Muscle Origins, Insertions and Actions Flashcards
(49 cards)
1
Q
Gracilis (hip adductors)
A
- most vertical, slender and superficial of hip adductors
- only adductor to cross the knee and insert on to tibia = produces movement in both these joints
- origin: ischiopubic ramis
- insertion: medial surface of the tibia
- action: adduction of the hip and flexion of the knee
2
Q
pectineus (hip adductors)
A
- most anterior of hip adductor muscles
- anterior location enables it to assist the hip flexors
- origin: anterior surface of the pubis
- insertion: upper surface of the femur
- action: adduction and flexion of the hip
3
Q
tenor fascia latae (hip abductors)
A
- small muscle with very long tendon called IT band
- it also assists in hip flexion and knee extension
- only abductor to cross both hip and knee
- origin: anterior surface of the iliac crest
- insertion: lateral surface of the tibia via the iliotibial band
- action: flexion and abduction of the hip. when the hip in flexion, this muscle can also medially rotate the hip joint
4
Q
gluteus medius (hip abductors)
A
- second largest of the gluteal 3 muscles that lies slightly anterior and deep to gluteus maximus
- they both abducting and medially rotate the hip
- has an important role in controlling the level of the pelvis. when weak it can cause pelvis on opposite side to drop
- origin: lateral and posterior surface of ilium
- insertion: posterior and lateral surface of the upper femur
- action: abduction and medial rotation of hip
5
Q
gluteus minimus (hip abductors)
A
- smallest and deepest of 3 gluteus muscles, located directly beneath gluteus medius
- plays crucial role in stabilising the hip, especially during single leg stance
- origin: lateral surface of the ilium
- insertion: anterior surface of the upper femur
- action: abduction and medial rotation of the hip
6
Q
piriformis (hip abductors)
A
- located deep to gluteus maximus
- has role in stabilising the hip by helping to secure the head of the femur in the acetabulum of the pelvis
- origin: anterior surface of the sacrum
- insertion: superior surface of the upper femur
- action: abduction and lateral rotation of the hip joint
7
Q
gluteus maximus (hip extensors)
A
- largest and most superficial of 3 gluteal muscles and forms convex shape of the booty
- plays crucial role in both stability and movement
- acting inferiorly it creates strong powerful movement of the hip
- acting superiorly it stabilises the pelvis at the sacroiliac point
- origin: iliac crest, sacrum and coccyx
- insertion: upper posterior femur and IT band
- action: extension and lateral rotation of the hip
8
Q
iliacus and psoas (iliopsoas) (hip flexors)
A
- iliopsoas is the most powerful hip flexors and consists of 2 distinct muscles - iliac and psoas
- psoas is much longer than iliacus which gives it greater mechanical advantage when generating movement through a larger range
- iliacus is a strong hip flexor that works in close collab with psoas
- iliacus acts when the femur is positioned below hip and is important for both movement and stabilisation of the hip and pelvic region
- origin: lumbar spine (psoas) and iliac fossa and anterior-inferior iliac spine (iliacus)
- insertion: lesser trochanter of the femur
- action: both muscles flex the hip to approx 90 degrees. once past 90 degrees, the psoas becomes more dominant than iliacus because its spinal attachment are higher than the iliac crest.
- when feet/legs are fixed, iliacus also may assist other muscles to pull the pelvis into an anterior tilt. this pair of muscles are able to assist other muscles in this region to flex the spine
9
Q
sartorius (hip flexors)
A
- longest skeletal muscle in the body and spans the anterior surfaces of both knee and hip joint
- origin: anterior superior iliac spine
- insertion: medial condyle of the tibia
- action: acting at the hip, this muscle can assist in hip flexion, lateral rotation and abduction. Also has the ability to assist the hamstrings and gastrocnemius in flexing and medially rotating the knee
10
Q
rectus femoris (knee extensors - quadriceps)
A
- only one of the 4 muscles to cross both both the hip and knee joints
- located towards middle of the front of the thigh
- origin: anterior inferior iliac spine
- insertion: tibial tuberosity via the patella
- action: extension of the knee and flexion of the hip
11
Q
vastus medialis (knee extensors - quadriceps)
A
- most medial quadricep
- important in taking the knee through its final 20 degrees of extension and ensures patella is correctly tracked.
- muscles only cross the knee
- origin: medial surface of the femur
- insertion: tibial tuberosity via the patella
- action: extension of the knee, especially in the last 20 degrees of movement
12
Q
vastus lateralis (knee extensors - quadriceps)
A
- the most outer/lateral of quadricep muscle
- only crosses the knee so can only facilitate movement at this point
- origin: upper lateral surface of the femur
- insertion: tibial tuberosity via the patella
- action: extension of the knee
13
Q
vastus intermedius (knee extensors - quadriceps)
A
- deepest and most central of 4 quad muscles
- located deep to rectus femoris
- lies largely in central position but some of its fibres are located on the lateral aspect of the thigh
14
Q
bicep femoris (knee flexors - hamstrings)
A
- located to the back of the thigh
- only hamstring muscle to attach the tibia laterally
- it has 2 attachment points/heads
- origin: ischial tuberosity and posterior surface of the femur
- insertion: head of the fibula and lateral condyle of the tibia
- action: flexion of the knee and extension of the hip
- could equally be listed as a hip extensor
15
Q
semitendinosus (knee extensors - hamstrings)
A
- shares attachment points with semimembranosus but is considered to be more superficial
- plays significant role in counteracting forward flexion from hip during most standing activities
- origin: ischial tuberosity
- insertion: medial condyle of the tibia
- action: extension of the hip and flexion of the knee
16
Q
semimembranosus (knee extensors - hamstrings)
A
- most medial of the hamstring group
- wider, flatter and deeper than semitendinosus, which it shares very close points of attachment
- origin: ischial tuberosity
- insertion: medial condyle of the tibia
- action: extension of the hip and flexion of the knee
17
Q
gastrocnemius (ankle extensor)
A
- situated on the rear surface of the lower leg
- more superficial of 2 muscles that make up the calf group
- as it crosses the knee and the ankle, it creates movement at both these joints
- origin: posterior medial and lateral condyle of the femur
- insertion: calcaneus
- action: flexion of the knee and plantarflexion of the ankle
18
Q
soleus (ankle extensors)
A
- deep to gastrocnemius muscle and attaches below the knee
- only crosses the ankle and is more dominant when knee is flexed at an angle of 90 degrees or less.
- origin: upper posterior surface of tibia and fibula
- insertion: calcaneus
- action: assists gastrocnemius in plantarflexion at the ankle from standing positions. when knee is flexed, soleus becomes the dominant plantarflexor
19
Q
tibialis posterior (ankle extensors)
A
- deepest muscle of the lower leg
- posterior to tibia
- the distal tendon passes behind the medial malleolus of the ankle/tibia, attaching to underside of foot
- this muscle is main inverter of foot, working in conjunction with tibialis anterior
- origin: posterior upper surfaces of tibia and fibula
- insertion: planter surface of tarsals and 2nd-4th metatarsals
- action: plantarflexion of the ankle and inversion of the foot at the sub-talar joint
20
Q
tibialis anterior (ankle flexor)
A
- long sheet of muscle situated to the front of the tibia bone and is important for stabilisation of the ankle
- works eccentrically during ground contact phase of a stride and concentrically during swing through phase
- origin: lateral surface of the tibia
- insertion: plantar surface of the medial tarsal and first metatarsal
- action: dorsiflexion of the ankle and inversion of the sub-talar joint
21
Q
erector spinae (spinal extensors)
A
- large group of 3 muscles (illiocostalis, longissimus and spinalis) that originates at the sacrum and lower spine
- divided into 3 distinct segments that run vertically along the length of the spine
- some sections of this muscle also assist in spinal rotation
- origin: along the length of the vertebral column, ribs and pelvis
- insertion: vertebral column and ribs
- action: extend the spine and assist in maintaining an upright posture. also can tilt pelvis anteriorly
22
Q
multifidus (spinal extensors)
A
- long, thin spinal muscle that runs parallel to the vertebral column
- located deep in spinal area
- spans from sacrum to base of the neck
- fibres arranged diagonally
- predominantly formed of type 1 fibres that enable it to maintain an upright posture over long periods of time
- origin: sacrum and lumbar vertebrae
- insertion: every second vertebra until the second cervical
- action: spinal extension
can also assist with spinal rotation
23
Q
quadratus lumborum (spinal extensors)
A
- quadrilateral shaped muscle located deep on posterior surface of lower back, connecting ribs to pelvis
- origin: iliac crest
- insertion: 12th rib and L1-L4
- action: when acting bilaterally, spinal extension.
when acting unilaterally, lateral flexion of the spine.
also works with diaphragm to depress the last rib during forced expiration
24
Q
rectus abdominis (spinal flexors)
A
- most superficial of ab muscles
- located on anterior surface of ab wall
- formed by vertical segments of muscle
- rectus means straight
- origin: pubic symphysis and pubic rest
- insertion: Xiphoid process of the sternum and 5th, 6th and 7th ribs
- action: flexes the thoracic and lumbar spine to approx 35 degrees, posteriorly rotates the pelvis by approx 10 degrees, and increases intra-abdominal pressure in conjunction with the obliques and transverse abdominis
25
internal obliques (spinal flexors)
- above transverse abdominis and below the external obliques
- form middle layer of abdominal wall
- origin: iliac crest and lumbar fascia
- insertion: 8th, 9th, 10th ribs and the linea alba
- action: when working contralaterally with the external oblique, rotation of the spine.
when working unilaterally with the external oblique, lateral flexion of the spine
26
external obliques (spinal flexors)
- form most superficial layer of the ab wall, together with rectus abdominis
- origin: lower 8 ribs
- insertion: iliac crest and linea alba
- action: when working with the contralateral internal oblique, rotation of the spine. When working unilaterally with the internal oblique, lateral flexion of spine.
27
transverse abdominis (spinal)
- deepest of ab muscles
- fibres arranged in a transverse direction
- connects medially to a broad flat sheet of connective tissue called aponeurosis
- perhaps most important spinal stabilisers due to its ability to raise intra-abdominal pressure and stiffen the spine
- largely composed of type 1 fibres
- origin: iliac crest, lower 6 ribs and thoracolumbar fascia
- insertion: linea alba and pubis
- action: compression (drawing abdomen inward), supports internal organs, raises intra-ab pressure
28
intercostals
- located between ribs and contain an internal and external division
- in total there are 22 pairs of muscles that connect each of the ribs to those directly above and below
- origin: ribs
- insertion: ribs
- action: the external intercostals primarily act to elevate the ribs during inspiration. the internal intercostals primarily act to depress the ribs during expiration.
29
pectoralis major (muscles of the shoulder joint)
- fan shaped muscle
- forms convex shape of the chest area
- crossing the shoulder joint, it controls pushing movements of the upper arm, particularly in a horizontal plane
- origin: clavicle, sternum and ribs 1-6
- insertion: anterior surface of the humerus
- action: adduction, horizontal flexion and medial rotation of the shoulder joint
30
deltoids (muscles of the shoulder joint)
- large triangular shaped muscle that form the rounded contour of the shoulder area
- cover the entire external surfaces of the glenohumerul joint, functionally it can be divided into 3 parts (anterior, posterior and lateral)
- origin: scapula and clavicle
- insertion: lateral tuberosity of the humerus
- flexion, horizontal flexion and medial rotation of the shoulder (anterior fibres). abduction of the shoulder (lateral fibres). extension, horizontal extension and lateral rotation of the shoulder (posterior fibres)
31
latissimus dorsi (muscles of the shoulder joint)
- large sheet of muscle that spans the mid-lateral region of the spine
- crossing the shoulder, it controls movement of the upper arm
- origin: T6-T12, L1-L5, Iliac crest and lower 3 ribs
- insertion: anterior surface of the humerus
- action: extension, adduction and medial rotation of the shoulder
32
teres major (muscles of the shoulder joint)
- short and thick muscle spanning posterior and lateral surface of upper back and shoulder area, between scapula and humerus
- direction in which the fibres run parallel to those of latissimus dorsi (these muscles function together)
- origin: inferior angle of the scapula
- insertion: superior and anterior surface of the humerus
- action: extension, adduction and medial rotation of the shoulder joint
33
suprasinatus (muscles of the shoulder joint - rotator cuff)
- one of four rotator cuff muscles that collectively hold the head of the humerus into the glenoid fossa of the shoulder
- individually has v important role as the initiator of the first 15-20 degrees of shoulder abduction, before the deltoid takes over
- origin: superior surface of the scapula
- insertion: superior surface of the humerus
- action: abduction of the shoulder
34
infraspinatus (muscles of the shoulder joint - rotator cuff)
- another rotator cuff muscle that is more inferior and posterior than supraspinatus
- provides stability to shoulder joint
- origin: posterior surface of the scapula
- insertion: superior and posterior surface of the humerus
- action: adduction and lateral rotation of the shoulder joint
35
teres minor (muscles of the shoulder joint - rotator cuff)
- smallest and most inferior of the rotator cuff group
- sits just beneath infraspinatus
- in some people the lower fibres of this muscle fuse with those of the infraspinatus because they are in such close proximity
- origin: lateral order of the scapula
- insertion: superior and posterior surface of the humerus
- action: adduction and lateral rotation of the shoulder joint
36
subscapulais (muscles of the shoulder joint - rotator cuff)
- deepest of rotator cuff muscles that attaches the upper anterior surface of the humerus to the anterior and medial border of the scapula.
- this portion of the rotator cuff is the only muscle in the group to create movement to the front of the body
- origin: anterior surface of the scapula
- insertion: superior anterior surface of the humerus
- action: medial rotation of the shoulder joint
37
pectoralis minor (muscles of the shoulder girdle)
- thin, flat triangular muscle that is located deep to the pectoralis major and spans diagonally and medially across the chest
- origin: 3rd, 4th and 5th ribs
- insertion: coracoid process (anterior surface of scapula)
- action: protraction of scapula, depression of shoulder girdle
38
coracobrachialis (muscles of shoulder girdle)
- located in upper medial of arm
- contributes to shoulder stability
- origin: coracoid process of the scapula
- insertion: medial surface of the humerus
- action: flexion and adduction of the humerus
39
trapezius (muscles of shoulder girdle)
- large, strong triangular shaped muscle
- located across the upper back, shoulder and neck region
- varied arrangement of its fibres enables it to perform multiple movements
- upper trapezius involved in shrugging
- mid-trapezius responsible for pulling scapulae together
- lower trapezius responsible for pulling shoulders down
- origin: base of the cranium, cervical and thoracic vertebrae
- insertion: clavicle and scapula
- action: lateral flexion and rotation of cervical vertebrae; retraction of the shoulder girdle and elevation and depression of the shoulder girdle
40
rhomboids (muscles of shoulder girdle)
- connect scapula to the ribs
- scapula stabilisers
- also help correcting posture, esp kyphosis
- minor rhomboid is superior to major portion
- origin C7-T5
- insertion: medial border of the scapula
- action: elevation and retraction of the shoulder girdle
41
serratus anterior
- large flat muscle that covers lateral surface of the thorax and is sandwiched between the ribs and scapula
- origin: upper 8/9 ribs
- insertion: medial border of the scapula
- action: protractor of scapula and shoulder complex
- also provides stability to this area
42
levator scapulae (neck extensor)
- situated deep in the posterior area of the neck
- exerts force from the superior and medial border of the scapula
- origin: C1-C4
- insertion: superior angle of scapula
- action: working bilaterally with trapezius it can elevate and retract the shoulder girdle. At the neck also assists with extension. working unilaterally it assists with lateral flexion of the neck
43
sternocleidomastoid (neck flexors)
- largest and most superficial of neck muscles
- origin: sternum and medial clavicle
- insertion: mastoid process of the temporal bone
- action: when working bilaterally, flexion of the cervical vertebrae.
when working unilaterally, lateral flexion and rotation of neck.
44
triceps (elbow extensors)
- located rear of the upper arm
- constitutes approx two thirds of the muscle tissue in this area
- muscle crosses both elbow and shoulder
- origin: superior surface of the scapula, lateral posterior surface of the humerus, posterior surface of the humerus
- insertion: superior surface of the ulna
- action: extension of the shoulder and elbow joints
45
bicep brachii (elbow flexor)
- located on front of upper arm
- crosses shoulder and elbow joint
- has two heads that arise together on scapula and join together to form a single muscle
- origin: superior surface of the scapula, anterior surface of the scapula
- insertion: radius
- action: flexion of the elbow and shoulder joint. supination of forearm
46
brachialis (elbow flexors)
- located beneath the bicep and assists with flexing the elbow, esp when shoulder is flexed
- origin: mid-surface of the humerus
- insertion: superior surface of the ulna
- action: flexion of the elbow, esp when shoulders flexed and bicep already shortened
47
brachioradialis (elbow flexor)
- located on lateral side of the forearm
- origin: distal surface of the humerus
- insertion: palm of the hand
- action: flexion of the elbow and supination of the radioulna joint
48
hip adductors
- there are 3 adductors; adductor magnus (largest), adductor brevis (smallest), adductor longus (longest)
- origin: anterior surface of the pubis
- insertion: medial surface of the femur
- action: adduction of the hip joint. adductor magnus also assists with hip extension
49
reverse action
when insertion remains fixed and origin moves towards insertion
