Lateral pterygoid muscle.MUSCULISPTERYGOIDEUSLATERALIS.

Begins: from the infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone, from the tendon of the deep layer of the temporal muscle, from the outer surface of the pterygoid process of the sphenoid bone.

Attached: to the pterygoid fossa of the condylar process of the mandible, to the articular capsule and disc of the temporomandibular joint.

Function: with unilateral contraction, it shifts the lower jaw in the direction opposite to the contracted muscle; with bilateral contraction, it moves it forward. IT DOES NOT LIFT THE LOWER JAW AS IT GOES STRICTLY HORIZONTALLY!

Medial pterygoid muscle.MUSCULIS PTETZGOIDEUS MEDIALIS.

Begins: from the walls of the pterygoid fossa of the pterygoid processes of the sphenoid bone, the outer surface of the pyramidal process of the palatine bone.

Attached: to the pterygoid tuberosity on the inner surface of the angle of the lower jaw.

Function: with unilateral contraction, it shifts the lower jaw in the direction opposite to the contracted muscle; with bilateral contraction, it lifts and pushes it forward.

QUESTION for everyone.

Muscles that lower the mandible:

Dropping of the lower jaw carried out by contraction of the muscles of the floor of the mouth with the hyoid bone fixed:

Mylohyoid muscle (m. mylohyoideus);

Geniohyoid muscle (m. geniohyoideus);

Anterior belly of the digastric muscle (venter anterior m. digastrici).

THUS:

Movement of the lower jaw	Muscle contraction
Down (mouth opening).	Bilateral reduction m. mylohyoideus, m. geniohyoideus, venter anterior m. digastrici.
Up (teeth closing).	Bilateral reduction m. masseter, m. temporalis, m. pterygoideus medialis.
	Bilateral reduction m. pterygoideus medialis, m. pterygoideus lateralis, surface layer m. masseter.
	Bilateral contraction of the posterior bundles m. temporalis.
	Reduction m. pterygoideus lateralis left side and back bundles m. temporalis right side.
	Reduction m. pterygoideus lateralis right side and back bundles m. temporalis left side.

Temporal- mandibularjoint. ARTICULATIO TEMPORO-MANDIBULARIS.

Question 4. The structure of the temporomandibular joint.

Educated articular head lower jaw and mandibular fossa With articular tubercle temporal bone.

The incongruity between the head and the fossa is leveled due to articular disc and attachments joint capsules to the temporal bone. The articular disc has the shape of a biconcave lens and consists of fibrous cartilage tissue. It divides the joint cavity into two isolated chambers: upper and lower joint spaces. The function of the articular disc is to equalize the discrepancy between the fossa and the head, as well as to soften chewing impacts.

Ligamentous apparatus The temporomandibular joint is represented by two groups of ligaments:

intracapsular ligaments– anterior and posterior discotemporal, lateral and medial discomandibular;

extracapsular ligaments– lateral, sphenomandibular and stylomandibular.

Articular ligaments prevent stretching of the joint capsule and limit excessive movements of the lower jaw.

With closed dentition, the articular head is located at the base of the slope of the articular tubercle. When the lower jaw moves, the articular head makes excursions along the slope of the articular tubercle, while chewing pressure is transmitted through the articular disc to the articular tubercle. In the upper part of the joint, mainly translational movements of the articular head and sliding of the disc along the slope of the articular tubercle occur. In the lower section, rotational movements of the articular head take place around the horizontal axis.

The quadriceps is made up of 4 different muscles that work together. That is why they have a common name. When performing squats with a barbell, the quadriceps works longitudinally. As a result, the legs in the lateral projection become wider. Along with the side projection, there is also a frontal one, which should also have a decent appearance. How to achieve this? You need to pump up the adductor muscles, which are located on the inner surface of the thighs. According to physiology, these muscles account for up to 30% of the total volume of leg muscles.

However, there is one more subtlety here - the lateral muscle, which is part of the quadriceps, is shifted outward from the central axis of the thigh. The development of this muscle forms the so-called “breeches”, visually increasing the volume of the leg. It turns out that you just need to pump up this muscle? That's right, all that remains is to choose the right exercise for this.

In general, there are two best exercises for pumping up the quadriceps:

• Lunges;

Which of these exercises will allow you to pump up your riding breeches? Let's figure it out.

Hack squats

When performing this exercise, the buttocks are actively involved in the work, which work together with the lateral muscle. Their work is identical to the work of the back and biceps or the chest and triceps. That is, the lateral muscle receives a good share of the load. However, standard hack squats are not suitable here. To engage the lateral muscles, you need to slightly change the exercise technique - place your feet at a distance of 20 cm from each other.

Lunges with a barbell

This exercise also involves the buttocks, but they are helped by the adductor muscles of the inner thigh. At the same time, the wide lateral ones are almost completely freed from the load. This exercise is not suitable for us.

Video on the topic: "Performing hack squats in the machine"

Lateral pterygoid muscle triangular in shape, lies deep in the infratemporal fossa and is closed in front by the zygomatic arch. Begins muscularly with two heads: top and bottom .

Upper head beret Start from the infratemporal surface and the infratemporal crest, the greater wing of the pterygoid bone and from the tendon of the deep layer of the temporal muscle, goes back and laterally and, connecting with the lower head, attached short tendons to the articular capsule and articular disc of the temporomandibular joint.

Bottom head departs from the outer surface of the pterygoid process of the sphenoid bone and attached to the pterygoid fossa of the condylar process of the mandible. The buccal nerve passes through the gap between the upper and lower heads.

Function: moves the lower jaw in the direction opposite to the contracted muscle, with bilateral contraction pushes it forward.

Medial pterygoid muscle quadrangular in shape, located deep on the inner surface of the lower jaw. Its fibers run parallel to the masseter muscle. Begins tendon and muscle bundles from the walls of the pterygoid fossa of the pterygoid processes of the main bone, the outer surface of the pyramidal process of the palatine bone, goes back, down and laterally, attaching to the pterygoid tuberosity, symmetrically with the masseter muscle.

Function: with unilateral contraction moves the lower jaw to the opposite side, with bilateral picks her up And pushes forward.

Scheme VIII (separate)

So, all chewing muscles produce movement in the temporomandibular joint. During the act of chewing, the movements of the lower jaw in humans are characterized by great diversity, which is not found in other representatives of mammals.

This diversity stems from the structural features of the temporomandibular joint and the position of the masticatory muscles. Thus, in predators only closing and opening of the jaws (up and down) is possible, in ruminants only lateral movements (right - left), and in rodents sliding movements of the jaws (forward - backward). In humans, all these movements are combined. Their combination helps to carry out the main function - grinding food. In this case, the lower jaw, together with the teeth, makes an almost complete circle. Therefore, the human chewing mechanism is universal, and not specialized, like in animals.

Thus, the chewing muscles in humans produce the following movements:

1. Raise the lower jaw up , i.e. close the mouth (temporalis muscle, masseter proper and internal pterygoid).

2. Move the lower jaw back (temporalis muscle).

3. Moves the jaw forward (masseter and both pterygoid muscles).

4. Moves the jaw sideways (left external pterygoid muscle - to the right side, and right - to the left side).

Front the scalene muscle, with bilateral contraction, tilts the cervical spine forward, and with unilateral contraction, it tilts to its side. When the spine is in a fixed position, the muscle raises the first rib. The muscle begins from the anterior tubercles of the III–VI cervical vertebrae, and the site of its attachment is the tubercle of the anterior scalene muscle of the 1st rib.

Average When the scalene muscle contracts, it tilts the neck forward, and when the neck is in a fixed position, it raises the first rib. The origin of the muscle is located on the anterior tubercle of the six lower cervical vertebrae, and the attachment point is on the upper surface of the first rib.

Rear the scalene muscle lifts the second rib and, with the chest in a fixed position, bends the cervical spine forward. The muscle begins on the posterior tubercles of the IV–VI cervical vertebrae and attaches to the outer surface of the II rib.

A group of muscles located under the hyoid bone (middle neck muscles)

The thyrohyoid muscle, when contracted, brings the larynx and hyoid bone closer together, and when the hyoid bone is in a fixed position, it raises the larynx. The origin of the muscle is on the oblique line of the thyroid cartilage, and the insertion point is on the body of the hyoid bone.

The omohyoid muscle expands the lumen of the internal jugular vein. When the scapula is in a fixed position, it moves the hyoid bone down and outward and pulls back the sheath of the neurovascular bundle of the cervical bundle. This thin and long muscle has a superior belly and an inferior belly, which are connected to each other by the intermediate tendon. The upper abdomen begins at the lower edge of the hyoid bone, the upper - on the upper transverse ligament and the upper edge of the scapula. Connecting to each other, both bellies are attached to the tendon jumper.

The sternohyoid muscle moves the hyoid bone downward. The muscle begins on the posterior surface of the clavicle, the manubrium of the sternum and the capsule of the sternoclavicular joint, and is attached to the lower edge of the body of the hyoid bone.

The sternothyroid muscle moves the larynx downward. The origin of the muscle is located on the posterior surface of the manubrium of the sternum and the cartilage of the 1st rib, the attachment point is on the oblique line of the thyroid cartilage of the larynx.

A group of muscles located above the hyoid bone (middle neck muscles)

The digastric muscle, contracting, lowers the lower jaw and pulls it back. When the lower jaw is in a fixed position, this muscle raises the hyoid bone.

The muscle is so named because it is divided into an anterior belly and a posterior belly, which are connected to each other by a tendon bridge. The anterior abdomen begins in the digastric fossa of the lower jaw; The posterior abdomen has its origin at the mastoid notch of the temporal bone. Both bellies are attached to the body of the hyoid bone, passing into the tendon.

The stylohyoid muscle lifts the hyoid bone, simultaneously moving it backward and outward. This thin fusiform muscle originates at the base of the styloid process of the temporal bone and inserts into the body and greater cornu of the hyoid bone.

The mylohyoid muscle raises the hyoid bone and, when in a fixed position, lowers the lower jaw.

The muscle itself is flat; connecting with the mylohyoid muscle of the opposite side, it forms the diaphragm of the mouth, or the floor of the mouth. The starting point is the mylohyoid line of the lower jaw. The attachment point of the main part of the muscle is located in the area of ​​the oral diaphragm, connecting with the fibers of the main part of the opposite mylohyoid muscle and forming the mylohyoid suture of the oral diaphragm. The attachment point of the posterior muscle bundles is on the anterior side of the hyoid bone.

The geniohyoid muscle lifts the hyoid bone, moving it forward, and when the hyoid bone is in a fixed position, it lowers the lower jaw. The muscle is located above the mylohyoid muscle, begins at the mental axis of the lower jaw and is attached to the anterior surface of the body of the hyoid bone.

Fascia of the neck

The fascia of the neck consists of three plates and has a complex structure due to the large number of muscles and organs. The space between the fascia of the neck and the organs of the neck is filled with fatty tissue and loose connective tissue.

The superficial plate is a continuation of the fascia of the chest and back. It forms a vagina for the submandibular gland and for the suprahyoid and sternocleidomastoid muscles of the neck. In the back of the neck, the fascia envelops the trapezius muscle, reaching the occipital protuberance and the superior nuchal line. The suprasternal interaponeurotic space is formed above the jugular notch of the manubrium of the sternum.

The prevertebral plate begins at the base of the skull, descends, covers the prevertebral muscles of the neck, and also passes to the scalene muscles. Between the prevertebral plate and the organs of the neck is the retrovisceral space.

The pretracheal plate begins in the region of the clavicle and manubrium of the sternum and forms a sheath for the infrahyoid muscles. Between the pretracheal plate and the organs of the neck is the previsceral space.

32. Facial muscles: topography, structure, functions, blood supply, innervation.

In the process of contraction of facial muscles, certain areas of the skin are displaced and facial expression changes. Facial muscles also reduce or enlarge the natural openings of the face: mouth, eyes, nostrils.

Each muscle or muscle group performs its own functions.

Occipitofrontal muscle is divided into two parts: the occipital abdomen and the frontal abdomen.

Contracting, the occipital belly moves the scalp along with the tendon helmet, which is a dense plate of tendons located under the scalp, back to the back of the head, and the frontal belly forms transverse folds on the forehead, simultaneously raising the eyebrows and widening the palpebral fissures. The occipital belly has its origin at the superior nuchal line of the occipital bone, and is attached in the posterior part of the tendon helmet. The frontal belly begins in the area of ​​the tendon helmet and is attached to the skin of the eyebrows.

Muscle that wrinkles the eyebrow, when contracted, moves the eyebrows down and slightly inward, towards the bridge of the nose. In this case, two deep longitudinal folds are formed above the bridge of the nose, running from the eyebrows upward. The origin of the muscle is located on the frontal bone above the lacrimal bone, and the attachment point is in the skin of the eyebrows.

Orbicularis oculi muscle consists of three parts: orbital, lacrimal and eyelid.

When the orbital part of the muscle contracts, the transverse folds of the forehead are smoothed, the eyebrows are lowered and the palpebral fissure narrows.

When the eyelid part of the muscle contracts, the palpebral fissure closes completely.

Lacrimal part, contracting, expands the lacrimal sac. When united, all three parts of the muscle are arranged in an ellipse. The starting point of all parts is on the bones in the area of ​​the medial corner of the eye.

Orbital part forms a muscular ring, located along the lower and upper edges of the orbit, the lacrimal part goes around the lacrimal sac, covering it in front and behind, and the age-old part lies in the skin of the eyelids.

Ear muscles include three muscles: anterior, posterior and superior.

The anterior and superior muscles are covered by the temporal fascia. These muscles are practically not developed in humans. When they contract, the auricle moves slightly forward, backward and upward. The point of origin of the ear muscles is the tendon helmet, and the attachment point is the skin of the auricle.

Nasalis muscle is divided into two parts: wing and transverse. This muscle is also poorly developed. When the alar part contracts, the wing of the nose lowers; when the transverse part contracts, the nasal opening narrows. The origin of the muscle lies on the upper jaw in the area of ​​the alveoli of the incisor and canine.

Mounting location wing part of the muscle located on the skin of the wing of the nose, and the transverse part - on the back of the nose, where it connects with the opposite muscle.

In the cheekbone area, the zygomaticus minor and zygomaticus major muscles are distinguished. Both muscles move the corners of the mouth up and to the sides. The point of origin of the muscles is located on the lateral and temporal surface of the zygomatic bone; at the point of attachment, the muscles intertwine with the orbicularis oris muscle and grow into the skin of the corner of the mouth.

Buccal muscle when contracting, it pulls the corners of the mouth back and also presses the lips and cheeks against the teeth. This muscle is the basis of the cheeks. The muscle begins on the outer surface of the upper and lower jaw in the area of ​​the alveoli, at the pterygomandibular suture, and is attached to the skin of the lips and corners of the mouth, intertwined with the muscles of the upper and lower lips.

Laughter muscle fickle, its task is to stretch the corners of the mouth to the sides. The point of origin is located in the skin near the nasolabial fold and chewing fascia, and the point of attachment is in the skin of the corners of the mouth.

Orbicularis oris muscle are muscle bundles located in circles in the thickness of the lips. When the orbicularis muscle contracts, the mouth closes and the lips extend forward. The origin point is located in the skin of the corner of the mouth, and the attachment point is in the skin in the midline area.

The levator labii superioris muscle contracts to lift the upper lip and make the nasolabial fold deeper. The muscle begins at the infraorbital margin of the upper jaw and attaches to the skin of the nasolabial fold.

Levator anguli oris muscle together with the zygomatic muscles, it moves the corners of the lips upward and to the sides. The starting point is in the canine fossa of the upper jaw, and the attachment point is in the skin of the corner of the mouth.

Depressor anguli oris muscle, when contracting, moves the corners of the mouth down and to the sides. The origin of the muscle is located on the anterior surface of the lower jaw under the mental foramen. The place of attachment of individual bundles is located in the thickness of the upper lip, the rest are woven into the skin of the corner of the mouth.

Depressor labii muscle, pulls the lower lip down. This muscle is covered by the depressor anguli oris muscle; the starting point is the anterior surface of the lower jaw in front of the mental foramen, and the attachment point is the skin of the chin and lower lip.

Mentalis muscle when contracted, it pulls the skin of the chin upward, forming dimples. The muscle is partially covered by the depressor labii labii muscle; begins on the alveolar elevations of the incisors of the lower jaw and is attached to the skin of the chin.

33. Chewing muscles: topography, structure, functions, blood supply, innervation.

Thanks to the masticatory muscles, the chewing process is carried out as a result of the displacement of the lower jaw during their contraction.

The temporalis muscle lifts the lower jaw, while the posterior muscle bundles move it backward, and the anterior ones - forward and upward. The muscle begins on the temporal surface of the greater wing of the sphenoid bone and the squamous part of the temporal bone, and is attached to the apex and medial surface of the coronoid process of the mandible.

Chewing muscles:

1 - temporal fascia:

a) superficial plate, b) deep plate;

2 - chewing muscle:

a) deep part, b) superficial part

The masseter muscle raises the lower jaw. It has the shape of an irregular rectangle and consists of a superficial part and a deep part. The starting point of the superficial part is the anterior and middle parts of the zygomatic arch, and the deep part is the middle and posterior parts of the zygomatic arch. Both parts of the muscle are attached to the lateral side of the ramus of the mandible along its entire length and to the angle of the jaw.

The lateral pterygoid muscle performs two functions: with bilateral contraction (simultaneous contraction of both muscles), it pushes the lower jaw forward, and with unilateral contraction, it moves it sideways, in the opposite direction (to the side opposite the contracting muscle).

It is located in the inferotemporal fossa. The origin point is the temporal surface of the greater wing of the sphenoid bone, the lateral plate of the pterygoid process and the infratemporal crest, and the attachment point is the medial surface of the articular capsule of the temporomandibular joint, the articular process of the mandible and the articular disc.

Chewing muscles (inside view):

1 - lateral pterygoid muscle;

2 - chewing muscle;

3 - medial pterygoid muscle

The medial pterygoid muscle, like the lateral muscle, with bilateral contraction pushes the lower jaw forward, simultaneously lifting it, and with unilateral contraction it moves it to the opposite side.

The muscle begins in the pterygoid fossa of the sphenoid bone and is attached to the inner surface of the lower jaw.

34. Muscles and fascia of the upper limb girdle: topography, structure, functions, blood supply, innervation.

Deltoid moves the shoulder outward to a horizontal plane, while the front muscle bundles pull the arm forward, and the rear ones - back. It is a thick, triangular-shaped muscle that covers the shoulder joint and parts of the shoulder muscles. Its large bunches fan-shapedly converge to the apex of the triangle, directed downward. The muscle starts from the axis of the scapula, acromion and lateral part of the clavicle, and is attached to the deltoid tuberosity of the humerus. Under the lower surface of the muscle is the subdeltoid bursa.

Supraspinatus muscle It has a triangular shape and lies in the supraspinatus fossa of the scapula, located directly under the trapezius muscle. The supraspinatus muscle lifts the shoulder and retracts the capsule of the shoulder joint, preventing it from pinching. The origin of the muscle is on the surface of the supraspinatus fossa, and the attachment point is on the upper platform of the greater tubercle of the humerus and on the posterior surface of the capsule of the shoulder joint.

Infraspinatus muscle turns the shoulder outward, moves the raised arm back and retracts the capsule of the shoulder joint. This is a flat, triangular-shaped muscle that fills the entire infraspinatus fossa. Its upper part is covered by the trapezius and deltoid muscles, and the lower part by the latissimus dorsi and teres major muscles.

The infraspinatus muscle starts from the wall of the infraspinatus fossa and the posterior surface of the scapula, and is attached to the middle platform of the greater tubercle of the humerus and the capsule of the shoulder joint. At the site of its attachment to the humerus is the subtendinous bursa of the infraspinatus muscle.

Teres minor muscle turns the shoulder outward, at the same time slightly moving it back, and retracts the capsule of the shoulder joint.

An oblong, rounded muscle, the upper part of which is adjacent to the infraspinatus muscle, the anterior part is covered by the deltoid muscle, and the posterior part is covered by the teres major muscle. The point of origin is located on the posterior surface of the scapula below the infraspinatus muscle, and the attachment point is on the lower platform of the greater tuberosity of the humerus and the posterior surface of the capsule of the shoulder joint.

Teres major muscle turns the shoulder inward and pulls it back, bringing the arm towards the body. An oblong flat muscle adjacent to the latissimus dorsi muscle and partially covered by it in the posterior section. In the outer section, the teres major muscle is covered by the deltoid muscle. The starting point is the posterior surface of the scapula at its lower angle, the attachment point is the crest of the lesser tubercle of the humerus. Near the attachment site is the subtendinous bursa of the teres major muscle.

Subscapularis muscle in extends the shoulder inward and takes part in its adduction to the body. A flat, triangular-shaped vastus muscle that fills the entire subscapularis fossa. It begins on the surface of the subscapularis fossa and ends on the lesser tubercle of the humerus and on the anterior surface of the capsule of the shoulder joint.

At the attachment site there is a small subtendinous bursa of the subscapularis muscle.

Fascia of the upper limbs

The subcutaneous fascia of the upper limb is poorly expressed. The fascia itself varies in thickness throughout its entire length; its individual plates are highly developed and form sheaths for muscles and tendons, lining pits and canals. Depending on the muscle groups covered, the fascia of the shoulder girdle, the fascia of the shoulder, the fascia of the forearm and the fascia of the hand are distinguished.

The thigh muscles are the largest muscles in the human body. The overall physical shape of the athlete, his weight, strength indicators in various movements, and metabolic rate depend on their strength and mass. The influence of well-developed thigh muscles on the health of the genitourinary system, hip and knee joints is also undeniable. Therefore, it makes sense to thoroughly understand the structure and functions of the thigh muscles. This will give you a deeper understanding of the essence of the exercises performed in the gym.

Quadriceps femoris

As the name suggests, the muscle consists of four parts (bundles), and is also called the quadriceps. Many people may be missing one of the muscles (anatomical variation).

The main function of all parts of the quadriceps muscle is to extend the leg at the knee and flex the hip (bringing the thigh closer to the abdomen).

Vastus lateralis muscle (m. vastus lateralis)

The largest of all the muscles of the thighs. A flat, unipennate muscle that determines the roundness of the lateral part of the thigh.

It is located on the lateral surface of the thigh and extends to the front of the thigh in the knee area. The upper end is attached to the femur in the area of ​​the hip joint. Bottom - to the patella and tibia (tibia).
The top is covered by the fascia lata (a long, flat tendon on the side of the thigh that connects the muscles of the pelvis and lower leg).

The main function of the vastus lateralis muscle is:

extends the lower leg (extends the leg at the knee)

Quadriceps femoris is involved in exercises such as running, jumping, squats, lunges and in general in all movements in which the leg extends at the knee.

Vastus medialis (m. vastus medialis)

A thick, flat muscle located on the inside of the thigh, extending onto the front of the thigh near the knee. This muscle forms a rounded ridge on the inside of the knee, especially noticeable when you are sitting.

With its upper end, the muscle is attached along the entire length (from the inside) of the femur, and with its lower end it forms the suspensory ligament of the patella.

The main function of the vastus medialis muscle is:

Extends the lower leg (extension of the leg at the knee)

M. vastus medialis is involved in exercises such as running, jumping, squats, lunges and in general in all movements in which the leg extends at the knee.

Vastus intermedius muscle (m. vastus intermedius)

It is a flat lamellar muscle located between the vastus lateralis and vastus medialis. It is hidden under their edges and covered on top by the rectus femoris muscle (see below).

The upper end of the muscle is attached to the femur in the area of ​​the hip joint, and the lower end participates in the formation of the patellar ligament.

The main function of the vastus intermedius muscle is:

Extends the lower leg (extends the leg at the knee)

M. vastus intermedius is involved in exercises such as running, jumping, squats, lunges and in general in all movements in which the leg extends at the knee.

Rectus femoris (m. rectus femoris)

A long fusiform muscle located on the front of the thigh above all the other quadriceps muscles. With its upper end, the muscle is attached to the pelvic bone (lower anterior iliac spine above the acetabulum), and with its lower end it participates in the formation of the knee ligament.
This muscle is remarkable in that it is not attached to the femur. It is clearly visible on the front surface of the thigh, determining its roundness.

The main functions of the rectus femoris muscle:

Hip flexion (pulling the thigh toward the abdomen)

Shin extension (leg extension at the knee)

M. rectus femoris is involved in movements such as running, jumping, maintaining body balance, squats, and pulling the legs towards the body. Actively works in conjunction with the abdominal muscles when performing exercises for its development. It is an integral part.

Sartorius muscle (m. sartorius)

This is a narrow ribbon-shaped muscle up to 50 cm long. It runs diagonally from the outer part of the hip joint to the inner part of the knee joint. The muscle sits on top of other muscles on the front of the thigh and is clearly visible when there is low subcutaneous fat.

The upper end of the muscle is attached to the bones of the pelvis (superior anterior iliac spine of the ilium), and the lower end is attached to the tibia (shin). It is curious that this muscle is not involved in extending the leg at the knee, although it belongs to the quadriceps.

The main functions of the sartorius muscle:

Hip flexion (pulling the hip towards the body)

Abduction and external rotation of the hip

M. Sartorius is involved in movements such as running, walking, bending the legs at the knees, pulling the hips towards the body, and rotating the hips. Therefore, by performing exercises in which weight is overcome by bending the leg at the knee, as well as by flexing the hip (pulling it towards the body), you also develop this muscle.

Collectively, these muscles are called the biceps femoris. These muscles determine the shape of the back of the thigh, its roundness. They also partly influence the filling of the space between the thighs.

Biceps femoris (m. biceps femoris)

A long, spindle-shaped muscle that runs along the entire back of the thigh. It consists, as the name suggests, of two heads: long and short. The long head is attached at the upper end to the ischial tuberosity of the pelvic bone, and at the lower end to the tibia (tibia). The short upper part is attached to the back surface of the femur, and the lower part is attached to the tibia.

The main functions of the biceps femoris muscle:

Shin flexion (leg bending at the knee)

Hip extension (moving the hip back or straightening the torso from a tilted position)

Maintaining body balance

M. biceps femoris is actively involved in bending the legs, in all movements in which the hip needs to be pulled back, and in extending the body from a tilted position.

Lack of flexibility and strength in the hamstrings is often the cause of back pain, poor posture, and problems with the knee joints.

Semitendinosus muscle (m. semitendinosus)

A long, flat, tapering muscle lying medial (closer to the middle of the body) in relation to the biceps femoris muscle. The upper part of the muscle is attached to the ischial tuberosity of the pelvic bone. The lower one is to the tibia (lower leg).

The main functions of the semitendinosus muscle:

Shin flexion (leg bending at the knee)

M. semitendinosus is actively involved in leg flexion, in all movements in which the hip is required to be pulled back, and in extension of the body from a tilted position.

Semimembranosus muscle (m. semimembranosus)

A long, flat muscle located in the posterior inner part of the thigh. The upper end is attached to the ischial tuberosity of the pelvic bone. The lower end - to various parts of the tibia and fascia of the lower leg muscles.

The main functions of the semimembranosus muscle:

Hip extension (moving it back or straightening the body from a tilted position)

Shin flexion (leg bending at the knee)

M. semimembranosus is actively involved in leg flexion, in all movements in which the hip is required to be pulled back, and in extension of the body from a tilted position.

Muscles of the inner thigh

These muscles are generally called adductors. Their main function is to bring the femur inward.

Thin muscle (m. gracilis)

A long, ribbon-shaped muscle located on top of all other muscles on the inside of the thigh. Its upper part is attached to the pubic bone, and its lower part is attached to the tibia (shin bone).

Main functions of the gracilis muscle:

Shin flexion (bends the leg at the knee)

Rotate the shin inward

M. gracilis is actively involved in all leg movements: running, walking, squatting, maintaining body balance.

Pectineus muscle (m. pectineus)

A flat muscle, attached at the upper end to the pubic bone, and at the lower end to the inner part of the middle of the femur.

Main functions of the pectineus muscle:

Hip adduction (pulls it inward)

Hip flexion (pulls the hip towards the body)

M. pectineus is actively involved in all leg movements: running, walking, squatting, maintaining body balance.

Long adductor muscle (m. adductor longus)

Flat thick muscle. The upper end is attached to the pubic bone, and the lower end to the inner part of the middle of the femur.

The main functions of the adductor longus muscle:

Hip adduction (pulls it inward)

External hip rotation

M. adductor longus is actively involved in all leg movements: running, walking, squats, maintaining body balance.

Short adductor muscle (m. adductor brevis)

A flat muscle that expands downwards. Attached at the upper end to the outer surface of the body and pubic bone. The lower (wide end) – to the inner part of the femur.

The main functions of the adductor brevis muscle:

Hip adduction (pulls it inward)

Hip flexion (pulls the hip toward the body, moving it forward)

M. adductor brevis is actively involved in all leg movements: running, walking, squats, maintaining body balance.

Large adductor muscle (m. adductor magnus)

The largest of the adductor muscles, its volume determines the degree to which the space between the thighs is filled. The picture shows the rear view.

Its upper end is attached to the ischial tuberosity of the pelvis and pubic bone. The lower (very widened end) is attached to the inner part of the femur almost along its entire length.

The main functions of the adductor magnus muscle:

Hip adduction (pulls it inward)

Rotates the hip outward

Internal bundles are involved in hip extension (pulling it back and straightening the body from a tilted position)

M. adductor magnus is actively involved in all leg movements: running, walking, squatting, maintaining body balance.

Muscles of the outer thigh

Tensor fascia latae (m. tensor fascia latae)

In general, this is the only muscle, with the exception of the buttock muscles, that is involved in hip abduction.

This is a flat, elongated muscle, tapering downward. The upper end is attached to the anterior iliac spine, and the lower end of this muscle passes into the fascia lata of the thigh - a long tendon that stretches to the lower leg. Being well developed, it gives a pleasant roundness to the lateral surfaces in the pelvic area.

The main functions of the tensor fascia lata are:

Tension of the fascia lata of the thigh (which is necessary for normal leg function when walking and running)

Strengthening the knee joint by stretching the fascia lata

Hip flexion

M. tensor fascia latae is actively involved when walking, running, and performing exercises on one leg.

Well, one last thing worth saying. that the muscles of the thighs and the muscles of the buttocks are interconnected anatomically and according to the functions they perform. A person is characterized by movements in which these muscles work in conjunction: walking, running, squats, bending. As a rule, exercises for developing legs also perfectly develop the buttocks.