Use the filters on the left to identify muscles around a particular joint as well as for specific joint actions. Click on the links below for more detailed explanations including origins, insertions and related sports injuries.
Adductor Brevis is the smallest and shortest of the three short adductor muscles. It originates on the pelvis and inserts into the thigh bone and adducts inwards and flexes the hip out forwards. It is most commonly injured in a groin strain.
Adductor Longus is the middle of the three short adductor muscles. It adducts the hip inwards and assists in hip flexion or moving the leg forwards. Originating on the ramus of the pelvis and inserts into the femur or thigh bone.
Adductor Magnus is the largest groin muscle and is one of the two long adductor muscles (gracilis is the other). It is usually described as having two parts, hamstring and adductor parts. It adducts, flexes and internally rotates the hip.
The Anconeus works alongside Triceps Brachii in extending the elbow. It also acts to pull the synovial membrane out of the way of the olecranon process when the elbow is extending.
The Biceps brachii crosses both the elbow and shoulder joints. Its action on the shoulder joint is very weak flexion. It supinates the forearm and is a strong flexor of the elbow. The bicep curl exercises is a common one to strengthen this muscle.
Biceps Femoris is one of the three muscles which form the hamstring group forming the back of the thigh. The muscle is described as having a long head (the attachment from the ischium) and a short head (attached to the femur).
The Brachialis acts to flex the elbow whether in pronation or supination, along with Biceps Brachii. As Brachialis is attached to the Ulna, which cannot rotate, it is the only true flexor of the elbow.
The Brachioradialis muscle flexes the elbow and supinates the forearm from a pronated position and pronates from a supinated position.
The deltoid muscle is used in all side lifting movements and any movement of the humerus on the scapula.
The erector spinae (sometimes known as sacrospinalis) is often described as a group of different muscles called iliocostalis, longissimus and spinalis.
The extensor carpi radialis brevis muscle extends and abducts the wrist and is a weak extensor of the elbow.
The extensor carpi radialis longus muscle extends and abducts the wrist and is a weak extensor of the elbow.
Extensor carpi ulnaris is located on the back (dorsum) of the forearm. It extends and adducts the wrist and weakly extends the elbow.
Extensor digitorum longus (often shortened to EDL) is found in the front of the lower leg, in the outer more muscle bound compartment.
The extensor hallucis longus is the only muscle responaible for extending (pulling back) the big toe, dorsi flexes the ankle and weakly inverts the foot.
The obliques wrap around the trunk on each side to form our waists and join to the linea alba, a band of connective tissue running down the front of the abdomen.
The flexor carpi radialis muscle flexes and abducts the wrist and is a weak flexor of the elbow.
The flexor carpi ulnaris muscle flexes and adducts the wrist as well as being a weak flexer of the elbow.
Flexor Digitorum Longus causes the toes to grip and mold to the floors surface which is vital in maintaining balance on rough surfaces.
The flexor digitorum superficialis muscle flexes or bends the fingers, flexes the wrist and is a weak flexor of the elbow.
Flexor Hallucis Longus bends the big toe when you curl up your foot. It is called 'Hallucis' as the word Hallux means great or big toe in latin.
The flexor pollicis longus muscle lfexes the thumb and wrist and is a weak flexor of the elbow.
Gastrocnemius muscle is a strong plantar flexor of the ankle and weakly flexes the knee.
Gluteus Maximus is the largest and most superficial of the three gluteal muscles which forms the rounded shape of the buttocks.
Gluteus Medius is an important muscle in controlling the level of the hips. Weaknesses in gluteus medius often result in a trendelenburg sign, an abnormal gait cycle.
This is the smallest of the three gluteal muscles. It abducts the hip and assists with internal rotation as the femur abducts.
Gracilis is another muscle which works in conjunction with the groin muscles and is also a weak knee flexor.
The groin muscles are sometimes also call the 'adductor's. This describes the movement that they all perform. There are five adductors in total.
The hamstring muscles are found at the back of the thigh. They are three muscles which act on both the hip and knee joints.
A powerful hip flexor, also assists in externally rotating the femur.
Infraspinatus is one of the rotator cuff muscles. It sits on the back of the shoulder blade, below the spine of the scapula and attaches to the greater tuberosity on the humerus.
The internal obliques wrap around the waist and insert into the linea alba, a cord like strip of connective tissue running down the centre of the abdomen.
The Latissimus dorsi muscle is one of the largest in the body. It is a powerful extensor muscle of the arm and is used extensively in chinning and climbing.
Shrugging the shoulders (scapula elevation) requires the use of levator scapulae and Trapezius.
Multifidus is a series of small muscles which travel up the length of the spine. It is an important muscle in the rehabilitation of Gilmore's Groin and lower back pain.
Pectineus is positioned between the Iliopsoas and Adductor Longus muscles and is part of the short adductor group with adductors brevis and longus.
Pectoralis major is the largest and most superficial of the chest muscles, Its action depends on the position of the arm.
The Pectoralis Minor muscle is the smallest of the two pectoral (chest) muscles. It works together with Serratus anterior which protracts and rotates the scapula upwards.
Peroneus Brevis everts (turn outwards) the foot and plantar flex the ankle.
Peroneus Longus is one of the peroneals muscle group which pass down the outside of the lower leg and evert (turn out) the foot.
The Piriformis muscle is an important muscle. The sciatic nerve passes underneath this muscle on its route down to the posterior thigh.
Popliteus is a small muscle which is often described as the key of the knee joint. It unlocks the knee joint by rotating the femur at the beginning of knee flexion to allow full knee flexion to occur.
Pronator Quadratus works in conjunction with Triceps Brachii during pronation with elbow extension.
Pronator Teres works the hardest when the elbow is flexing and the hand simultaneously pronating.
The quadratus lumborum or QL is a common cause of back pain which is to one side and comes on after lifting or twisting.
Quads (Quadriceps Muscles)
Rectus Abdominis is the most superficial of the abdominal muscles. It is this muscle which forms the six-pack shape!
The Rectus Femoris muscle is part of the Quadriceps muscle group. It is the only muscle of the group which crosses the hip joint and so it flexes the hip whilst extending the knee.
There are two rhomboid muscles - Rhomboid Major and Rhomboid Minor. Rhomboid major is larger and positioned below rhomboid minor.
The Sartorius is a two joint muscle and so is weak when the knee is flexed and the hip is flexed at the same time. It works better during single movements.
Semimembranosus is the most medial of the three hamstring muscles. It extends and internally rotates the hip and flexes the knee.
The semitendinosus muscle extends and internally rotates the hip as well as flexing the knee.
The Serratus Anterior muscle is used in activities which draw the scapula forwards. It is used strongly in push-ups and bench presses.
Soleus is a large large muscle, deep to Gastrocnemius. Together the Gastrocnemius, Soleus and Plantaris are known as Triceps Surae.
Splenius is often divided into two muscles, splenius capitus (those fibres which insert on the skull) and splenius cervicis (those that insert onto the cervical transverse processes of the spine).
Sternocleidomastoid (SCM) can clearly be seen when you turn your head to one side, on the opposite side of the neck.
Subscapularis is one of the four rotator cuff muscles which cross the shoulder joint. The muscle also acts to hold the head of the humerus in position and prevents it moving forwards.
The Supinator muscle assists Biceps Brachii in supinating the hand, that is turning it over so that the palm faces up.
The Supraspinatus muscle is one of the four muscles which make up the rotator cuff. Its main function is to stabilise the upper arm by holding the head of the humerus in position.
The Tensor Fasciae Latae (TFL) is a small muscle which attaches inferiorly to the long thick strip of fascia, known as the iliotibial band (ITB).
Teres Minor is one of the four rotator cuff muscles surrounding the shoulder. Its main action, along with Infraspinatus is to externally rotate the shoulder joint.
The 'Glutes' is an abbreviation of the gluteals - also known as the buttock muscles. The three main ones are the Gluteus Maximus, Medius and Minimus.
Tibialis anterior forms the main fleshy part of the outside of the shin. It is a dorsiflexor of the ankle.
The Tibialis Posterior is the deepest of all the calf muscles. It helps to support the arch of the foot.
Transversus Abdominis is often abbreviated to TVA. This is a very important core muscle which is vital in maintaining good posture. Activities such as Pilates focus on contraction of the TVA.
The trapezius muscle (Trapz) is a large muscle consisting of four parts covering the upper back, shoulders and neck.
The Triceps Brachii also assists Latissimus Dorsi in extending the shoulder joint. It contracts strongly during the up phase of a push up, to straighten the arm.
Vastus Intermedius is one of four quadricep muscles, located deep in the thigh underneath the Rectus Femoris muscle.
Vastus Lateralis is the most lateral (outer) of the four quadriceps muscles and is felt on the outside top of the thigh.
Vastus Medialis is the most medially (inner) located of the quadricep muscles. The portion of the muscle just above the knee is known as VMO (vastus medialis oblique).