Lab 2:
SKELETAL MUSCLE KINESIOLOGY
Kinesiology is the study of human movement. It applies biomechanics to the musculoskeletal
system. Skeletal muscles are contractile tissues that allow the body to move through their action
(pulling) on the bones and skin attachments. Skeletal muscle has two basic parts: the contractile
muscle belly and the non-contractile tendon, which connects the muscle to the bone. It is
important to understand the relationship a muscle has with the bones they attach to. The
muscle’s function is dependent on its anatomy. Muscles have both an origin and an insertion.
The origin is the part of the muscle that attaches to the most proximal and stationary part of the
skeleton. The insertion is the muscular attachment to the bone that moves when the muscle
contracts. Several of the full skeletons in the lab have the origin and insertion labeled. The origin
is painted red and the insertion blue. It is helpful to visualize how the muscle works. Remember,
when a muscle contracts the insertion is pulled closer to the origin. Looking at the direction of the
muscle fibers and where it crosses the joint will allow you to predict its function.
Muscles work both synergistically and antagonistically with each other. The nervous system must
coordinate these muscles to work with precise timing. The primary muscles that produce a
specific motion at a particular joint are called prime movers. The hamstring muscle group is the
primary knee flexor. The prime movers may also have muscles that exert similar effects on the
joint. For example, the gastrocnemius muscles (calf) assist the hamstrings with knee flexion. It
would be considered a synergist to the hamstrings for knee flexion because they both perform
the same action.
Muscles also work antagonistically to each other. Antagonistic muscles perform the opposite or
opposing action. The biceps brachii muscle runs anterior to the elbow joint. Its primary action will
be elbow flexion. The triceps run posterior to the elbow joint, which would create elbow extension.
In order to have elbow flexion (biceps), the antagonist muscle group (triceps) would need to be
inhibited (reciprocal inhibition). The coordinated action of both agonist and antagonist is a
necessity for proper motor control.
Key Muscles and Nerve Innervation
muscle
diaphragm
external oblique
internal oblique
transverse abdominis
rectus abdominis
erector spinae
psoas major
psoas minor
multifidis
levator scapulae
nerve
phrenic (C3-5)
8-12th intercostal, iliohypogastric, ilioinguinal
8-12th intercostal, iliohypogastric, ilioinguinal
7-12th intercostal, iliohypogastric, ilioinguinal
7-12th intercostals
dorsal division of spinal nerve
lumbar plexus L2,3 (1,4)
dorsal division of spinal nerve
dorsal scapular (C5)
.
Acland Video
The Musculoskeletal Structures of the Thorax
1.
3.2.1 The bones of the thorax (4:53)
2. 3.1.7 Paravertebral muscles (4.54)
3.
4.
5.
3.2.2 Costovertebral joints (1:08)
3.2.3 First rib and clavicle (2:53)
3.2.4 Review of bones of the thorax (1:15)
1. Which bones make up the thorax?
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2. What are the 3 classifications of ribs?
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3. Describe the articulation of the costo- vertebral and transverse joints.
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4. Name the 3 joints that influence movement of the upper extremity.
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5. Name the 3 erector spinae muscles and describe their principle function.
__________________________________________________________________________
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6. Name the 2 paravertebral muscles and describe their principle function.
__________________________________________________________________________
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The Musculoskeletal Structures Around the Abdomen
6.
7.
8.
9.
3.3.1
3.3.2
3.3.3
3.3.4
Bones that support the abdomen (1:39)
Upper parts of the bony pelvis (5:22)
Review of bones of the abdomen (1:01)
The inguinal ligament (0:55)
10.
11.
12.
13.
14.
15.
3.3.5 Posterior abdominal muscles 1: erector spinae, quadratus
(2:03)
3.2.6 The diaphragm (4:15)
3.3.6 Posterior abdominal muscles 2: psoas major, iliacus (3:23)
3.3.7 Anterior abdominal muscles 1: rectus abdominis (3:52)
3.3.8 Anterior abdominal muscles 2: transversus, internal oblique
3.3.9 Anterior abdominal muscles 3: external oblique (3:03)
1. Which bones compose the boney pelvis?
__________________________________________________________________________
__________________________________________________________________________
2. What muscles make up the anterior and lateral abdonminal walls?
__________________________________________________________________________
__________________________________________________________________________
Consider the following key points in trying to identify the muscle’s action.
1. Look at both the muscle’s origin and insertion. Some skeletons in the lab will have the origin
labeled red and insertion blue. Once identified, bring the insertion closer to the origin.
2. Notice how the joint of the skeleton naturally moves. When muscles contract (shorten), they
pull its insertion toward the origin.
3. Look at the direction of the muscle fibers and the joints the muscles cross. If a muscle
crosses the joint, it will have an effect on that joint.
4. Movements produced by the muscles are based on anatomical position.
5. Use the appropriate anatomical terminology for describing the muscle’s function.
Using the Visible Body Muscle Program answer the following about the muscles listed:
1.
2.
3.
Diaphragm:
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action:
External oblique
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action:
Internal oblique
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action:
4.
Transverse abdominis
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action:
5.
Rectus abdominis
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action:
6.
Quadradus Lumborum
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action:
7.
Trapezius
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action:
8.
Latissimus dorsi
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action:
9.
Levator scapulae
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action:
10. Rhomboid major
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action:
11. Rhomboid minor
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action:
12. Serratus anterior
a. Origin:
b. Insertion:
c. Nerve innervation:
d. Action: