates trunk to the opposite side as contracting muscle - side bending muscle to the same side as contracting muscle
Transverse abdominis - what does it do?
- deepest layer - acts as a stabilizer for the entire low back and core muscles - muscles create a deep natural “corset” around the internal organs and lumbar spine - weakness is often one of the many reasons people may experience low back pain
Rectus abdominis - what does it do?
o sternum to pubic bone o the ab that is visible in people with low body fat o rounds spine forward and compresses the abdominals o stabilizes and controls tilt of the pelvis o outer muscle o Creates the airbag effect
serratus anterior - what does it do?
o originates on the surface of the 1st to 8th ribs at the side of the chest and inserts along the entire anterior length of the medial border of the scapula o pulls scapula forward o helps with upward rotation of the scapula
What do the back muscles do?
• Extension. Keeps us upright.
What is the deepest layer of the back?
- multifidus group
What do the multifidus muscles do?
o either side of vertebral column, spanning between the transverse and spinous processes of certain cervical, thoracic and lumbar vertebrae
o hold the spine up and rotation
o when they contract, they are connected in a way that twist you in the opposite direction
Erector Spinae muscles
- three muscles: the Iliocostalis, Longissimus, and Spinalis.
- parallel to the spine, the erectors span from the base of the skull to the pelvis.
- primary function is to hold us upright
- straighten the back and provide for side-to-side rotation
- Forward fold stretches these out
Quadratus lumborum
o back of the abdominal wall
o very important for stabilization of both vertebral column and the rib during various movements of the spine
o extends the lumbar spine, when activated on one side the trunk is bent towards that direction
Latissimus dorsi
o covers lower part of the back, extending from the sacral, lumbar, and lower thoracic vertebrae to the armpits o internally rotates and adducts the arm at the shoulder o extends the arm at the shoulder
Trapezius
o lies just beneath the skin and covering the upper back of the shoulders and neck o upright posture support o used to tilt and turn the head and neck, shrug, steady the shoulders, and twist the arms o trapezius elevates, depresses, rotates, and retracts the scapula, or shoulder blade
Rhomboids
o Rhomboid - Major and minor o pull the shoulder blades together o rotate the scapula in a downward direction and provide stability for your shoulders o Use them when cactus the arms o Garudasana stretches them
Serratus posterior
o Superior – lies underneath the rhomboids and trapezius, superficial to the top of the thoracic
o Inferior – superficial to the erector spinae muscles and deep to the latissimus dorsi muscle, bottom of thoracic spine
o Intermediate layer of muscles
o role in respiration superior elevates the ribs supports inhaling and inferior supports exhaling by depressing the ribs
What is an antagonistic pair?
A pair of muscles that when one contracts the other stretches
What does an agonist muscle do?
Contracts/produces movement
What does an antagonist muscle do?
Stretches, acting against or in opposition to the agonist muscle
How are muscles and the nervous system related?
The movement of muscles is coordinated and controlled by the nervous system, that sends a message to the muscles ‘telling’ it to move
What are the two types of isotonic muscle contractions?
Concentric Eccentric
What is an isometric muscle contraction?
Muscle generates force without changing length ie. holding a pose
What is an isotonic muscle contraction?
Tension remains unchanged but the muscle length changes ie. Moving into a pose
What is a concentric muscle contraction?
Muscle contracts to meet resistance, whilst shortening ie. bicep curl
What is an eccentric muscle contraction?
Muscle contracts whilst lengthening ie. Putting shopping down
What is reciprocal inhibition?
- the fundamental mechanism of how our bodies maintain posture and produce movement is by balancing continually contracting and relaxing opposing muscles
- when the agonist contracts, its antagonist relaxes
Stretch reflex – myotactic reflex
- when a muscles is lengthened during stretching, an impulse is sent to the spinal cord and a response to contract the muscle is received
- designed as a protective measure. It means that there will be an initial reflex action but that it will release after approximately 10 seconds and lengthen further
Agonist v antagonist
- Muscles that work like this are called antagonistic pairs.
- In an antagonistic muscle pair as one muscle contracts the other muscle relaxes or lengthens.
- The muscle that is contracting is called the agonist and the muscle that is relaxing or lengthening is called the antagonist.
Synergist
The synergist in a movement is the muscle(s) that stabilises a joint around which movement is occurring, which in turn helps the agonist function effectively. Synergist muscles also help to create the movement.
Co-contraction
Creating a bandha around the joint where co-contracting muscles, hugging into the midline
