UPPER BODY EXERCISES
Trunk or torso is an anatomical term for the central part of the body from which extend the neck and limbs.The trunk includes the thorax and abdomen.
Major muscle groups
The trunk also harbours many of the main groups of muscles in the body, including the:
Pectoral muscles
Abdominal muscles
Lateral Muscle (latissimus dorsi)
Arm Bicep
Arm Tricep
Shoulder Muscle (deltoid)
Pectoralis Major
The pectoralis major is a thick, fan-shaped muscle, situated at the chest (anterior) of the human body. It makes up the bulk of the chest muscles in the male and lies under the breast in the female. Underneath the pectoralis major is the pectoralis minor, a thin, triangular muscle.It arises from the anterior surface of the sternal half of the clavicle; from breadth of the half of the anterior surface of the sternum, as low down as the attachment of the cartilage of the sixth or seventh rib; from the cartilages of all the true ribs, with the exception, frequently, of the first or seventh and from the aponeurosis of the abdominal external oblique muscle.
From this extensive origin the fibers converge toward their insertion; those arising from the clavicle pass obliquely downward and outwards (laterally), and are usually separated from the rest by a slight interval; those from the lower part of the sternum, and the cartilages of the lower true ribs, run upward and laterally, while the middle fibers pass horizontally.
They all end in a flat tendon, about 5 cm in breadth, which is inserted into the lateral lip of the bicipital groove of the humerus.
Electromyography suggests that it consists of at least six groups of muscle fibres that can be independently coordinated by the central nervous system.The pectoralis major has four actions which are primarily responsible for movement of the shoulder joint.
The first action is flexion of the humerus, as in throwing a ball side-arm, and in lifting.
Secondly, it adducts the humerus, as when flapping the arms.
Thirdly, it rotates the humerus medially, as occurs when arm-wrestling.
Finally it aids in deep inspiration, as in taking a deep breath.The pectoralis major is also responsible for keeping the arm attached to the trunk of the body.
It has two different parts which are responsible for different actions.
The clavicular part is close to the deltoid muscle and contributes to flexion, horizontal adduction, and inward rotation of the humerus.
When at an approximately 110 degree angle, it contributes to abduction of the humerus.
The sternocostal part is antagonistic to the clavicular part contributing to downward and forward movement of the arm and inward rotation when accompanied by adduction.
The sternal fibers can also contribute to extension, but not beyond anatomical position.
Exercises for the Pectoralis Major
Multi-joint press exercises are better for building muscle mass, while fly and crossovers are more suited for shaping and increasing striations.
This muscle is often said to consist of four portions (upper, lower, inner and outer) but the pectoralis actually contracts evenly across all heads during most exercises and as such no portion can be 'targeted'.
Exercises for the Pectoralis Major
A variety of resistance exercises can be used to train the pectoralis major, including bench pressing (using dumbbells, barbells or machines at various angles such as decline, incline and flat where the hips are above, below and level with the head respectively), push ups, flyes (using dumbbells or machines at either flat or inclined angles), cable crossovers or dips.
Cable Flyes on an Incline Bench
Dumbbell Flyes on an Incline Bench
Multi-joint press exercises are better for building muscle mass, while fly and crossovers are more suited for shaping and increasing striations.
This muscle is often said to consist of four portions (upper, lower, inner and outer) but the pectoralis actually contracts evenly across all heads during most exercises and as such no portion can be 'targeted'.The pectoralis can also be trained through breaststroke and front crawl.
The anaerobic work capacity of the pectoralis is a major determinant of swimming speed, whereas swimming endurance is more influenced by the aerobic capacity of the deltoid muscle (apart from overall cardiopulmonary aerobic capacity).
Sexual Appeal
The pectoral muscles are commonly alleged via anecdotal evidence to be a major source of sexual appeal in male humans, demonstrating strength.
Sexual Appeal
The pectoral muscles are commonly alleged via anecdotal evidence to be a major source of sexual appeal in male humans, demonstrating strength.
Some male humans claim their development to be an asset in attracting a sexual partner.
Abdominal Muscles
The abdomen constitutes the part of the body between the thorax (chest) and pelvis.
The region enclosed by the abdomen is termed the abdominal cavity.
Anatomically, the abdomen stretches from the thorax at the thoracic diaphragm to the pelvis at the pelvic brim. The pelvic brim stretches from the lumbosacral angle (the intervertebral disk between L5 and S1) to the pubic symphysis and is the edge of the pelvic inlet.
The space above this inlet and under the thoracic diaphragm is termed the abdominal cavity.
The boundary of the abdominal cavity is the abdominal wall in the front and the peritoneal surface at the rear.
The transversus abdominis muscle is flat and triangular, with its fibers running horizontally. It lies between the inner oblique and the underlying transversalis fascia. It originates from Poupart's ligament, the inner lip of the ilium, the lumbar fascia and the inner surface of the cartilages of the six lower ribs. It inserts into the linea alba behind the rectus abdominis.
The rectus abdominis muscles are long and flat. The muscle is crossed by three tendinous intersections called the linae transversae. The rectus abdominis is enclosed in a thick sheath formed, as described above, by fibers from each of the three muscles of the lateral abdominal wall. They originate at the pubis bone, run up the abdomen on either side of the linea alba, and insert into the cartilages of the fifth, sixth, and seventh ribs.
The pyramidalis muscle is small and triangular. It is located in the lower abdomen in front of the rectus abdominis. It originates at the pubic bone and is inserted into the linea alba half way up to the umbilicus.
Functions
The abdominal muscles have different important functions. They provide movement and support to the trunk and assist in the breathing process. Moreover, these muscles serve as protection for the inner organs. Furthermore, together with the back muscles they provide postural support and are important in defining the form.
The transverse abdominus muscle is the deepest muscle, therefore, it cannot be touched from the outside. It can greatly affect the body posture. The internal obliques are also deep and also affect body posture. Both of them are involved in rotation and lateral flexion of the spine and are used to bend and support the spine from the front. The external obliques are more superficial and they are also involved in rotation and lateral flexion of the spine. Also they stabilize the spine when upright. The rectus abdominus muscle is not the most superficial abdominal muscle. The tendonous sheath extending from the external obliques cover the rectus abdominus. The Rectus abdominus is the muscle that very fit people develop into the 6-pack ab look. Although, it should really be an 8 pack as there are 4 vertical sections on each side. The 2 bottom sections are just above the pubic bone and usually not visible, hence, the 6 pack abs. The rectus abdominals' function is to bend one's back forward (flexion). The main work of the abdominal muscles is to bend the spine forward when contracting coencentrically.
Abdominal Exercises
Being a key element to support the spine and contribute to a good posture, it is important to properly exercise the abdominal muscles together with the back muscles as when weak or overly tight they can suffer painful spasms as well as injuries.
Also, when strengthened, the abdominal muscles provide flexibility as well.
Abdominal Muscles
The abdomen constitutes the part of the body between the thorax (chest) and pelvis.The region enclosed by the abdomen is termed the abdominal cavity.
Anatomically, the abdomen stretches from the thorax at the thoracic diaphragm to the pelvis at the pelvic brim. The pelvic brim stretches from the lumbosacral angle (the intervertebral disk between L5 and S1) to the pubic symphysis and is the edge of the pelvic inlet.
The space above this inlet and under the thoracic diaphragm is termed the abdominal cavity.
The boundary of the abdominal cavity is the abdominal wall in the front and the peritoneal surface at the rear.
The transversus abdominis muscle is flat and triangular, with its fibers running horizontally. It lies between the inner oblique and the underlying transversalis fascia. It originates from Poupart's ligament, the inner lip of the ilium, the lumbar fascia and the inner surface of the cartilages of the six lower ribs. It inserts into the linea alba behind the rectus abdominis.
The rectus abdominis muscles are long and flat. The muscle is crossed by three tendinous intersections called the linae transversae. The rectus abdominis is enclosed in a thick sheath formed, as described above, by fibers from each of the three muscles of the lateral abdominal wall. They originate at the pubis bone, run up the abdomen on either side of the linea alba, and insert into the cartilages of the fifth, sixth, and seventh ribs.
The pyramidalis muscle is small and triangular. It is located in the lower abdomen in front of the rectus abdominis. It originates at the pubic bone and is inserted into the linea alba half way up to the umbilicus.
Functions
The abdominal muscles have different important functions. They provide movement and support to the trunk and assist in the breathing process. Moreover, these muscles serve as protection for the inner organs. Furthermore, together with the back muscles they provide postural support and are important in defining the form.
The transverse abdominus muscle is the deepest muscle, therefore, it cannot be touched from the outside. It can greatly affect the body posture. The internal obliques are also deep and also affect body posture. Both of them are involved in rotation and lateral flexion of the spine and are used to bend and support the spine from the front. The external obliques are more superficial and they are also involved in rotation and lateral flexion of the spine. Also they stabilize the spine when upright. The rectus abdominus muscle is not the most superficial abdominal muscle. The tendonous sheath extending from the external obliques cover the rectus abdominus. The Rectus abdominus is the muscle that very fit people develop into the 6-pack ab look. Although, it should really be an 8 pack as there are 4 vertical sections on each side. The 2 bottom sections are just above the pubic bone and usually not visible, hence, the 6 pack abs. The rectus abdominals' function is to bend one's back forward (flexion). The main work of the abdominal muscles is to bend the spine forward when contracting coencentrically.
Abdominal Exercises
When properly exercised, these muscles contribute to improve posture and balance, reduce the likelihood of back pain episodes, reduce the severity of back pain, protect against injury by responding efficiently to stresses, help avoid some back surgeries, and help healing from a back problem or after spine surgery.
Hanging straight leg raise
Crunch with feet anchored - (abdominal crunch machine)
Crunch with feet free
Straight-leg sit-up
Bent-leg sit-up
Latissimus Dorsi
The latissimus dorsi (plural: latissimi dorsi), meaning 'broadest muscle of the back' (Latin latus meaning 'broad', latissimus meaning 'broadest' and dorsum meaning the back), is the larger, flat, dorso-lateral muscle on the trunk, posterior to the arm, and partly covered by the trapezius on its median dorsal region.
The latissimus dorsi is responsible for extension, adduction, transverse extension also known as horizontal abduction, flexion from an extended position, and (medial) internal rotation of the shoulder joint. It also has a synergistic role in extension and lateral flexion of the lumbar spine.
Due to bypassing the scapulothoracic joint and attaching directly to the spine, the actions the lat has on moving the arm can also influence the movement of the scapula, such as their downward rotation during a pull up.
The power/size/strength of this muscle can be trained with a variety of different exercises.
Some of these include:
Some of these include:
Vertical pulling movements such as pull-downs and pull-ups (including chin-ups)
Horizontal pulling movements using the bent-over rowing stack machine
Pull-overs
Dead-lift is NOT recommended
Pain
Most latissimus dorsi exercises concurrently recruit the teres major, posterior fibers of the deltoid, long head of the triceps brachii, among numerous other stabilizing muscles.
Compound exercises for the 'lats' typically involve elbow flexion and tend to recruit the biceps brachii, brachialis, and brachioradialis for this function.
Depending on the line of pull, the trapezius muscles can be recruited as well; horizontal pulling motions such as rows recruit both latissimus dorsi and trapezius heavily.
Tight latissimus dorsi has been shown to be one cause of chronic shoulder pain and chronic back pain. Because the latissimus dorsi connects the spine to the humerus, tightness in this muscle can manifest as either sub-optimal glenohumeral joint (shoulder) function which leads to chronic pain or tendinitis in the tendinous fasciae connecting the latissimus dorsi to the thoracic and lumbar spine.
The muscle may be loosened by stretching exercises and gentle pull-ups without resistance.
Arm Bicep
In human anatomy, the biceps brachii, or simply biceps in common parlance, is, as the name implies, a two-headed muscle.
The biceps lie on the upper arm between the shoulder and the elbow.
Both heads arise on the scapula and join to form a single muscle belly which is attached to the upper forearm. While the biceps crosses both the shoulder and elbow joints, its main function is at the latter where it flexes the elbow and supinates the forearm.
Both these movements are used when opening a bottle with a corkscrew: first biceps unscrews the cork (supination), then it pulls the cork out (flexion).
The term biceps brachii is a Latin phrase meaning "two-headed [muscle] of the arm", in reference to the fact that the muscle consists of two bundles of muscle, each with its own origin, sharing a common insertion point near the elbow joint.
The proper plural form of the Latin adjective biceps is bicipites, a form not in general English use. Instead, biceps is used in both singular and plural (i.e., when referring to both arms).
Origin and Insertion
Proximally (towards the body), the short head of the biceps originates from the coracoid process at the top of the scapula.
The long head originates from the supraglenoid tubercle just above the shoulder joint from where its tendon passes down along the intertubercular groove of the humerus into the joint capsule of the shoulder joint.
When the humerus is in motion, the tendon of the long head is held firmly in place in the intertubercular groove by the greater and lesser tubercles and the overlying transverse humeral ligament.
During the motion from external to internal rotation, the tendon is forced medially against the lesser tubercle and superiorly against the transverse ligament.
Both heads join on the middle of the humerus, usually near the insertion of the deltoid, to form a common muscle belly.
Distally (towards the fingers), biceps ends in two tendons: the stronger attaches to (inserts into) the radial tuberosity on the radius, while the other, the bicipital aponeurosis, radiates into the ulnar part of the antebrachial fascia.
Two additional muscles lie underneath the biceps brachii.
These are the coracobrachialis muscle, which like the biceps attaches to the coracoid process of the scapula, and the brachialis muscle which connects to the ulna and along the mid-shaft of the humerus.
Besides those, the brachioradialis muscle is adjacent to the biceps and also inserts on the radius bone, though more distally.
Functions
Flexed arm in the pronated position (left); with the biceps partially contracted and in a supinated position with the biceps more fully contracted, approaching minimum length (right.)
The biceps is tri-articulate, meaning that it works across three joints.
The most important of these functions is to supinate the forearm and flex the elbow.
These joints and the associated actions are listed as follows in order of importance:
Proximal radioulnar joint (upper forearm) – Contrary to popular belief, the biceps brachii is not the most powerful flexor of the forearm, a role which actually belongs to the deeper brachialis muscle.
The biceps brachii functions primarily as a powerful supinator of the forearm (turns the palm upwards).
This action, which is aided by the supinator muscle, requires the elbow to be at least partially flexed. If the elbow, or humeroulnar joint, is fully extended, supination is then primarily carried out by the supinator muscle.
Humeroulnar joint (elbow) – The biceps brachii also functions as an important flexor of the forearm, particularly when the forearm is supinated. Functionally, this action is performed when lifting an object, such as a bag of groceries or when performing a biceps curl.[pronation]] (the palm faces the ground), the brachialis, brachioradialis, and supinator function to flex the forearm, with minimal contribution from the biceps brachii.
Glenohumeral joint (shoulder) – Several weaker functions occur at the glenohumeral, or shoulder, joint.
The biceps brachii weakly assists in forward flexion of the shoulder joint (bringing the arm forward and upwards). It may also contribute to abduction (bringing the arm out to the side) when the arm is externally (or laterally) rotated.
The short head of the biceps brachii also assists with horizontal adduction (bringing the arm across the body) when the arm is internally (or medially) rotated.
Finally, the long head of the biceps brachii, due to its attachment to the scapula (or shoulder blade), assists with stabilization of the shoulder joint when a heavy weight is carried in the arm.
Bicep Exercises
Although the exercises differ, a common factor of each is a 'curling' motion, where a weight is moved through an arc, primarily using the strength of the biceps.
The fullest range of motion is when the elbows begin in full extension, in a supine grip.
The biceps contract to lift the weight upward through an arc, to a point where further movement is not possible.
Some think it important that the elbow remain next to the body during this motion to keep stress on the biceps. Others will either bring the elbows forward (to fully shorten the biceps) or bring the elbows back (a "drag curl", to avoid over-active insufficiency and keep parallel forearms) to vary the tensions placed on the biceps and other elbow flexors
The second part of the motion has the elbow joint extending, this is called the 'eccentric' portion.
The weight is lowered back to the start position.
This contraction and extension together constitute a single repetition.
As with most weight training exercises, results from biceps exercises can be maximized with a proper understanding of flexion.
Recommended exercises include:
concentration curl where the elbow is braced against the inside of the knee
preacher curl where the elbows rest upon a sloped bench
dumbbell curl
Triceps Brachii
The triceps brachii muscle (Latin for "three-headed arm muscle") is the large muscle on the back of the upper limb of many vertebrates. It is the muscle principally responsible for extension of the elbow joint (straightening of the arm).
It is sometimes called a three-headed muscle because there are three bundles of muscles, each of different origins, joining together at the elbow. Though a similarly named muscle, the triceps surae, is found on the lower leg, the triceps brachii is commonly called the triceps.
The long head arises from the infraglenoid tubercle of the scapula. It extends distally anterior to the teres minor and posterior to the teres major.
The medial head arises distally from the groove of the radial nerve; from the dorsal (back) surface of the humerus; from the medial intermuscular septum; and its distal part also arises from the lateral intermuscular septum. The medial head is mostly covered by the lateral and long heads, and is only visible distally on the humerus.
The lateral head arises from the dorsal surface of the humerus, lateral and proximal to the groove of the radial nerve, from the greater tubercle down to the region of the lateral intermuscular septum.
Each of the three fascicles has its own motorneuron subnucleus in the motor column in the spinal cord. The medial head is formed predominantly by small type I fibers and motor units, the lateral head of large type IIb fibers and motor units and the long head of a mixture of fiber types and motor units.
The fibers converge to a single tendon to insert onto the olecranon process of the ulna (though some research indicates that there may be more than one tendon) and to the posterior wall of the capsule of the elbow joint where bursae (cushion sacks) are often found. Parts of the common tendon radiates into the fascia of the forearm and can almost cover the anconeus.
Actions
The triceps is an extensor muscle of the elbow joint and an antagonist of the biceps and brachialis muscles. It can also fixate the elbow joint when the forearm and hand are used for fine movements, e.g., when writing. It has been suggested that the long head fascicle is employed when sustained force generation is demanded, or when there is a need for a synergistic control of the shoulder and elbow or both. The lateral head is used for movements requiring occasional high-intensity force, while the medial fascicle enables more precise, low-force movements.
With its origin on the scapula, the long head also acts on the shoulder joint and is also involved in retroversion and adduction of the arm.
Triceps Exercises
The triceps can be worked through either isolation or compound elbow extension movements and can contract statically to keep the arm straightened against resistance.
Isolation movements include cable push-downs, lying triceps extensions and arm extensions behind the back. Examples of compound elbow extension include pressing movements like the push up, bench press, close grip bench press (flat, incline or decline), military press and dips.
A closer grip targets the triceps more than wider grip movements.
Static contraction movements include pullovers, straight-arm pulldowns and bent-over lateral raises, which are also used to build the deltoids and latissimus dorsi.
It is important to maintain a balance between the biceps and triceps for postural and effective movement purposes.
Shoulder Muscle (Deltoid)
There are a number of small muacles which operate the shoulder joint, but the most significant shoulder muscle is the deltoid muscle.
It is called so because it is in the shape of the Greek letter Delta (triangle).
The deltoid muscle is the muscle forming the rounded contour of the shoulder.
Anatomically, it appears to be made up of three distinct sets of fibers though electromyography suggests that it consists of at least seven groups that can be independently coordinated by the central nervous system.
Deltoid is also further shortened in slang as "delt". The plural forms of all three incarnations are deltoidei, deltoids and delts.
The deltoid originates in three distinct sets of fibers, often referred to as "heads":
The anterior or clavicular fibers arises from most of the anterior border and upper surface of the lateral third of the clavicle.
The anterior origin lies adjacent to the lateral fibers of the pectoralis major muscle as do the end tendons of both muscles.
These muscle fibers are closely related and only a small chiasmatic space, through which the cephalic vein passes, prevents the two muscles from forming a continuous muscle mass.
The anterior deltoid are commonly called front delts for short.
Lateral or acromial fibers arise from the superior surface of the acromion process.
They are commonly called lateral deltoid
This muscle is also called middle delts, outer delts, or side delts for short.
Posterior or spinal fibers arise from the lower lip of the posterior border of the spine of the scapula.
They are commonly called posterior deltoid or rear deltoid (rear delts for short ).
From this extensive origin the fibers converge toward their insertion on the deltoid tuberosity on the middle of the lateral aspect of the shaft of the humerus; the middle fibers passing vertically, the anterior obliquely backward and laterally, and the posterior obliquely forward and laterally.
Though traditionally described as a single insertion, the deltoid insertion is divided into two or three discernible areas corresponding to the muscle's three areas of origin.
The insertion is an arch-like structure with strong anterior and posterior fascial connections flanking an intervening tissue bridge.
It additionally give off extensions to the deep brachial fascia. Furthermore, the deltoid fascia contributes to the brachial fascia and is connected to the medial and lateral intermuscular septa.
Action of the Deltoid Muscle
When all its fibers contract simultaneously, the deltoid is the prime mover of arm abduction along the frontal plane.
The arm must be medially rotated for the deltoid to have maximum effect.
This makes the deltoid an antagonist muscle of the pectoralis major and latissimus dorsi during arm adduction.
The anterior fibers are involved in shoulder abduction when the shoulder is externally rotated.
The anterior deltoid is weak in strict transverse flexion but assists the pectoralis major during shoulder transverse flexion / shoulder flexion (elbow slightly inferior to shoulders).
The anterior deltoid also works in tandem with the subscapularis, pecs and lats to internally (medially) rotate the humerus.
The posterior fibers are strongly involved in transverse extension particularly as the latissimus dorsi is very weak in strict transverse extension. Other transverse extensors, the infraspinatus and teres minor, also work in tandem with the posterior deltoid as external (lateral) rotators, antagonists to strong internal rotators like the pecs and lats. The posterior deltoid is also the primary shoulder hyperextensor, moreso than the long head of the triceps which also assists in this function.
The lateral fibers perform basic shoulder abduction when the shoulder is internally rotated, and perform shoulder transverse abduction when the shoulder is externally rotated. They are not utilized significantly during strict transverse extension (shoulder internally rotated) such as in rowing movements, which use the posterior fibers.
An important function of the deltoid in humans is stopping: preventing the dislocation of the humeral head when a person carries heavy loads.
The function of abduction also means that it would help keep carried objects a safer distance away from the thighs to avoid hitting them, such as during a farmer's walk. It also ensures a precise and rapid movement of the glenohumeral joint needed for hand and arm manipulation.
The lateral fibers are in the most efficient position to perform this role, though like basic abduction movements (such as lateral raise) it is assisted by simultaneous co-contraction of anterior/posterior fibers.
In both the carrying of heavy loads and in lateral raises, the deltoid often contracts in tandem with scapular elevators such as the levator scapulae, upper trapezius or serratus anterior.
By pulling the clavicle and scapulae up, it reduces compression and possibly impingement on the inferior borders so it doesn't press as much against the uppermost ribs.
The deltoid is responsible for elevating the arm in the scapular plane and its contraction in doing this also elevates the humeral head.
To stop this compressing against the undersurface of the acromion the humeral head and injuring the supraspinatus tendon, there is a simultaneous contraction of some of the muscles of the rotator cuff: the infraspinatus and subscapularis primarily perform this role.
In spite of this there may be still a 1–3 mm upward movement of the head of the humerus during the first 30° to 60° of arm elevation.
Deltoid Exercises
The lateral raise works the deltoid muscle of the shoulder.
The movement starts with the arms straight, and the hands holding weights at the sides or in front of the body. Arms are kept straight or slightly bent, and raised through an arc of movement in the coronal plane that terminates when the hands are at approximately shoulder height.
Weights are lowered to the starting position, completing one "rep".
When using a cable machine the individual stands with the coronal plane in line with the pulley, which is at or near the ground.
The exercise can be completed one shoulder at a time (with the other hand used to stabilize the body against the weight moved), or with both hands simultaneously if two parallel pulleys are available.
This movement, when the shoulder is kept in neutral rotation, primarily targets the middle head of the deltoid. The anterior (front) and posterior (back) heads of the deltoid will also co-contract to aid in the abduction function.
If the shoulder is laterally (externally, outwardly) rotated, the anterior deltoid becomes the prime mover of the glenohumeral joint, the posterior deltoid de-activates, and the middle head assists.
A similar exercise is upright rowing.
The upright row is a weight training exercise performed by holding a grips with the overhand grip and lifting it straight up to the collarbone.
This is a compound exercise that involves the trapezius, the deltoids and the biceps.
The narrower the grip the more the trapezius muscles are exercised, as opposed to the deltoids.
Barbells, Dumbbells, an EZ Curl bar, or a cable machine can be used.
The Trapezius Muscle
The trapezius is a large superficial muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae and laterally to the spine of the scapula (shoulder blade). Its functions are to move the scapulae and support the arm.
The trapezius has three functional regions: the superior region (descending part), which supports the weight of the arm; the intermediate region (transverse part), which retracts the scapulae; and the inferior region (ascending part), which medially rotates and depresses the scapulae.
The superior or upper fibers of the trapezius arise from the external occipital protuberance, the medial third of the superior nuchal line of the occipital bone (both in the back of the head), and the ligamentum nuchae.
At the middle, the muscle is connected to the spinous processes by a broad semi-elliptical aponeurosis, which reaches from the sixth cervical to the third thoracic vertebræ and forms, with that of the opposite muscle, a tendinous ellipse. The rest of the muscle arises by numerous short tendinous fibers.
Actions and Exercises
Arm Bicep
In human anatomy, the biceps brachii, or simply biceps in common parlance, is, as the name implies, a two-headed muscle.The biceps lie on the upper arm between the shoulder and the elbow.
Both heads arise on the scapula and join to form a single muscle belly which is attached to the upper forearm. While the biceps crosses both the shoulder and elbow joints, its main function is at the latter where it flexes the elbow and supinates the forearm.
Both these movements are used when opening a bottle with a corkscrew: first biceps unscrews the cork (supination), then it pulls the cork out (flexion).
The term biceps brachii is a Latin phrase meaning "two-headed [muscle] of the arm", in reference to the fact that the muscle consists of two bundles of muscle, each with its own origin, sharing a common insertion point near the elbow joint.
The proper plural form of the Latin adjective biceps is bicipites, a form not in general English use. Instead, biceps is used in both singular and plural (i.e., when referring to both arms).
Origin and Insertion
Proximally (towards the body), the short head of the biceps originates from the coracoid process at the top of the scapula.
The long head originates from the supraglenoid tubercle just above the shoulder joint from where its tendon passes down along the intertubercular groove of the humerus into the joint capsule of the shoulder joint.
When the humerus is in motion, the tendon of the long head is held firmly in place in the intertubercular groove by the greater and lesser tubercles and the overlying transverse humeral ligament.
During the motion from external to internal rotation, the tendon is forced medially against the lesser tubercle and superiorly against the transverse ligament.
Both heads join on the middle of the humerus, usually near the insertion of the deltoid, to form a common muscle belly.
Distally (towards the fingers), biceps ends in two tendons: the stronger attaches to (inserts into) the radial tuberosity on the radius, while the other, the bicipital aponeurosis, radiates into the ulnar part of the antebrachial fascia.
Two additional muscles lie underneath the biceps brachii.
These are the coracobrachialis muscle, which like the biceps attaches to the coracoid process of the scapula, and the brachialis muscle which connects to the ulna and along the mid-shaft of the humerus.
Besides those, the brachioradialis muscle is adjacent to the biceps and also inserts on the radius bone, though more distally.
Functions
The biceps is tri-articulate, meaning that it works across three joints.
The most important of these functions is to supinate the forearm and flex the elbow.
These joints and the associated actions are listed as follows in order of importance:
Proximal radioulnar joint (upper forearm) – Contrary to popular belief, the biceps brachii is not the most powerful flexor of the forearm, a role which actually belongs to the deeper brachialis muscle.
The biceps brachii functions primarily as a powerful supinator of the forearm (turns the palm upwards).
This action, which is aided by the supinator muscle, requires the elbow to be at least partially flexed. If the elbow, or humeroulnar joint, is fully extended, supination is then primarily carried out by the supinator muscle.
Humeroulnar joint (elbow) – The biceps brachii also functions as an important flexor of the forearm, particularly when the forearm is supinated. Functionally, this action is performed when lifting an object, such as a bag of groceries or when performing a biceps curl.[pronation]] (the palm faces the ground), the brachialis, brachioradialis, and supinator function to flex the forearm, with minimal contribution from the biceps brachii.
Glenohumeral joint (shoulder) – Several weaker functions occur at the glenohumeral, or shoulder, joint.
The biceps brachii weakly assists in forward flexion of the shoulder joint (bringing the arm forward and upwards). It may also contribute to abduction (bringing the arm out to the side) when the arm is externally (or laterally) rotated.
The short head of the biceps brachii also assists with horizontal adduction (bringing the arm across the body) when the arm is internally (or medially) rotated.
Finally, the long head of the biceps brachii, due to its attachment to the scapula (or shoulder blade), assists with stabilization of the shoulder joint when a heavy weight is carried in the arm.
Bicep Exercises
The fullest range of motion is when the elbows begin in full extension, in a supine grip.
The biceps contract to lift the weight upward through an arc, to a point where further movement is not possible.
Some think it important that the elbow remain next to the body during this motion to keep stress on the biceps. Others will either bring the elbows forward (to fully shorten the biceps) or bring the elbows back (a "drag curl", to avoid over-active insufficiency and keep parallel forearms) to vary the tensions placed on the biceps and other elbow flexors
The second part of the motion has the elbow joint extending, this is called the 'eccentric' portion.
The weight is lowered back to the start position.
This contraction and extension together constitute a single repetition.
Recommended exercises include:
concentration curl where the elbow is braced against the inside of the knee
preacher curl where the elbows rest upon a sloped bench
dumbbell curl
Triceps Brachii
It is sometimes called a three-headed muscle because there are three bundles of muscles, each of different origins, joining together at the elbow. Though a similarly named muscle, the triceps surae, is found on the lower leg, the triceps brachii is commonly called the triceps.
The long head arises from the infraglenoid tubercle of the scapula. It extends distally anterior to the teres minor and posterior to the teres major.
The medial head arises distally from the groove of the radial nerve; from the dorsal (back) surface of the humerus; from the medial intermuscular septum; and its distal part also arises from the lateral intermuscular septum. The medial head is mostly covered by the lateral and long heads, and is only visible distally on the humerus.
Each of the three fascicles has its own motorneuron subnucleus in the motor column in the spinal cord. The medial head is formed predominantly by small type I fibers and motor units, the lateral head of large type IIb fibers and motor units and the long head of a mixture of fiber types and motor units.
The fibers converge to a single tendon to insert onto the olecranon process of the ulna (though some research indicates that there may be more than one tendon) and to the posterior wall of the capsule of the elbow joint where bursae (cushion sacks) are often found. Parts of the common tendon radiates into the fascia of the forearm and can almost cover the anconeus.
Actions
With its origin on the scapula, the long head also acts on the shoulder joint and is also involved in retroversion and adduction of the arm.
Triceps Exercises
Isolation movements include cable push-downs, lying triceps extensions and arm extensions behind the back. Examples of compound elbow extension include pressing movements like the push up, bench press, close grip bench press (flat, incline or decline), military press and dips.
A closer grip targets the triceps more than wider grip movements.
Static contraction movements include pullovers, straight-arm pulldowns and bent-over lateral raises, which are also used to build the deltoids and latissimus dorsi.
It is important to maintain a balance between the biceps and triceps for postural and effective movement purposes.
Shoulder Muscle (Deltoid)
There are a number of small muacles which operate the shoulder joint, but the most significant shoulder muscle is the deltoid muscle.It is called so because it is in the shape of the Greek letter Delta (triangle).
The deltoid muscle is the muscle forming the rounded contour of the shoulder.
Anatomically, it appears to be made up of three distinct sets of fibers though electromyography suggests that it consists of at least seven groups that can be independently coordinated by the central nervous system.
Deltoid is also further shortened in slang as "delt". The plural forms of all three incarnations are deltoidei, deltoids and delts.
The deltoid originates in three distinct sets of fibers, often referred to as "heads":
The anterior or clavicular fibers arises from most of the anterior border and upper surface of the lateral third of the clavicle.
The anterior origin lies adjacent to the lateral fibers of the pectoralis major muscle as do the end tendons of both muscles.
These muscle fibers are closely related and only a small chiasmatic space, through which the cephalic vein passes, prevents the two muscles from forming a continuous muscle mass.
The anterior deltoid are commonly called front delts for short.
Lateral or acromial fibers arise from the superior surface of the acromion process.
They are commonly called lateral deltoid
This muscle is also called middle delts, outer delts, or side delts for short.
Posterior or spinal fibers arise from the lower lip of the posterior border of the spine of the scapula.
They are commonly called posterior deltoid or rear deltoid (rear delts for short ).
From this extensive origin the fibers converge toward their insertion on the deltoid tuberosity on the middle of the lateral aspect of the shaft of the humerus; the middle fibers passing vertically, the anterior obliquely backward and laterally, and the posterior obliquely forward and laterally.
Though traditionally described as a single insertion, the deltoid insertion is divided into two or three discernible areas corresponding to the muscle's three areas of origin.
The insertion is an arch-like structure with strong anterior and posterior fascial connections flanking an intervening tissue bridge.
It additionally give off extensions to the deep brachial fascia. Furthermore, the deltoid fascia contributes to the brachial fascia and is connected to the medial and lateral intermuscular septa.
Action of the Deltoid Muscle
When all its fibers contract simultaneously, the deltoid is the prime mover of arm abduction along the frontal plane.
The arm must be medially rotated for the deltoid to have maximum effect.
This makes the deltoid an antagonist muscle of the pectoralis major and latissimus dorsi during arm adduction.
The anterior fibers are involved in shoulder abduction when the shoulder is externally rotated.
The anterior deltoid is weak in strict transverse flexion but assists the pectoralis major during shoulder transverse flexion / shoulder flexion (elbow slightly inferior to shoulders).
The anterior deltoid also works in tandem with the subscapularis, pecs and lats to internally (medially) rotate the humerus.
The posterior fibers are strongly involved in transverse extension particularly as the latissimus dorsi is very weak in strict transverse extension. Other transverse extensors, the infraspinatus and teres minor, also work in tandem with the posterior deltoid as external (lateral) rotators, antagonists to strong internal rotators like the pecs and lats. The posterior deltoid is also the primary shoulder hyperextensor, moreso than the long head of the triceps which also assists in this function.
An important function of the deltoid in humans is stopping: preventing the dislocation of the humeral head when a person carries heavy loads.
The function of abduction also means that it would help keep carried objects a safer distance away from the thighs to avoid hitting them, such as during a farmer's walk. It also ensures a precise and rapid movement of the glenohumeral joint needed for hand and arm manipulation.
The lateral fibers are in the most efficient position to perform this role, though like basic abduction movements (such as lateral raise) it is assisted by simultaneous co-contraction of anterior/posterior fibers.
In both the carrying of heavy loads and in lateral raises, the deltoid often contracts in tandem with scapular elevators such as the levator scapulae, upper trapezius or serratus anterior.
The deltoid is responsible for elevating the arm in the scapular plane and its contraction in doing this also elevates the humeral head.
To stop this compressing against the undersurface of the acromion the humeral head and injuring the supraspinatus tendon, there is a simultaneous contraction of some of the muscles of the rotator cuff: the infraspinatus and subscapularis primarily perform this role.
In spite of this there may be still a 1–3 mm upward movement of the head of the humerus during the first 30° to 60° of arm elevation.
Deltoid Exercises
The lateral raise works the deltoid muscle of the shoulder.
The movement starts with the arms straight, and the hands holding weights at the sides or in front of the body. Arms are kept straight or slightly bent, and raised through an arc of movement in the coronal plane that terminates when the hands are at approximately shoulder height.Weights are lowered to the starting position, completing one "rep".
The exercise can be completed one shoulder at a time (with the other hand used to stabilize the body against the weight moved), or with both hands simultaneously if two parallel pulleys are available.
This movement, when the shoulder is kept in neutral rotation, primarily targets the middle head of the deltoid. The anterior (front) and posterior (back) heads of the deltoid will also co-contract to aid in the abduction function.
If the shoulder is laterally (externally, outwardly) rotated, the anterior deltoid becomes the prime mover of the glenohumeral joint, the posterior deltoid de-activates, and the middle head assists.
A similar exercise is upright rowing.
The upright row is a weight training exercise performed by holding a grips with the overhand grip and lifting it straight up to the collarbone.This is a compound exercise that involves the trapezius, the deltoids and the biceps.
Upright Rowing with a Cable Machine
The narrower the grip the more the trapezius muscles are exercised, as opposed to the deltoids.
Barbells, Dumbbells, an EZ Curl bar, or a cable machine can be used.
Upright Rowing with Smith Machine
(reccomended)
The Trapezius Muscle
The trapezius is a large superficial muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae and laterally to the spine of the scapula (shoulder blade). Its functions are to move the scapulae and support the arm.The trapezius has three functional regions: the superior region (descending part), which supports the weight of the arm; the intermediate region (transverse part), which retracts the scapulae; and the inferior region (ascending part), which medially rotates and depresses the scapulae.
The superior or upper fibers of the trapezius arise from the external occipital protuberance, the medial third of the superior nuchal line of the occipital bone (both in the back of the head), and the ligamentum nuchae.
From this origin they proceed downward and laterally to be inserted into the posterior border of the lateral third of the clavicle.
The middle fibers of the trapezius arise from the spinous process of the seventh cervical (both in the back of the neck), and the spinous processes of the first, second and third thoracic vertebrae.
They are inserted into the medial margin of the acromion, and into the superior lip of the posterior border of the spine of the scapula.
The inferior or lower fibers of the trapezius arise from the spinous processes of the remaining thoracic vertebrae (T4-T12).
From this origin they proceed upward and laterally to converge near the scapula and end in an aponeurosis, which glides over the smooth triangular surface on the medial end of the spine, to be inserted into a tubercle at the apex of this smooth triangular surface.
At its occipital origin, the trapezius is connected to the bone by a thin fibrous lamina, firmly adherent to the skin. The superficial and deep epimysia are continuous with an investing deep fascia that encircles the neck and also contains both sternocleidomastoid muscles.
Actions and Exercises
Contraction of the trapezius muscle can have two effects: movement of the scapulae when the spinal origins are stable, and movement of the spine when the scapulae are stable.
The upper portion of the trapezius can be developed by elevating the shoulders.
Common exercises for this movement are shoulder shrugs and upright rowing (using cables or a Smith Machine - see above).
Middle fibers are developed by pulling shoulder blades together.
This adduction also uses the upper/lower fibers too.
The lower part can be developed by drawing the shoulder blades downward while keeping the arms almost straight and stiff.
It is mainly used in throwing, with the deltoid muscles.
The upper and lower trapezius fibers also work in tandem with the serratus anterior to upwardly rotate the scapulae, such as during an Shoulder press (use a shoulder press machine or a Smith Machine).
When activating together, the upper and lower fibers also assist the middle fibers (along with other muscles such as the rhomboids) with scapular retraction/adduction.
No comments:
Post a Comment