latissimus dorsi action

[WP,unvetted]. anatomy muscles Pain is usually caused by overuse , using poor technique , or not warming up before exercising. Activities that can cause latissimus dorsi pain include: You might also feel pain in your latissimus dorsi if you have poor posture or tend to slouch. In rare cases, your latissimus dorsi can tear. Normal … Variation in the insertion of the latissimus dorsi & its ... That forceful lowering action is adduction. Manual Muscle With the arms fixed above the head, it can raise the trunk upwards, together with the help of pectoralis major. Back (latissimus dorsi flap). Anatomy, Back, Latissimus Dorsi - StatPearls - NCBI … The latissimus dorsi inserts, not on the shoulder blade, but on the bone below it, the humerus. Latissimus Dorsi actions mainly are Extension, Adduction and Internal Rotation of the upper limb. Latissimus Dorsi The latissimus dorsi muscle attaches to the spinous processes of T7 inferiorly to the sacrum via the thoracolumbar fascia, and inserts laterally into the intertubercular groove of the humerus. Autologous Reconstructive Breast Surgery (includes DIEP, TRAM, DUG, VUG, TUG, PAP, SGAP, Latissimus Dorsi) Implant-based Reconstructive Breast Surgery Surgical Treatment of Lymphedema (includes vascularized lymph node transfer, lymphovenous bypass, liposuction, and excision) Lower Extremity, Trunk, and Perineal Reconstruction It's sometimes called "lat's little helper" because of its synergistic action with the latissimus dorsi. An electrophysiological and morphological study of normal ... You may have damaged or injured the latissimus dorsi muscle if you experience any of the following symptoms: Dull ache in back, arms, or hands when raising or reaching with arms. All you need is a pull-up bar or similar equipment that allows you to do chin-ups. Latissimus dorsi injury | Radiology Reference Article ... Just think about the action of a pull-up for a minute—an exercise that targets the lats. Spinous processes of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs. The Latissimus dorsi, which is located in the back, is one of the widest muscles in the body. Due to its size and power, latissimus has the potential to affect a wide range of actions in the body. Latissimus Dorsi Action. Latissimus Dorsi is not used strenuously in common daily activities but is an important muscle in many exercises such as pull-ups, chin-ups, lat pull-downs, and swimming. What action does the latissimus dorsi perform ... Refer back to our breakdown at the beginning of the article to learn exactly what action the Latissimus Dorsi is responsible for, and at what joint the action occurs. Extends, adducts, and medially rotates humerus; raises body toward arms during climbing. Because of its many actions associated with movements of swimming, it’s known as the swimmer’s muscle. It is relatively thin and covers almost all back muscles at the posterior trunk, except the trapezius.. Latissimus dorsi, like pectoralis major, is a powerful adductor of the humerus. The pectoralis major is a large muscle that comprises the chest. Instructions: Reach your hand down towards the middle back region. William J. Casey, III Intertubercular groove muscles. Therefore, after the latissimus dorsi is transferred, the teres minor muscle acts in a synergistic manner, compensating for the loss of the latissimus dorsi. It has been observed anecdotally that while performing the multijoint lat pull-down exercise, novice strength trainers often rely on the elbow flexors to complete the movement rather than fully utilizing the relevant back muscles such as the latissimus dorsi (LD) and teres major (TM). Thoracodorsal nerve ( nerve to latissimus dorsi) Action: Adduction, extension and medial rotation of the shoulder; Levator scapulae: The levator scapulae is a small strap-like muscle. Yes, the latissimus dorsi does compress the abdomen. as in pull-ups but also adduct (pull against torso) and internally rotate (roll towards sternum) these bones. Latissimus Dorsi Innervation. C. Protract the arm. latissimus dorsi process. Teres major often gets discussed along with the latissimus muscle because it’s a small muscle whose main job is to assist latissimus in some of its actions. It is relatively thin and covers almost all back muscles at the posterior trunk, except the trapezius.. The primary joint actions that occur during the lat pulldown are listed below however, it is important to note that accessory joint motions occur depending on how the individual performs the exercise. Restoration of elbow active flexion via latissimus dorsii transfer in patients with arthrogryposis. B. Adduct the arm. Description [edit | edit source]. Where in the body is the latissimus dorsi located? It completely surrounds the shoulder joint from the front, to the back. As mentioned before, the Latissimus Dorsi has multiple actions. It is large, flat and triangular in shape originating from large parts of the lumbar region and lower thorax to insert on the humerus through a narrow tendon. Origin, spinous processes of the lower five or six thoracic and the lumbar vertebrae, median ridge of sacrum, and outer lip of iliac crest; insertion, with teres major into posterior lip of bicipital groove of humerus; action, adducts arm, rotates it medially, and extends it; nerve supply, thoracodorsal. levator scapulae muscle. Latissimus Dorsi: Action. It actually inserts on the inside of that bone, on a small protuberance called the teres major tuberosity. For the upper body, the muscle group that does the most adduction of the arms is the latissimus dorsi. Your latissimus dorsi muscle is the largest muscle in your back. Strengthening these muscles helps give you a wider upper back, or V-shaped torso.Latissimus dorsi muscle strains, while uncommon, usually result from traumatic events, in combination with damage to other structures in your shoulder or shoulder blade and can often … lesser tubercle of humerus. Posterior sacrum. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Last of all, here's the deltoid muscle. Our lats have a … It is best to use the blunt probe and rip away the connective tissue in the armpit, which will let you see the latissimus dorsi more clearly. B. The latissimus dorsi is a large, flat muscle covering the width of the middle and lower back. Pull the elbow towards the midline. Thoracodorsal nerve (C6, C7, and C8) (C6, C7, C8) Draws thoracic limb caudally, flexes shoulder, draws trunk forward. The teres major is a relatively small round muscle located on the upper sides of the back that works together with the latissimus dorsi in a multitude of actions. The latissimus dorsi inserts, not on the shoulder blade, but on the bone below it, the humerus. When observing the muscle action of the origin towards the insertion, the lats are a very powerful rotator of the trunk. We have also learned that without this particular muscle, movement is more often than not unaffected. In this article, we will discuss the anatomy and function of the levator scapulae muscle. The latissimus dorsi muscles, or lats, originate on the upper back of the pelvis and on the vertebrae of the lower and lower middle back. It is also known as Broadest muscle of the back. latissimus dorsi pre-muscle mass +. The latissimus dorsi plays an important role in internal rotation power during the late cocking and acceleration phase of the throwing movement 1,2. Your latissimus dorsi, more commonly referred to as the lats, is a big, flat, triangularly shaped muscle that covers the width of your middle and lower back. Extension, horizontal abduction, external rotation. Yoga for Latissimus Dorsi Pain latissimus dorsi, widest and most powerful muscle of the back. However, think of the opposite movement. latissimus dorsi ORIGIN Spine T7, spinous processes and supraspinous ligaments of all lower thoracic, lumbar and sacral vertebrae, lumbar fascia, posterior third iliac crest, last four ribs (interdigitating with external oblique abdominis) and inferior angle of scapula The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula.It moves the scapula and supports the arm.. Elbow pull. Exercise and stretches are a vital part of treatment and can help relieve pain. Action: Depression and Upward rotation of scapula Innervation: Accessory Nerve (CN XI) Latissimus Dorsi. Latissimus dorsi muscle (Musculus latissimus dorsi) The latissimus dorsi muscle (AKA: 'the lats muscle' or 'the lats') is the widest muscle in the human body. Latissimus Dorsi is not used strenuously in common daily activities but is an important muscle in many exercises such as pull-ups, chin-ups, lat pull-downs, and swimming. Deltoid. An action common to the latissimus dorsi, the teres major, the subscapularis, and the pectoralis major muscles is _____. When you are taking anatomy and physiology you will be required to identify major muscles in the human body. You should end up with several empty "holes" or cavities near the arm where connective tissue has been cleared out. The latissimus dorsi is the most extensive muscle in the body, covering (if you include its connective tissue) the entire lower back, a large swath of the mid-back, and much of the sides of the trunk before running upward to form most of the outer wall of the armpit. They are commonly known at the lats. It begins in the neck and descends to attach to the scapula. Action: Patient extends arm behind them, examiner applies resistance at or below elbow Gravity eliminated position: Side lying on unaffected side with affected arm supported Latissimus Dorsi Origin: Inferior angle of scapula, spinous processes of T6-T12 vertebrae, ribs 8-12, thoracolumbar aponeurosis, and posterior iliac crest Action: Extends, adducts, and medially rotates humerus; raises body toward arms during climbing. The lats, aka the latissimus dorsi, are the large muscles of the back. The latissimus dorsi muscle is a thin, broad, triangular-shaped muscle located at each side of the back, under the arms. These muscles are located on either side of the back and travel from the back of the shoulder all the way down to the hips. The latissimus dorsi is a large, powerful muscle on the back of the torso. To stretch one Latissimus Dorsi at a time, reach out both arms to the opposite side. It connects the bone of the upper arm to the spine and the hip. If you lift weights, you've probably done exercises for your latissimus dorsi muscles — or lats. The latissimus dorsi muscle, whose name means “broadest muscle of the back,” is one of the widest muscles in the human body. The lat muscles are involved in pulling motions, like pulling open a door or, in exercise, doing a pull-up. During a cough or sneeze, the muscle can be felt pressing forcibly inward, as it acts to compress the thorax and abdomen. Insertion: Floor of intertubercular groove of humerus. This muscle can be easily damaged as it is in constant motion with most of the movements we make throughout the day. Latissimus Dorsi Muscle – Attachments, Action & Innervation Latissimus Dorsi is one of four muscles responsible for the thoracobrachial motion. The actions of levator scapulae are facilitated by actions of the trapezius, latissimus dorsi, rhomboids, pectoralis major and minor muscles. Muscle Origins & Insertions - … If you've injured your lats while doing a specific exercise, you might identify the problem right away. Symptoms of a pulled muscle in the back can include sharp pain, bruising or redness from blood vessel damage, swelling, muscle spasms, difficulty moving or weakness. Action: Flexion, adduction, and medial rotation of the arm at the shoulder -- Select -- Supraspinatus Trapezius Triceps brachii Infraspinatus Deltoid Pectoralis major Subscapularis Biceps brachii Teres minor Latissimus dorsi A broad, flat muscle of the lower region of the back. Teres major is a small muscle that runs along the lateral border of the scapula. It's sometimes called "lat's little helper" because of its synergistic action with the latissimus dorsi. asked Aug 27, 2019 in Health & Biomechanics by Laurie. Additionally, levator scapulae acts with the trapezius, latissimus dorsi, rhomboids, pectoralis major and pectoralis minor muscles to inferiorly rotate the glenoid cavity, stabilize the spine, and extend and laterally flex the neck. Note that the insertion of latissimus dorsi is between the insertion for pectoralis major and teres major. The latissimus dorsi is the widest muscle in the human body and is also known as the lats. Pull ups, an exercise that is all about the lats, are one of the most difficult exercises to master. Abstract. Note that the latissimus dorsi is one of the five muscles in the group we refer to as the muscles that move the arm (not including the rotator cuff muscles). Fun Fact: latissimus dorsi. Longissimus Costarum (iliocostalis) Origin. These actions of the humerus include: The action of the LATISSIMUS DORSI muscle is to... A. Retract the arm. The latissimus dorsi is a flat, triangular-shaped muscle located on the posterior trunk. The word latissimus dorsi (plural: latissimi dorsi) comes from Latin and means "broadest [muscle] of the back", from "latissimus" (Latin: broadest)' and "dorsum" (Latin: back). Its inferior origin arises from the posterior aspect … All but a small portion of it is visible from the surface of the body, which lies deep to the lower trapezius. The lats are a very hard muscle to access and make good use of. There muscle is divided into two segments, which are configured symmetrically along the backbone. It is an important muscle in rowing, swimming (especially during the downstroke) and chopping. 12. It is responsible for extension,adduction, and (medial) internal rotation of the shoulder joint. https://radiopaedia.org/articles/latissimus-dorsi-injury?lang=us Latissimus dorsi. Insertion. Latissimus Dorsi is a large, flat triangular muscle that covers a large area of the lower back and is overlapped by the trapezius. Since there is usually not as much tissue there as from an abdominal wall (tummy) donor site, this type of flap is often used with a breast implant to add volume (size) to breast reconstruction. What does the latissimus dorsi muscle do? Latissimus dorsi To allow antagonistic pairs to work efficiently, other muscles called fixators assist by supporting and stabilising the joint and the rest of the body. innervated by the thoracodorsal nerve (C6, C7, C8) Where does the latissimus dorsi arise f…. Muscle anatomy quiz for anatomy and physiology! The lat is situated inferior to the teres major and superior to the pelvis. [There are 50 muscles you MUST now ready for your Level 3 Anatomy and Physiology exam – today we will dive deep into understanding everything about the Latissimus Dorsi. Latissimus Dorsi is one of four muscles responsible for the thoracobrachial motion. The latissimus dorsi muscle is used the most during exercises that involve pulling and throwing. It is a large, flat, triangular muscle covering the lower back. Place your other hand onto the elbow of the hand that is reaching down the back. The action of the latissimus dorsi draws the upper arm … It is the largest and strongest rotator cuff muscle, and, in addition to its importance during throwing and racquet sports, it is an important stabilizer of the shoulder joint. Also known as the “lat,” it is a very thin triangular muscle that is not used strenuously in common daily activities but is an important muscle in many exercises such as pull-ups, chin-ups, lat pulldowns, and swimming. What Causes Latissimus Dorsi Pain? I have written about the lattissimus dorsi, or the lats, a number of times lately. Hold for 30 seconds. The latissimus dorsi is also one of the muscles that help you with breathing. Climbing is an activity that recruits your latissimus dorsi. Latissimus Dorsi Pain Symptoms. The primary ai … Muscles connecting the upper extremity to the vertebral column. This all means that traditional rowing motions with your arms by your sides pulling straight … Due to this muscle's broad attachment on the spinous processes, ongoing research is looking at what, if any, role the muscle plays in trunk … Note that the insertion of latissimus dorsi is between the insertion for pectoralis major and teres major. All the lumps and bumps and rough spots on bones are there for a reason, and the reason is commonly a place for muscle attachment. exercise emphasized the muscle action of the pectoralis major more than that of the latissimus dorsi, and the higher activation depended on the external force le ver arm produced. Scoliosis is a condition in which the spine curves to either side. In the case of arm abduction, it is the movement of the arms away from the body within the plane of the torso (sagittal plane). The Shoulder girdle muscles move the clavicle (collar bone) and the scapula (shoulder blade). Latissimus dorsi. … Latissimus Dorsi. Covering the majority of the back, the latissimus dorsi is part of the superficial posterior axioappendicular (extrinsic shoulder) muscle group. Muscles of the Glenohumeral Joint Latissimus dorsi muscle. As extensor muscles, the lats primarily have the job of helping to lift the arms up as they lengthen and reach. kinesiology; An action common to the latissimus dorsi, … This quiz requires labeling, so it will test your knowledge on how to identify these muscles (latissimus dorsi, trapezius, deltoid, biceps brachii, triceps brachii, brachioradialis, pectoralis major, serratus anterior, rectus … Origin – Posterior crest of the ilium (via the Thoracolumbar fascia). 52 of 95. It functions to stabilize your back while extending your shoulders.The latissimus dorsi muscle is often called the "lats" or the latissimus for short. The latissimus dorsi is also one of the muscles that help you with breathing. The Latissimus dorsi, which is located in the back, is one of the widest muscles in the body. INNERVATING NERVE. Latissimus dorsi attaches to the inferior angle of the scapula. In fact, you may not even realize that you have pulled lat muscles, as some people just feel generalized back pain. This muscle is innervated format he thoracodorsal nerve (fibers from the C6-C8 nerve roots) ACTION. Latissimus Dorsi Muscle:. Latissimus Dorsi Origin and Insertion is a sure-fire muscle that will come up in your level 3 anatomy & physiology exam. What are the 5 places where the latissi…. Extension, adduction, internal rotation: Term. Ilium; adjacent ribs several segments caudal … The latissimus dorsi muscle is a broad, flat muscle that occupies the majority of the lower posterior thorax. Latissimus Dorsi: The latissimus dorsi is an enormous, flat muscle on the back that draws to the sides, behind the arm, and is partly camouflaged by the trapezius on the back near thmidlifene. Topic. Normal … 10. Pain is usually caused by overuse, using … It can be easy to become confused! Other muscles act as agonist and antagonist pairs to provide excellent range of motion in the shoulder. Targets the deltoids, latissimus dorsi, triceps, glutes, and core. latissimus dorsi muscle. It is large, flat and triangular in shape originating from large parts of the lumbar region and lower thorax to insert on the humerus through a narrow tendon. Definition. The latissimus dorsi muscle is one of the largest muscles in the back. Wide Grip Pull Up. Latissimus Dorsi Strengtheners in Yoga. Origin: Transverse process of first four cervical vertebrae (C1 –C4 ) Insertion: The latissimus dorsi muscles — commonly just called “the lats” — are the two biggest, broadest muscles in your back and, overall, one of the largest muscle groups in the whole body. All the lumps and bumps and rough spots on bones are there for a reason, and the reason is commonly a place for muscle attachment. Teres major is a small muscle that runs along the lateral border of the scapula. Floor of intertubercular groove of humerus. ... and you should not take any action before consulting with a healthcare professional. The latissimus dorsi is a very large muscle located over a wide area of the lower half and upper sides of the back. It forms the inferior border of both the triangular space and quadrangular space. Latissimus dorsi. Definition. Katie Thompson. The latissimus dorsi muscle is used the most during exercises that involve pulling and throwing. However, during the large range of motion required in baseball pitching, it may change its function in different positions and orientations of the humerus in reference to the trunk. Latissmus dorsi is a climbing muscle. The latissimus dorsi muscle is one of the largest muscles in the back. The first muscle I am going to look at is the latissimus dorsi (lats). the lattisumus dorsi that are at … The muscles of the shoulder girdle are serratus anterior, pectoralis minor, levator scapulae, rhomboids, and trapezius. You, of course, have two lats, one on each side of your spine. It has a large, triangular shape and works when you do exercises such as swimming and pull-ups. The latissimus dorsi flap is a pedicle flap used for breast reconstruction. D. Rotate the art. The Latissimus dorsi muscle is one of the largest in the body. It also helps in extension and lateral flexion of the lumbar spine. The latissimus dorsi 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. Latissimus Dorsi is one of four muscles responsible for the thoracobrachial motion. Latissimus dorsi muscle. of the pectoralis major and latissimus dorsi during the pullover exercise. Latissimus dorsi works collaboratively with the teres major and pectoralis major to perform actions of the upper extremity. Along with the levator scapulae, trapezius and rhomboid muscles, the latissimus dorsi belongs to the superficial layer … An action common to the posterior deltoid, teres minor, and infraspinatus is _____. Spinous processes of T7-L5. The muscle's primary function is of the upper extremity but is also considered to be a respiratory accessory muscle. Infraspinatus muscle lies on the dorsal surface of the scapula, deep to trapezius, and parts of the deltoid and latissimus dorsi muscles.It originates with strong muscle fibers directly from the medial two-thirds of the infraspinous fossa, whereas its tendinous fibers arise from the ridges of the fossa.Some fibers also originate from the deep surface of the thick … ... Latissimus Dorsi. … It is a powerful extensor muscle of the arm and is used extensively in chinning and climbing. The lattissimus dorsi muscle (sometimes translated as the "broadest muscle of the back") is a flat triangular muscle caudal to scapula. the main action of the Latissimus dorsi is flexion, and the muscle helps your arms move around. Some electrophysiological and morphological properties of 'fast' (singly innervated) and 'slow' (multiply innervated) muscle fibres were studied in normal and denervated posterior and anterior latissimus dorsi muscles of the young chickens. This extensor muscle is responsible for many types of common movements, including pushing yourself up when sitting in a chair. Origin: Spinous processes of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs. Action: Upper fibers elevate the scapula; Middle fibers retract the scapula; Upper and lower fibers rotate the scapula forwards; Latissimus Dorsi: The latissimus dorsi a large, flat muscle on the back and, behind the arm, and is notably covered by the trapezius on the back near the midline. The latissimus dorsi originates from the lower part of the back, where it covers a wide area. The Latissimus Dorsi Muscle Has What Action. It has the same action as teres major. 4 terms. Sharp, stabbing pain and dull aches can usually be felt with any little movement of the back and arms. It has a large, triangular shape and works when you do exercises such as swimming and pull-ups. The muscle assists in holding the scapu… The latissimus dorsi muscle does the following: Adducts the arm at the shoulder.This means that the latissimus dorsi muscle moves the upper arm toward the vertical midline of the body (i.e. Aims and Scope:JPRAS An International Journal of Surgical Reconstruction is one of the world's leading international journals, covering all the reconstructive and aesthetic aspects of plastic surgery.The journal presents the latest surgical procedures with audit and outcome studies of new and established techniques in plastic surgery including: cleft lip and palate and … Action. posterior layer of the thoracolumbar fascia. Latissimus dorsi pain is a discomfort in one of the largest muscles in the back and is often referred to as lat muscle strain. Latissimus dorsi muscle (Musculus latissimus dorsi) The latissimus dorsi muscle (AKA: 'the lats muscle' or 'the lats') is the widest muscle in the human body. The latissimus dorsi also has fibers which attach to the inferior angle of the scapulae and assists in scapular depression and retraction as it performs glenohumeral extension. Page Updated: 04.15.2017 Wide Grip Lat Pulldown Muscles WorkedLatissimus dorsi (lats) The lats keep the shoulders stable. In addition to that, the lats are also responsible for Therefore; exercising the lats muscle is responsible for the adductions ...Posterior deltoids. The posterior deltoids are shoulder muscles. ...Biceps branchii. ...Rhomboids. ...Brachialis. ...Teres major. ... If there are problems with the latissimus dorsi, there could be stiffness in the shoulders and notable spasms behind the shoulder blade. Some electrophysiological and morphological properties of 'fast' (singly innervated) and 'slow' (multiply innervated) muscle fibres were studied in normal and denervated posterior and anterior latissimus dorsi muscles of the young chickens. Latissimus Dorsi. At the elbow joint, the bicep brachii acts as the prime mover of elbow flexion with concomitant Several actions are performed by the latissimus dorsi, all of which involve moving the humerus around the shoulder joint. Innervation. Masseter. A tear of the latissimus dorsi muscle is a discontinuity of muscle or tendon fibers usually at the site of insertion or myotendinous junction. internal rotation following latissimus dorsi tendon transfer, as there are six other muscles of the glenohumeral complex that share the actions of the latissimus dorsi. Suivez toute l'actualité française et internationale avec les News 24/7 2. It therefore acts on the shoulder joint. Latissimi dorsi extend the humeri (pl.) Chin-Ups. Therefore, after the latissimus dorsi is transferred, the teres minor muscle acts in a synergistic manner, compensating for the loss of the latissimus dorsi. It has the same action as teres major. T7-S5 spinous process/tubercles, supraspinous and interspinous…. Thoracodorsal nerve. 2. An action common to the latissimus dorsi, teres major, subscapularis and pectoralis major is _____. The worst (plurality dorsi) comes from Latin and means “broadest [muscle] of the back”, from “latissimus” (Latin: broadest)’ and “dorsum”. Because the amount of skin and other tissue is generally less than in a TRAM flap surgery, this approach may be used for small and medium-sized breasts or for creating a pocket for a breast implant. How To: It can be seen more clearly by cutting away the pectoralis major. Essentially the latissimus dorsi assists in the action of flexion, adduction and internal rotation of the shoulder joint. 1. OBJECTIVE: To determine the morphology of the latissimus dorsi in order to assess its actions on the shoulder, the lumbar spine and the sacroiliac joint. Latissimus dorsi means “widest back muscle” in Latin. The muscle is located in the middle of the back, and it is partially covered by the trapezius. Latissimus Dorsi: The Lats in Action. Due to the scope of latissimus dorsi function, the presence of pain can be attributed to injuries from sports, strenuous exercise, and even common tasks of shoveling. The muscle is also active in violent expiration, as it attaches to the ribs. 51 of 95. For example, when you’re doing a lat pull in a gym, you’re bringing a bar attached to weights to your chest. a thin tendon that twists around and adheres to the lower bord…. Latissimus Dorsi Muscle:. Insertion: The fibers converge into a tendon that attaches to the intertubercular sulcus of the humerus. 2. Extension, adduction, and internal rotation of the humorous . The latissimus dorsi 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. DESIGN: A dissection study accompanied by an analysis of the force vectors of the muscle and its parts. Adducts, extends and internally rotates the arm when the insertion is moved towards the origin. 2. Definition of latissimus dorsi : a broad flat superficial muscle chiefly of the middle and lower back that extends, adducts, and rotates the arm medially and draws the shoulder downward and backward Examples of latissimus dorsi in a Sentence