1.1 How Skeletal Muscles Produce
Movement
1.3 Principal Actions of Muscles
1.4 Principal Skeletal Muscles
1.5 Intramuscular (IM) Injections
1.7 Hip, Buttock, and Back Injuries
1
Muscular Anatomy
1.1
How
Skeletal Muscles Produce Movement
Back Table of Contents References
1.1.1 Introduction
1.1.1.1 Muscle Tissue
1.1.1.1.1
1.1.1.2 Muscular System
1.1.1.2.1
1.1.2
Origin
and Insertion
1.1.2.1
1.1.3
Lever
Systems and Leverage
1.1.3.1
1.1.3.2
Levers
1.1.3.2.1
1.1.3.2.2
First-class
Levers
1.1.3.2.2.1
1.1.3.2.3
Second-class
levers
1.1.3.2.3.1
1.1.3.2.4
Third-class
Levers
1.1.3.2.4.1
1.1.3.3
Leverage
1.1.3.3.1
1.1.4
Arrangement
of Fasciculi
1.1.4.1
1.1.4.2
Parallel
1.1.4.2.1
1.1.4.3
Fusiform
1.1.4.3.1
1.1.4.4
Convergent
1.1.4.4.1
1.1.4.5
Pennate
1.1.4.5.1
1.1.4.6
Unipennate
1.1.4.6.1
1.1.4.7
Bipennate
1.1.4.7.1
1.1.4.8
Circular
1.1.4.8.1
1.1.4.9
Fascicular
Arrangement
1.1.4.9.1
1.1.5
Group
Actions
1.1.5.1
1.1.5.2
Prime
Mover (Agonist)
1.1.5.2.1
1.1.5.3
Antagonist
1.1.5.3.1
1.1.5.4
Synergists
1.1.5.4.1
1.1.5.5
Fixators
1.1.5.5.1
1.2
Naming
Skeletal Muscles
1.2.1
1.2.2
Direction
of Muscle Fibers
1.2.2.1
1.2.3
Location
1.2.3.1
1.2.4
Size
1.2.4.1
1.2.5
Number
of Origins
1.2.5.1
1.2.6
Shape
1.2.6.1
1.2.7
Origin
and Insertion
1.2.7.1
1.2.8
Action
1.2.8.1
1.3
Principal
Actions of Muscles
1.3.1
Flexor
1.3.1.1
Definition
1.3.1.1.1
1.3.1.2
Example
1.3.1.2.1
1.3.2
Extensor
1.3.2.1
Definition
1.3.2.1.1
1.3.2.2
Example
1.3.2.2.1
1.3.3
Abductor
1.3.3.1
Definition
1.3.3.1.1
1.3.3.2
Example
1.3.3.2.1
1.3.4
Adductor
1.3.4.1
Definition
1.3.4.1.1
1.3.4.2
Example
1.3.4.2.1
1.3.5
Levator
1.3.5.1
Definition
1.3.5.1.1
1.3.5.2
Example
1.3.5.2.1
1.3.6
Depressor
1.3.6.1
Definition
1.3.6.1.1
1.3.6.2
Example
1.3.6.2.1
1.3.7
Supinator
1.3.7.1
Definition
1.3.7.1.1
1.3.7.2
Example
1.3.7.2.1
1.3.8
Pronator
1.3.8.1
Definition
1.3.8.1.1
1.3.8.2
Example
1.3.8.2.1
1.3.9
Sphincter
1.3.9.1
Definition
1.3.9.1.1
1.3.9.2
Example
1.3.9.2.1
1.3.10
Tensor
1.3.10.1
Definition
1.3.10.1.1
1.3.10.2
Example
1.3.10.2.1
1.3.11
Rotator
1.3.11.1
Definition
1.3.11.1.1
1.3.11.2
Example
1.3.11.2.1
1.4 Principal Skeletal Muscles
1.4.1
Introduction
1.4.1.1
1.4.2
Grouped
Muscles
1.4.2.1 Facial Expression *
Back Table
of Contents References
1.4.2.1.1 Facial muscles communicate feelings in a way that words may fail. These muscles are innervated by the Facial Nerve (VII), which originates in the Pons (?) located in the brain stem. The facial nerve has a direct connection to the emotional centers of the brain. If you look closely at a Person's Facial expression, you are seeing uncensored, raw, preverbal feelings. That is, before person has a chance to think about what they are going to say their Facial muscles express feelings. No matter what your profession or specialty reading a person's face and interpreting the meaning of facial expression is an important part of the assessment process. For example, if you were instructing a person on how to stretch a muscle, a furrowed brow or frown may mean they do not understand. A pre-treatment pain assessment may be accompanied by a grimace, which is absent in post assessment. Facial muscles may not tell you exactly what a person is feeling but they should give you a way to start asking questions.
1.4.2.1.2 Facial muscles lie within the layers of superficial fascia. They arise from fascia or bones of the skull and insert into the skin. Because of their insertion, the muscles of Facial expression move the skin rather than a joint when they contract.
1.4.2.1.3
The facial muscles (muscles of expression) arise from
the mesoderm of the hyoid arch. The facial nerve enters this mass before it
begins to split, and as the muscle mass spreads out over the face and head and
neck it splits more or less incompletely into the various muscles.
1.4.2.1.4
Gray’s
Anatomy
1.4.2.1.4.1
Facial
Muscles
1.4.2.1.5
Facial
Muscles
Back Table
of Contents References
1.4.2.1.5.1
Buccinator B16E16
(Consternation= Amazement & Confusion)
1.4.2.1.5.1.1 If you press your cheeks firmly against the side teeth and pull back the angle of the mouth as in blowing a trumpet you have just activated the buccinator muscle. The buccinator has an origin in the upper and lower jaw and has its insertion into the Orbicularis Oris near the angle of the mouth.
1.4.2.1.5.2
Corrugator
Supercilii B21E21 (Trepidation=Uncertain agitation)
1.4.2.1.5.2.1 Draw your eyebrows together as in frowning. The corrugator supercilii inserts just above your mid eyebrow goes underneath your eyebrow and has its origin near the inner part of your upper nose.
1.4.2.1.5.3
Depressor
Anguli Oris (Available in Full Version Only)
1.4.2.1.5.4
Depressor
Labii Inferioris (Available on Full Version Only)
1.4.2.1.5.5
Depressor
Septi (Available on Full Version Only)
1.4.2.1.5.6
Frontalis
(Surprise) (Available on Full Version Only)
1.4.2.1.5.7
Incisivus
Labii Inferioris (Available on Full Version Only)
1.4.2.1.5.8
Incisivus
Labii Superioris (Available on Full Version Only)
1.4.2.1.5.9
Levator
Anguli Oris (Caninus) (Available on Full Version Only)
1.4.2.1.5.10
Levator Labii
Superioris (Available on Full Version Only)
1.4.2.1.5.11
Levator Labii
Superioris Alaeque Nasi (Available on Full Version Only)
1.4.2.1.5.12
Mentalis (Available on Full Version Only)
1.4.2.1.5.13
Nasalis, Alar
Portion (Available on Full Version Only)
1.4.2.1.5.14
Nasalis
(Compressor & Dilator naris) (Available on Full Version Only)
1.4.2.1.5.15
Occipitalis (Available on Full Version Only)
1.4.2.1.5.16
Orbicularis
Oculi (Available on Full Version Only)
1.4.2.1.5.17
Orbicularis
Oris (Available on Full Version Only)
1.4.2.1.5.18
Platysma (Available on Full Version Only)
1.4.2.1.5.19
Procerus (Available on Full Version Only)
1.4.2.1.5.20
Risorius (Available on Full Version Only)
1.4.2.1.5.21
Zygomaticus
Major (Available on Full Version Only)
1.4.2.1.5.22
Zygomaticus Minor
(Available on Full Version Only)
1.4.2.2
Lower
Jaw
Back Table
of Contents References
1.4.2.2.1
Overview
1.4.2.2.1.1
These muscles
are involved in biting and chewing but also help you with speech.
1.4.2.2.2
Gray’s
Anatomy
1.4.2.2.2.1
Lower
Jaw Anatomy
1.4.2.2.2.2
Muscles
of Mastication
1.4.2.2.3
Lower Jaw Muscles
(Muscles of Mastication)
1.4.2.2.3.1
Lateral
Pterygoid
1.4.2.2.3.2
Masseter
1.4.2.2.3.3
Medial
Pterygoid
1.4.2.2.3.4
Temporalis
1.4.2.3
Eyeball
Muscles *
Back Table
of Contents References
1.4.2.3.1
Overview
1.4.2.3.1.1
There are two
types of eyeball muscles, extrinsic and intrinsic. Extrinsic eyeball muscles are attached on the outside of the
eyeball and insert in its outer surface (sclera). The intrinsic eyeball muscles
originate and insert entirely within the eyeball.
1.4.2.3.1.2
Two sets of
eyeball muscles allow you to roll your eyes up, down, left, or right. These muscles are indicated by their
respective names superior, inferior, lateral, and medial. The oblique eyeball muscles rotate the
eyeball on its axis. These muscles are some of the quickest acting and
precisely controlled muscles in the body.
1.4.2.3.2
Gray’s
Anatomy
1.4.2.3.2.1
Eyeball
Anatomy
1.4.2.3.2.2
Eyeball
Muscles
1.4.2.3.3
Extrinsic
Eyeball Muscles
1.4.2.3.3.1
Inferior
Oblique
1.4.2.3.3.2
Inferior
Rectus
1.4.2.3.3.3
Lateral
Rectus
1.4.2.3.3.4
Medial Rectus
1.4.2.3.3.5
Superior
Oblique
1.4.2.3.3.6
Superior
Rectus
1.4.2.3.4
Intrinsic
Eyeball Muscles
1.4.2.3.4.1
Ciliary
Muscle B18E18
1.4.2.3.4.1.1 If you want to read the fine print (near vision) or see a road sign (Distant vision) far away, you are putting your ciliary muscle to work. It has its origin into the inner part of the eyeball wall and inserts into tissue, which attaches to the lens and changes its shape.
1.4.2.3.4.2
Dilator
Pupillae
1.4.2.3.4.3
Levator
Palpebrae Superioris
1.4.2.3.4.4
Sphincter
Pupillae
1.4.2.4
Tongue
Muscles
Back Table
of Contents References
1.4.2.4.1
Introduction
1.4.2.4.1.1
The extrinsic
muscles of the tongue are attached and insert on the outside of the tongue. The intrinsic muscles of the tongue are
attached and insert on the inside of the tongue. The tongue is divided down the center by a median fibrous septum
and the muscles of the tongue are mirrored on either side of the septum.
1.4.2.4.2
Gray’s
Anatomy
1.4.2.4.2.1
Tongue
Muscles
1.4.2.4.3
Extrinsic
Tongue Muscles
1.4.2.4.3.1
Genioglossus
1.4.2.4.3.2
Hyoglossus
1.4.2.4.3.3
Palatoglossus
1.4.2.4.3.4
Styloglossus
1.4.2.4.4
Intrinsic
Tongue Muscles
1.4.2.4.4.1
Inferior
Longitudinal Lingualis
1.4.2.4.4.2
Superior
Longitudinal Lingualis
1.4.2.4.4.3
Transverse
Lingualis (Body of Tongue)
1.4.2.4.4.4
Vertical
Lingualis (Body of Tongue)
1.4.2.5
Soft
Palate
Back Table of Contents References
1.4.2.5.1
Levator Veli
Palatini
1.4.2.5.2
Musculus
Uvulae
1.4.2.5.3
Palatoglossus
1.4.2.5.4
Palatopharyngeus
1.4.2.5.5
Tensor Veli
Palatini
1.4.2.6
Pharynx *
Back Table of Contents References
1.4.2.6.1 Introduction
1.4.2.6.1.1 The pharynx helps you swallow your food through reflexive action. That is so you do not have to think about it. If you have ever been down by the seashore and stuck your finger in a sea urchin you know how the pharynx works. As you stick your finger in the sea urchin, it both grasps your finger and pulls it in. The Pharynx works in the same way with a circular layer of the pharynx grasping the food particle and the longitudinal layer alternately creating space and pushing the particle into this space. The Pharynx (throat) is a muscular funnel posterior to the nasal cavities, mouth, and larynx (voice box). The two layers as mentioned above are the circular layer, which is composed of three constrictors each overlapping the one above. The remaining muscles comprise the second longitudinal layer.
1.4.2.6.2 Gray’s Anatomy
1.4.2.6.2.1 Pharynx Muscles
1.4.2.6.3 Pharynx Muscles
1.4.2.6.3.1
Pharynx
Circular Layer
1.4.2.6.3.1.1 Inferior Pharyngeal Constrictor
1.4.2.6.3.1.2 Middle Pharyngeal Constrictor
1.4.2.6.3.1.3 Superior Pharyngeal Constrictor
1.4.2.6.3.2
Pharynx
Longitudinal Layer
1.4.2.6.3.2.1 Cricopharyngeus B23E23
1.4.2.6.3.2.1.1 If you have ever wondered why you do not breath into your stomach when you take a breath into your lungs you are going to find out now. It is because the Cricopharyngeus constricts when you take a breath and relaxes as when you swallow food.
1.4.2.6.3.2.2 Palatopharyngeus
1.4.2.6.3.2.3 Salpingopharyngeus
1.4.2.6.3.2.4 Stylopharyngeus
1.4.2.7
Oral
Cavity
Back Table of Contents References
1.4.2.7.1
Introduction
1.4.2.7.1.1
1.4.2.7.2 Gray’s Anatomy
1.4.2.7.2.1
Oral Cavity Anatomy
1.4.2.7.2.2
Oral Cavity Muscles
1.4.2.7.3 Oral Cavity Muscles
1.4.2.7.3.1 Digastric Ant & Post Belly (Suprahyoid)
1.4.2.7.3.2 Geniohyoid (Suprahyoid)
1.4.2.7.3.3 Mylohyoid (Suprahyoid)
1.4.2.7.3.4 Stylohyoid (Suprahyoid)
1.4.2.8 Larynx *
Back Table of Contents References
1.4.2.8.1 Introduction
1.4.2.8.1.1 The larynx has been called the voice box but it is really less like a box and more like a jug. In fact, one of the intrinsic muscles of the larynx the posterior cricoarytenoid is based on the word arytaina, which means shaped like a jug. If you take a jug, fill it with water and blow on the opening just right you will get a sound. If you fill the jug with more water, (decreasing the space in the jug) you will get a higher sound when you blow through the opening. Likewise, if you pour water out of the jug (increasing the space in the jug) and blow on the opening you will get a lower sound. You could also change the pitch of the sound by changing the size of the opening of the jug. When the opening of the jug is smaller, the sound is higher. When the opening of the jug is larger, the sound is lower. The opening of the larynx is called the glottis. The glottis consists of two vocal cords and an intervening space called the rima glottidis. The rima glottidis is just like the opening of the jug. The muscles that control how large this opening is are the intrinsic muscles of the larynx. The muscles that control how large the space is after the opening are the extrinsic muscles of the larynx. The extrinsic muscles of the larynx depress the hyoid bone (a crescent shaped bone circling the space below the glottis). The extrinsic muscles of the larynx elevate and depress the thyroid cartilage. The position of the hyoid bone and thyroid cartilage help control the size of the space after the opening of the larynx (glottis). In adults, the larynx is larger in males than in females and this as you might guess is why men have deeper voices (generally speaking) than women do. Until puberty, the larynx is about the same size between girls and boys. After puberty, the size of the larynx does not change that much in girls but in boys the cartilages are enlarged and the thyroid cartilage becomes prominent, while the length of the rima glottidis is nearly doubled. In boys, this creates a more prominent bulge (Adams apple) and deepens the voice.
1.4.2.8.1.2 In summary, the muscles of the larynx are divided into two divisions, extrinsic and intrinsic. The extrinsic muscles of the larynx depress the hyoid bone, depress, and elevate the thyroid Cartilage. The intrinsic muscles of the larynx lengthen and shorten the vocal folds and open and close the glottis.
1.4.2.8.2 Gray’s Anatomy
1.4.2.8.2.1 Larynx Muscles
1.4.2.8.3 Larynx Muscles
1.4.2.8.3.1 Larynx Extrinsic
1.4.2.8.3.1.1 Omohyoid Superior & Inferior (Infrahyoid)
1.4.2.8.3.1.2 Sternohyoid (Infrahyoid)
1.4.2.8.3.1.3 Sternothyroid (Infrahyoid)
1.4.2.8.3.1.4 Thyrohyoid (Infrahyoid)
1.4.2.8.3.2 Larynx Intrinsic
1.4.2.8.3.2.1 Cricoarytenoid Lateral & Posterior B22E22
1.4.2.8.3.2.1.1 These muscles help you change the pitch of your voice. The lateral cricoarytenoid helps close the opening (glottis) thus raising the pitch of your voice. The posterior cricoarytenoid helps open the glottis thus lowering the pitch of your voice.
1.4.2.8.3.2.2 Cricothyroid B24E24
1.4.2.8.3.2.2.1 If you imagine the strings of a violin like the vocal cords when you tighten them, you will get a higher pitch, which is exactly what the cricothyroid does. This muscle produces elongation of the vocal folds thus raising the pitch of your voice so you can hit all those high notes when your singing in the shower.
1.4.2.8.3.2.3 Oblique Arytenoid & Aryepiglotticus
1.4.2.8.3.2.4 Thyroarytenoid Vocalis & Thyroepiglotticus
1.4.2.8.3.2.5 Transverse Arytenoid
1.4.2.9 Head Movement
Back Table
of Contents References
1.4.2.9.1 Longissimus Capitis
1.4.2.9.2 Semispinalis Capitis
1.4.2.9.3 Splenius Capitis
1.4.2.9.4 Sternocleidomastoid
1.4.2.10 Abdominal Wall
Back Table
of Contents References
1.4.2.10.1 External Abdominal Oblique=Ant Div
1.4.2.10.2 External Abdominal Oblique=Lat Div
1.4.2.10.3 Internal Abdominal Oblique=Ant Div
1.4.2.10.4 Internal Abdominal Oblique=Lat Div
1.4.2.10.5 Pyramidalis
1.4.2.10.6 Quadratus Lumborum
1.4.2.10.7 Rectus Abdominis
1.4.2.10.8 Transversus Abdominis
1.4.2.11 Breathing
Back Table
of Contents References
1.4.2.11.1 Diaphragm
1.4.2.11.2 External Intercostals
1.4.2.11.3 Levatores Costarum Breves
1.4.2.11.4 Levatores Costarum Longis
1.4.2.11.5 Quadratus Lumborum
1.4.2.11.6 Serratus Posterior Inferior
1.4.2.11.7 Serratus Posterior Superior
1.4.2.12 Pelvic Floor *
Back Table of Contents References
1.4.2.12.1
Introduction
1.4.2.12.1.1
The
pelvic floor muscles (together referred to as the pelvic diaphragm) supply
support to the visceral cavity (abdominal organs) at the pelvic opening roughly
bordered by the coccyx (posterior) ischial tuberosity (lateral) and pubic ramus
(anterior). These muscles are pierced by the anal canal and urethra (Male &
female) and by the vagina (female).
1.4.2.12.2
Gray’s
Anatomy
1.4.2.12.2.1
Pelvic Floor Muscles
1.4.2.12.3
Pelvic
Floor Muscles
1.4.2.12.3.1 Coccygeus (Ischiococcygeus) B19E19
1.4.2.12.3.1.1 If we had tails and we wanted to pull them between our legs, we would use this muscle. This muscle pulls the tailbone (coccyx) forward after defecation and has some pelvic floor support function.
1.4.2.12.3.2 Levator Ani, Iliac Part (Iliococcygeus)
1.4.2.12.3.3 Levator Ani, Pubic Part (Pubococcygeus)
1.4.2.12.3.4 Sphincter Ani Externs
1.4.2.13 Perineum *
Back Table of Contents References
1.4.2.13.1
Introduction
1.4.2.13.1.1
The
peroneal muscles share the same borders in the diamond shaped pelvic opening as
the pelvic floor muscles that is; bordered by the coccyx (posterior) ischial
tuberosity (lateral) and pubic ramus (anterior). Although the peroneal muscles
provide some support, function their main actions aide the urogenital function.
A transverse line drawn between the ischial tuberosities divides the perineum
into an anterior urogenital triangle that contains the external genitals and a
posterior anal triangle that contains the anus. The urogenital diaphragm is
composed of the deep transverse Perineus, the urethral sphincter and a fibrous
membrane. The urogenital ducts are surrounded by the urogenital diaphragm,
which provide support to the pelvic floor.
1.4.2.13.2
Gray’s
Anatomy
1.4.2.13.2.1
Perineal Muscles
1.4.2.13.3
Perineal
Muscles
1.4.2.13.3.1 Bulbocavernosus (Bulbospongiosus) B17E17
1.4.2.13.3.1.1 This is an X-Rated muscle so if you do not like sex talk stop reading this. In addition, if you are underage you will have to get your parents permission to continue. This muscle helps with ejaculation and erection (men). It also increases the vaginal orifice and assists in erection of the clitoris (women).
1.4.2.13.3.2 External Anal Sphincter
1.4.2.13.3.3 Ischiocavernosus
1.4.2.13.3.4 Superficial Transverse Perineus (Superficialis)
1.4.2.13.3.5 Transverse Perineus (Profundus)
1.4.2.13.3.6 Urethral Sphincter
1.4.2.14 Pectoral (Shoulder) Girdle
Back Table of Contents References
1.4.2.14.1
Introduction
1.4.2.14.1.1
1.4.2.14.2
Gray’s
Anatomy
1.4.2.14.2.1
1.4.2.14.3
Pectoral
Muscles
1.4.2.14.3.1
Anterior
1.4.2.14.3.1.1
Pectoralis
Minor
1.4.2.14.3.1.2
Serratus
Anterior
1.4.2.14.3.1.3
Subclavius
1.4.2.14.3.2
Posterior
1.4.2.14.3.2.1 Levator Scapulae
1.4.2.14.3.2.2 Rhomboid Major
1.4.2.14.3.2.3 Rhomboid Minor
1.4.2.14.3.2.4 Trapezius Lower
1.4.2.14.3.2.5 Trapezius Middle
1.4.2.14.3.2.6 Trapezius Upper
1.4.2.15 Arm *
Back Table of Contents References
1.4.2.15.1
Introduction
1.4.2.15.1.1
The
glenoid cavity is a shallow joint made spacious and deep by the Glenohumeral
ligaments, which surround and protect it.
The arm is then able to move in all directions (Circumduction) and yet
at the same time have power and strength. Surrounding the glenoid ligaments are
the four rotator cuff muscles (so named because they attach to a contiguous
tendinous cuff which surrounds the joint), which further reinforce the joint
and assist in guiding the half domed head of the humerus as it moves through
its range. The remaining five muscles are more superficial to the rotator cuff
and provide the power to the joint. These are termed the axial arm muscles,
which attach to the axial skeleton and the scapular arm muscles because they
attach to the scapula. Nine muscles
cross the shoulder joint to move the upper arm. With the exception of the
Pectoralis and Latissimus dorsi, which originate on the axial skeleton the remaining
seven muscles, all originate from the scapula.
1.4.2.15.2
Gray’s
Anatomy
1.4.2.15.2.1
Arm Muscles 1
1.4.2.15.2.2
Arm Muscles 2
1.4.2.15.2.3
Arm Muscles 3
1.4.2.15.2.4
Arm Muscles 4
1.4.2.15.3
Arm
Muscles
1.4.2.15.3.1 Axial
1.4.2.15.3.1.1 Latissimus Dorsi
1.4.2.15.3.1.2 Pectoralis Major Clavicular
1.4.2.15.3.1.3 Pectoralis Major Sternal
1.4.2.15.3.2 Scapular
1.4.2.15.3.2.1 Coracobrachialis B20E20
1.4.2.15.3.2.1.1 This muscle is well developed on you if you like to hug your friends and family. Its origin is on the coracoid process of the scapula and it is inserted in the humerus. It acts to horizontally flex and adduct the arm.
1.4.2.15.3.2.2 Deltoid Anterior B25E25
1.4.2.15.3.2.2.1 This muscle gives you a broad shouldered physique and is a strong-arm abductor, medial rotator and horizontal flexor. The origin of the anterior deltoid is on the anterior part of the clavicle and it inserts into the deltoid tuberosity of the humerus. It is innervated by the axillary nerve with nerve roots of C5 & C6.
1.4.2.15.3.2.3 Deltoid Middle
1.4.2.15.3.2.4 Deltoid Posterior
1.4.2.15.3.2.5 Teres Major
1.4.2.15.3.3 Arm Scapular Rotator Cuff
1.4.2.15.3.3.1 Infraspinatus
1.4.2.15.3.3.2 Subscapularis
1.4.2.15.3.3.3 Supraspinatus
1.4.2.15.3.3.4 Teres Minor
1.4.2.16 Forearm (Radius and Ulna) *
Back Table of Contents References
1.4.2.16.1
Introduction
1.4.2.16.1.1
The
primary motions of the forearm muscles are flexion, extension, Pronation and
Supination. These motions reflect the motions allowed by the joints involved.
For example, the humeral ulnar joint is a hinge joint allowing for only two
motions flexion and extension. The proximal and distal radio-ulnar joint is a
trochoid or pivot joint allowing for axial rotation or Pronation and
Supination.
1.4.2.16.2
Gray’s
Anatomy
1.4.2.16.2.1
Arm
1.4.2.16.2.2
Forearm
1.4.2.16.2.3
Non Web Based
Links
1.4.2.16.2.3.1
Arm
1.4.2.16.2.3.2
Forearm
1.4.2.16.3
Forearm
Muscles
1.4.2.16.3.1 Forearm Flexors
1.4.2.16.3.1.1 Biceps Brachii B12E12
1.4.2.16.3.1.1.1 This muscle is the most visible and superficial muscle of the upper arm and one of the primary arm flexors. The origin of the biceps brachii is on the supraglenoid tubercle of the scapula & Apex of coracoid process of the scapula. It inserts on the Radial tuberosity & bicipital aponeurosis. It is innervated by the musculocutaneous nerve with nerve roots of C5 & C6.
1.4.2.16.3.1.2 Brachialis B14E14
1.4.2.16.3.1.2.1 The brachialis lies deep to the biceps brachii and although less visible than the biceps it is also a powerhouse for forearm flexion. Its origin is on the lower humerus and it inserts on the ulna. It is innervated by the musculocutaneous and radial nerves with nerve roots of C5, C6, and C7.
1.4.2.16.3.1.3 Brachioradialis B15E15
1.4.2.16.3.1.3.1 The brachioradialis helps flex the forearm and is involved in both pronation and supination. This muscle inserts on the lateral supracondylar ridge of the humerus and its origin is on the radius. It is innervated by the radial nerve with nerve roots of C5, C6, and C7.
1.4.2.16.3.2 Forearm Extensors
1.4.2.16.3.2.1 Anconeus B11E11
1.4.2.16.3.2.1.1 This is a small muscle at the back of the elbow and helps the triceps extend the elbow joint and pronate the radio-ulnar joint. The anconeus has its origin on the humerus and inserts on the ulna. Its nerve supply is the radial nerve with nerve roots of C7, C8, and T1.
1.4.2.16.3.2.2 Triceps Brachii
1.4.2.16.3.3 Forearm Pronators
1.4.2.16.3.3.1 Pronator Quadratus
1.4.2.16.3.3.2 Pronator Teres
1.4.2.16.3.4 Forearm Supinator
1.4.2.16.3.4.1 Supinator
1.4.2.17 Wrist, Hand, and Fingers *
Back Table of Contents References
1.4.2.17.1
Introduction
1.4.2.17.1.1
The
muscles that move the wrist, hand and fingers are divided into two groups
anterior (flexors) and posterior (extensors). Both of these groups are again
divided into two groups superficial and deep. The anterior (flexor) group
include muscles, which have their origin at the humerus, ulna, and or radius
and insert on the carpals, metacarpals, and phalanges of the hand. The
posterior (extensor) group also have
their origin on the humerus, ulna, and or radius and insert on the metacarpals,
and phalanges of the hand. There are thickened bands of facia at the wrist fix
in place the tendons of both the anterior (flexors) and posterior (extensor)
tendons. The anterior group of flexor tendons is fixed by the flexor
retinaculum (transverse carpal ligament) and the posterior (extensor group is
fixed by the extensor retinaculum (dorsal carpal ligament). The flexor
retinaculum (transverse carpal ligament) is located over the palmar surface of
the carpal bones over which pass the long flexor tendons of the fingers and
wrist and the median nerve. The
extensor retinaculum (dorsal carpal ligament) is located over the dorsal
surface of the carpal bones over which pass the extensor tendons of the wrist
and fingers. The tendons are all surrounded by tendinous sheaths through which
the tendons slide.
1.4.2.17.2
Gray’s
Anatomy
1.4.2.17.2.1
Wrist, Hand, and Finger Muscles
1.4.2.17.3
Wrist,
Hand, and Finger Muscles
1.4.2.17.3.1 Anterior Flexors Superficial
1.4.2.17.3.1.1 Flexor Carpi Radialis
1.4.2.17.3.1.2 Flexor Carpi Ulnaris
1.4.2.17.3.1.3 Flexor Digitorum Superficialis
1.4.2.17.3.1.4 Palmaris Longus
1.4.2.17.3.2 Anterior Flexors Deep
1.4.2.17.3.2.1 Flexor Digitorum Profundus
1.4.2.17.3.2.2 Flexor Pollicis Longus
1.4.2.17.3.3 Posterior Extensors Superficial
1.4.2.17.3.3.1 Extensor Carpi Radialis Brevis
1.4.2.17.3.3.2 Extensor Carpi Radialis Longus
1.4.2.17.3.3.3 Extensor Carpi Ulnaris
1.4.2.17.3.3.4 Extensor Digiti Minimi
1.4.2.17.3.3.5 Extensor Digitorum
1.4.2.17.3.4 Posterior Extensors Deep
1.4.2.17.3.4.1 Abductor Pollicis Longus B5E5
1.4.2.17.3.4.1.1 The abductor pollicis longus abducts and extends the thumb. This muscle has its origin on the posterior part of the ulna and radius and it inserts on the radial proximal part of the thumb (1st metacarpal). The nerve supply is the posterior interosseous nerve (deep radial nerve) with nerve roots of C7 and C8.
1.4.2.17.3.4.2 Extensor Indicis
1.4.2.17.3.4.3 Extensor Pollicis Brevis
1.4.2.17.3.4.4 Extensor Pollicis Longus
1.4.2.18 Hand-Intrinsic *
Back Table of Contents References
1.4.2.18.1 Introduction
1.4.2.18.1.1 All of these muscles have their origins and insertion within the hand and are responsible for the intricate and precise movements, which are unique to the human hand.
1.4.2.18.1.2 The intrinsic muscles of the hand can be divided into three groups.
1.4.2.18.1.2.1 Four Thenar (THE-nar), which act on the thumb and form the thenar eminence
1.4.2.18.1.2.2 Four Hypothenar (Hi-po-the-nar) muscles which act on the little finger and form the hypothenar eminence
1.4.2.18.1.2.3 Eleven intermediate (mid palmar) muscles act on all three digits except the thumb.
1.4.2.18.1.3 Injury to the intrinsic muscles of the hand can result in permanent disability. When you think about all the things you do with your hand this is no surprise
1.4.2.18.1.4 The thumb is the most important of all the fingers because it opposes all of the other fingers and allows for precise movements, gripping and pinching.
1.4.2.18.1.5 The intrinsic muscles of the hand are responsible for the following movements
1.4.2.18.1.5.1 Free motion
1.4.2.18.1.5.2 Power grip
1.4.2.18.1.5.2.1 Forcible movement of the fingers and thumb against the palm, as is squeezing
1.4.2.18.1.5.3 Precision handling
1.4.2.18.1.5.3.1 Change in position of the handed object that requires exact control of finger and thumb positions, as in winding a watch or threading a needle.
1.4.2.18.1.5.4 Pinch
1.4.2.18.1.5.4.1 Compression between the thumb and index finger or between the thumb and first two fingers
1.4.2.18.1.6 Movement of the fingers and thumb are outlined in the following linked section. Fingers
1.4.2.18.2 Gray’s Anatomy
1.4.2.18.2.1 Intrinsic Hand Muscles
1.4.2.18.3 Intrinsic Hand Muscles
1.4.2.18.3.1 Thenar
1.4.2.18.3.1.1 Abductor Pollicis Brevis B4E4
1.4.2.18.3.1.1.1 This muscle acts to abduct and medially rotate the proximal phalanx and metacarpal of the thumb. The origin of this muscle is on the carpal bones and it inserts at the base of the proximal phalanx of the thumb. The abductor pollicis brevis is innervated by the median nerve with nerve roots of C8 and T1.
1.4.2.18.3.1.2 Adductor Pollicis B10E10
1.4.2.18.3.1.2.1 Both heads of the adductor pollicis flex and adduct the big toe. The oblique head of the adductor pollicis ahs an origin at the bases of the 2nd, 3rd and 4th metatarsals and the transverse head has an origin at the plantar metatarsophalangeal ligaments of the 3rd, 4th and 5th toes. Both heads of the adductor pollicis insert at the lateral side of base of proximal phalanx of big toe. This muscle is innervated by the lateral plantar nerve with nerve roots of S2 and S3.
1.4.2.18.3.1.3 Flexor Pollicis Brevis
1.4.2.18.3.1.4 Opponens Pollicis
1.4.2.18.3.2 Hypothenar
1.4.2.18.3.2.1 Abductor Digiti Minimi (Hand) B2E2
1.4.2.18.3.2.1.1 This muscle abducts the little finger attaching at the Pisiform bone on the hand (the big bump just above the inside of the wrist crease) and at the proximal phalanx
1.4.2.18.3.2.1.2 To catch or throw a ball this muscle helps you to adjust your grip
1.4.2.18.3.2.1.3 In the anatomical neutral standing posture arms at side palms facing out abduction of the little finger is away from the midline of the palm drawn through the middle finger.
1.4.2.18.3.2.1.4 The abductor digiti minimi is innervated by the Ulnar (Deep Branch) nerve and its nerve roots are C8 and T1.
1.4.2.18.3.2.2 Flexor Digiti Minimi Brevis (Hand)
1.4.2.18.3.2.3 Opponens Digiti Minimi
1.4.2.18.3.2.4 Palmaris Brevis
1.4.2.18.3.3 Intermediate (Midpalmar)
1.4.2.18.3.3.1 Dorsal Interossei (Hand)
1.4.2.18.3.3.2 Lumbricals (Hand)
1.4.2.18.3.3.3 Palmar Interossei (Hand)
1.4.2.19 Vertebral Column Illus 10*
Back Table of Contents References
1.4.2.19.1
Introduction
1.4.2.19.1.1
The
primary action of the muscles of the vertebral column is extension of the spine
with some of the muscles laterally flexing, rotating, and flexing the spine.
The attachments of the muscles of the vertebral column are varied and complex
but can be grouped according to the direction and length of the muscle fibres.
Several examples will serve to illustrate this method of grouping. The Splenius
group arises from the midline and run laterally and superiorly to their
insertions. The erector spinae (sacrospinalis) group arises from the midline
near the spine. These muscles can also begin laterally but in both cases, the
erector spinae is placed longitudinally, from its initial origin. The
Transversospinalis group arise laterally, but run toward the midline. The
segmental group run between spinous processes or transverse processes of
vertebrae. Some of the abdominal wall muscles including the quadratus lumborum
and the rectus abdominis also move the vertebral column.
1.4.2.19.1.2
Muscles,
which are innervated by the anterior or dorsal rami of the lumbar spinal
nerves, may contribute to postural problems if the nerves that supply them are
irritated.
1.4.2.19.1.3
Although
there are many muscles in the lower back, which can affect the structure and
press on sensitive tissue a few stand out for review. These muscles are
susceptible to lumbar nerve dysfunction and may be either too weak or
contracted as a result.
1.4.2.19.1.4
The
iliocostalis lumborum, quadratus lumborum, longissimus thoracis, spinalis
thoracis, & multifidus, can in unilateral action laterally flex the spine
or bilaterally extend the spine if contracted. All of these muscles can tug on
the ribs and further exacerbate the dorsal rami of the thoracic nerves.
1.4.2.19.1.5
The
rotatores brevis/longus, multifidus can in unilateral action rotate the spine
to the opposite side or bilaterally extend the spine if contracted.
1.4.2.19.1.6
The
above muscles, which extend the spine, can be responsible for increasing
lordosis.
1.4.2.19.1.7
Most
of the buttocks muscles and leg muscles are innervated by the lower lumbar
vertebrae and the contraction of the larger buttocks muscles results in hip
extension which would tend to flatten the lordotic curve.
1.4.2.19.1.8 When postural problems are noted, check the dermatomes to assess whether spinal nerve involvement may contribute.
1.4.2.19.1.9
1.4.2.19.2
Gray’s
Anatomy
1.4.2.19.2.1
Vertebral Muscles 1
1.4.2.19.2.2
Vertebral Muscles 2
1.4.2.19.3
Vertebral
Muscles
1.4.2.19.3.1 Splenius
1.4.2.19.3.1.1 Splenius Capitis
1.4.2.19.3.1.2 Splenius Cervicis
1.4.2.19.3.2 Erector Spinae (Sacrospinalis)
1.4.2.19.3.2.1 Introduction
1.4.2.19.3.2.1.1 These are the largest mass of muscles of the back and are grouped according to their relative position to the spine with the following arrangement medial to lateral spinalis, longissimus, and iliocostalis.
1.4.2.19.3.2.2 Iliocostalis (Lateral Group)
1.4.2.19.3.2.2.1 Iliocostalis Cervicis
1.4.2.19.3.2.2.2 Iliocostalis Lumborum
1.4.2.19.3.2.2.3 Iliocostalis Thoracis
1.4.2.19.3.2.3 Longissimus (Intermediate Group)
1.4.2.19.3.2.3.1 Longissimus Capitis
1.4.2.19.3.2.3.2 Longissimus Cervicis
1.4.2.19.3.2.3.3 Longissimus Thoracis
1.4.2.19.3.2.4 Spinalis (Medial Group)
1.4.2.19.3.2.4.1 Spinalis Capitis
1.4.2.19.3.2.4.2 Spinalis Cervicis
1.4.2.19.3.2.4.3 Spinalis Thoracis
1.4.2.19.3.3 Transversospinalis
1.4.2.19.3.3.1 Multifidus
1.4.2.19.3.3.2 Rotatores Brevis
1.4.2.19.3.3.3 Rotatores Longus
1.4.2.19.3.3.4 Semispinalis Capitis
1.4.2.19.3.3.5 Semispinalis Cervicis
1.4.2.19.3.3.6 Semispinalis Thoracis
1.4.2.19.3.4 Segmental
1.4.2.19.3.4.1 Interspinales B90E90
1.4.2.19.3.4.1.1 This muscle helps with spinal extension. The interspinales consists of pairs of small muscles between the spinous processes from C1 through T2 and L1 to the sacrum. This muscle is innervated by the dorsal rami of the spinal nerves.
1.4.2.19.3.4.2 Intertransversarii B91E91
1.4.2.19.3.4.2.1 This muscle acting unilaterally, helps with lateral flexion of the spine. The intertransversarii consists of pairs of small muscles anterior and posterior on both sides between the transverse processes from C1 to T1 and from T10 to L5. This muscle is innervated by the ventral and dorsal rami of the spinal nerves.
1.4.2.19.3.5 Scalene
1.4.2.19.3.5.1 Scalenus Anterior
1.4.2.19.3.5.2 Scalenus Medius
1.4.2.19.3.5.3 Scalenus Posterior
1.4.2.19.3.6 Sub Occipital
1.4.2.19.3.6.1 Obliquus Capitis Inferior
1.4.2.19.3.6.2 Obliquus Capitis Superior
1.4.2.19.3.6.3 Rectus Capitis Anterior
1.4.2.19.3.6.4 Rectus Capitis Lateralis
1.4.2.19.3.6.5 Rectus Capitis Posterior Major
1.4.2.19.3.6.6 Rectus Capitis Posterior Minor
1.4.2.19.3.7 Spinal Intrinsic
1.4.2.19.3.7.1 Longus Capitis
1.4.2.19.3.7.2 Longus Capitis Anterior
1.4.2.19.3.7.3 Longus Colli
1.4.2.19.3.7.4 Rectus Capitis Anterior
1.4.2.20 Thigh (Femur) *
Back Table
of Contents References
1.4.2.20.1 Introduction
1.4.2.20.1.1 These muscles serve three important functions
1.4.2.20.1.1.1 Stability
1.4.2.20.1.1.2 Locomotion
1.4.2.20.1.1.3 Maintenance of posture
1.4.2.20.1.2 Often these muscles cross two joints and act equally on both.
1.4.2.20.1.3 The upper extremity muscles, by contrast, are characterized by versatility of movement.
1.4.2.20.1.4 Most of these muscles, except the psoas, originate in the pelvic (hip) and insert on the femur.
1.4.2.20.1.5 The psoas major, Iliacus (Iliopsoas), and Gracilis are the only anterior muscles of this group.
1.4.2.20.1.6 The deep fascia, which encases the entire thigh, is called the fascia lata. It joins laterally with the tendons of the gluteus maximus and the tensor fasciae latae to form a thickened structure called the iliotibial tract. The iliotibial tract inserts into a lateral condyle of the tibia but has no action on the lower leg.
1.4.2.20.1.7 The medial adductor grouping includes the adductors, brevis, longus and magnus. The gracilis and pectineus are also included in this grouping.
1.4.2.20.1.8 The Gracilis is both an adductor and knee flexor. The Gracilis is included in both the thigh and leg muscle groupings.
1.4.2.20.1.9 The muscles of locomotion include; the leg flexors: iliopsoas and tensor fasciae latae; the leg extensors: gluteus maximus and the hip stabilizers: gluteus minimus and medius.
1.4.2.20.1.10 The posterior six deep lateral rotators which serve to stabilize the femur in its joint socket are: Gemellus inferior and superior; Obturator Externus and Internus; Piriformis; and Quadratus Femoris.
1.4.2.20.1.11 Although the muscles above can serve dual functions in multiple categories, their primary function served to establish the major groupings under which they would be listed.
1.4.2.20.2 Gray’s Anatomy
1.4.2.20.2.1 Thigh Muscles 1
1.4.2.20.2.2 Thigh Muscles 2
1.4.2.20.2.3
1.4.2.20.3 Thigh Muscles
Back Table of Contents References
1.4.2.20.3.1 Muscles of Locomotion
1.4.2.20.3.1.1 Gluteus Maximus
1.4.2.20.3.1.2 Gluteus Medius
1.4.2.20.3.1.3 Gluteus Minimus Ant & Post
1.4.2.20.3.1.4 Iliacus
1.4.2.20.3.1.5 Psoas Major
1.4.2.20.3.1.6 Psoas Minor
1.4.2.20.3.1.7 Tensor Fasciae Latae
1.4.2.20.3.2 Medial Adductor Compartment
1.4.2.20.3.2.1 Adductor Brevis B6E6
1.4.2.20.3.2.1.1 This muscle adducts, flexes, and medially rotates the hip (thigh). Its origin is on the pubic bone and it inserts onto the femur medially. Its nerves are the Obturator and nerve roots L2-L4.
1.4.2.20.3.2.2 Adductor Longus B8E8
1.4.2.20.3.2.2.1 This muscle adducts, extends, and medially rotates the hip (thigh). Its origin is on the pubic bone and it inserts onto the femur medially. Its nerves are the Obturator and nerve roots L2-L4.
1.4.2.20.3.2.3 Adductor Magnus B9E9
1.4.2.20.3.2.3.1 This muscle adducts, flexes, and medially rotates the hip (thigh). The origins of its anterior fibers are on the pubic bone and ramus of the ischium. The origins of its posterior fibers are on the Ischial tuberosity. This muscle inserts onto the femur medially and on the adductor tubercle on medial condyle of femur. The nerves of the posterior fibers are the tibial portion of sciatic and nerve roots L4-S1. The nerves of the anterior fibers are the Obturator and nerve roots L2-L4.
1.4.2.20.3.2.4 Gracilis
1.4.2.20.3.2.5 Pectineus
1.4.2.20.3.3 Posterior Six Deep Lateral Rotators
1.4.2.20.3.3.1 Gemellus Inferior
1.4.2.20.3.3.2 Gemellus Superior
1.4.2.20.3.3.3 Obturator Externus
1.4.2.20.3.3.4 Obturator Internus
1.4.2.20.3.3.5 Piriformis
1.4.2.20.3.3.6 Quadratus Femoris
1.4.2.21 Leg (Tibia and Fibula) *
Back Table of Contents References
1.4.2.21.1
Introduction
1.4.2.21.1.1
Most
of the muscles in this grouping act to flex or extend the leg (Tibia &
Fibula) although noted exceptions such as the hamstrings (thigh extension),
Rectus Femoris (thigh flexion), Sartorius (thigh flexion & lateral rotation)
and Gracilis (thigh adduction) act on the thigh as well. The muscles of this group are divided into
three categories namely; medial adductor compartment, anterior extensor
compartment, and posterior flexor compartment. The medial adductor compartment
includes the gracilis, which both adducts the thigh and flexes the leg. The
medial adductor compartment also includes muscles which act variously only on
the thigh and are included above under thigh Muscles (See Medial Adductor
Compartment above). The muscles of this grouping are innervated by the Obturator
nerve. The Anterior Extensor Compartment includes the quadriceps femoris and
the sartorius. The Quadriceps femoris muscle is a composite muscle, which
includes four muscles as listed below. All of the muscles of this grouping are innervated by the femoral
nerve. The posterior flexor compartment includes the hamstrings, which is also
a composite muscle (see below). These muscles are innervated by the tibial nerve (branch of
sciatic). The hamstrings are so named
because they feel like strings especially in the popliteal fossa, which is a
diamond-shaped area in the back of the knee bordered by the semitendinousus and
semimembranosus medially and the biceps femoris laterally.
1.4.2.21.2
Gray’s
Anatomy
1.4.2.21.2.1 Thigh Muscles 1
1.4.2.21.2.2 Thigh Muscles 2
1.4.2.21.2.3
Leg Muscles 1
1.4.2.21.3 Medial Adductor Compartment (See also Medial Adductor Compartment Thigh)
1.4.2.21.3.1 Gracilis
1.4.2.21.4 Leg Anterior Extensor Compartment
1.4.2.21.4.1 Quadriceps Femoris
1.4.2.21.4.1.1
Rectus Femoris
1.4.2.21.4.1.2
Sartorius
1.4.2.21.4.1.3
Vastus
Intermedius
1.4.2.21.4.1.4
Vastus
Lateralis
1.4.2.21.4.1.5
Vastus Medialis
1.4.2.21.5 Leg Posterior Flexor Compartment
1.4.2.21.5.1 Hamstrings
1.4.2.21.5.1.1
Biceps Femoris
B13E13
1.4.2.21.5.1.1.1
The long and
short head of the biceps femoris together flex and laterally rotate the knee (leg)
(tibia and fibula). Alone the long head extends, adducts, and laterally rotates
the hip (thigh). The long head of the
biceps femoris attaches (origin) to the Ischial tuberosity and
sacrotuberous ligament. The short head
has its origin on the femur. Both heads insert onto the tibia and fibula. The
nerve supply of the long head is the Sciatic (Tibial Portion)
and its nerve roots are L5-S2. The
nerve supply of the short head is the Sciatic (Common peroneal
portion) and its nerve roots are L5-S2.
1.4.2.21.5.1.2
Semimembranosus
1.4.2.21.5.1.3
Semitendinosus
1.4.2.22 Foot and Toes
Back Table of Contents References
1.4.2.22.1
Introduction
1.4.2.22.1.1
1.4.2.22.2
Gray’s
Anatomy
1.4.2.22.2.1
Leg Muscles 1
1.4.2.22.2.2
Ankle Anatomy 1
1.4.2.22.3 Anterior Compartment
1.4.2.22.3.1 Extensor Digitorum Longus
1.4.2.22.3.2 Extensor Hallucis Longus
1.4.2.22.3.3 Peroneus Tertius
1.4.2.22.3.4 Tibialis Anterior
1.4.2.22.4 Lateral Peroneal Compartment
1.4.2.22.4.1 Peroneus Brevis
1.4.2.22.4.2 Peroneus Longus
1.4.2.22.5 Posterior Superficial Compartment
1.4.2.22.5.1 Gastrocnemius
1.4.2.22.5.2 Plantaris
1.4.2.22.5.3 Soleus
1.4.2.22.6 Posterior Deep Compartment
1.4.2.22.6.1 Flexor Digitorum Longus
1.4.2.22.6.2 Flexor Hallucis Longus
1.4.2.22.6.3 Popliteus
1.4.2.22.6.4 Tibialis Posterior
1.4.2.23 Foot-Intrinsic *
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1.4.2.23.1
Introduction
1.4.2.23.1.1
The
intrinsic muscles of the foot are similar to the hand muscles, which are
specialized for intricate and precise movements where as the foot muscles are
specialized for support and locomotion. The deep facia of the foot forms the
plantar aponeurosis (fascia) that attaches to the calcaneus and the phalanges
providing longitudinal arch support. The intrinsic foot muscles are divided
into two groups; Dorsal, which includes only one muscle (see below) and the plantar muscles, which
include several layers as, outlined below.
1.4.2.23.2
Gray’s
Anatomy
1.4.2.23.2.1
Intrinsic Foot Muscles
1.4.2.23.3 Dorsal Muscles
1.4.2.23.3.1 Extensor Digitorum Brevis
1.4.2.23.3.2 Extensor Hallucis Brevis
1.4.2.23.4 Plantar Muscles
1.4.2.23.4.1 Plantar First Superficial Layer
1.4.2.23.4.1.1 Abductor Digiti Minimi (Foot) B1E1
1.4.2.23.4.1.1.1 The action of this muscle is to abduct the fifth toe away from the fourth toe. This muscle has its origin on the calcaneus and it inserts onto the little toe. It is supplied by the lateral plantar nerve with nerve roots of S2 and S3.
1.4.2.23.4.1.2 Abductor Hallucis B3E3
1.4.2.23.4.1.2.1 The action of this muscle is to abduct the big toe from the mid line of the foot. This muscle has its origin on the calcaneus and it inserts onto the big toe. It is supplied by the medial plantar nerve with nerve roots of S2 and S3.
1.4.2.23.4.1.3 Flexor Digitorum Brevis
1.4.2.23.4.1.4 Sectional Questions
1.4.2.23.4.1.4.1 Questions
1.4.2.23.4.2 Plantar Second Layer
1.4.2.23.4.2.1 Lumbricals
1.4.2.23.4.2.2 Quadratus Plantae
1.4.2.23.4.3 Plantar Third Layer
1.4.2.23.4.3.1 Adductor Hallucis B7E7
1.4.2.23.4.3.1.1 The adductor hallucis adducts the big toe towards the 2nd toe and Flexes the big toe towards plantar surface. The oblique head attaches (origin) to the bases of the 2nd, 3rd and 4th metatarsals. The transverse head attaches (origin) to the Plantar Metatarsophalangeal ligaments of the 3rd, 4th and 5th toes. Both heads insert into the lateral side of base of proximal phalanx of big toe. This muscle is supplied by the lateral plantar nerve and its nerve roots are S2 and S3.
1.4.2.23.4.3.2 Flexor Digiti Minimi Brevis
1.4.2.23.4.3.3 Flexor Hallucis Brevis
1.4.2.23.4.4 Plantar Fourth Deep Layer
1.4.2.23.4.4.1 Dorsal Interossei
1.4.2.23.4.4.2 Plantar Interossei
1.4.3
Individual
Muscles
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