Category : Anatomy

Anatomy Extensor Tendons Hand Tendons

Anatomy 101: The Extensor Tendon

Tendons are cord-like extensions that connect muscles to bones. Extensor tendons are thin tendons located on the back of the hand, just under the skin. These particular tendons allow you to straighten your fingers and thumb and can be injured by a simple cut or jammed finger. These injuries can cause the tendons to rip from their attachment to the bone, making it hard to straighten your fingers or thumb as you usually do.

Here are two common conditions that result from an injured extensor tendon:

  1. Mallet Fingers are common in baseball players and are typically caused when a ball hits the tip of the finger or thumb. It causes the finger or thumb to droop at the tip.
  2. Boutonnière Deformities are when the middle part of the finger is bent downward.
Read More
Anatomy Bicep Tendon Tear Hand Muscles Tendons

Anatomy 101: The Distal Biceps

The distal biceps muscle is located in the front of your arm (see image above). This muscle helps you to bend your elbow and twist your forearm. Unfortunately, the biceps is prone to injury, especially the biceps tendon, which connects the bicep muscle to the radius bone in your forearm. This tendon can weaken over time, which is called tendonosis. If you have tendonosis of the biceps tendon, you may feel a dull or sharp pain just past the elbow in the forearm. There’s also a chance that you will feel no pain.

Tendonosis can sometimes lead to a tear or rupture in the tendon. Tears or ruptures can happen when you are lifting something heavy such as furniture or weights.

Some signs that you may have torn or ruptured your biceps tendon include:

  • A popping feeling at the time of the rupture or tear
  • Pain in the elbow area
  • Weakness
  • Swelling
  • Bruising
  • Warmth in the elbow area
  • Muscle spasms
Read More
Anatomy Arteries Blood Vessels Hand

Anatomy 101: Arteries of the Arm

There are 5 arteries in the arm and shoulder that supply blood to the body.

Arteries are muscle-lined tubes in the body that transport blood from the heart to other parts of the body. In the upper extremity, there are two arteries that pass through the axilla, also known as the “armpit.” These arteries are:

  • Subclavian Artery: This is the large vessel that begins the blood supply to the upper extremity.  It begins near the heart and travels under the clavicle bone toward the shoulder.  Eventually it turns into the axillary artery.
  • Axillary Artery: This is a continuation of the subclavian artery. This artery travels deep in the arm pit, feeding muscles and bones around the shoulder with its branches. It eventually turns into the brachial artery.
Read More
Anatomy Hand Tendons Wrist

Anatomy 101: Wrist Tendons

Tendons are fibrous cords that are similar to a rope, attached to muscles and bone. The tendons that control movement in your hands, wrists and fingers run through your forearm. There are 6 tendons that help move your wrist. The wrist tendons are:

  • Flexor carpi radialis: This tendon is one of two tendons that bend the wrist.  It attaches to the base of the second and third hand bones.  It also attaches to the trapezium, one of your wrist bones.
  • Flexor carpi ulnaris: This is the other tendon that bends the wrist. It attaches to the pisiform, another wrist bone, and to the 5th hand bone.
  • Palmaris longus tendon:  This tendon is unique because only 3/4 of the population has it. For those who do have it, it can vary in size. It is, however, a tendon you can live without because it has very little function in the hand and wrist. This tendon is often used to repair other tendons since it serves such a small purpose.
Read More
Anatomy Finger Hand Joints

Anatomy 101: Finger Joints

Joints are cartilage surfaces that connect bones to each other. This cartilage allows our bones to glide smoothly against one another, allowing us painless movement. There are four joints in each finger, totaling 20 joints in each hand!

The small, ringer, middle and index fingers all have the same four joints:

  1. Distal Interphalangeal Joint (DIP): The DIP joint is located at the tip of the finger, just before the finger nail starts. Arthritis can develop at this joint, and it is also commonly fractured.
  2. Proximal Interphalangeal Joint (PIP): The PIP joint is the joint just below the DIP joint. It is located below the top two bones of the finger and allows the finger to bend and extend. This joint can become stiff easily after injury.
  3. Metacarpophalangeal Joint (MCP): The MP joint is where the hand bone meets the finger bone, referred to as the “knuckle.” These joints are very important, allowing us to bend/flex and spread our fingers.
  4. Carpometacarpal Joint (CMC Joint): The CMC joint is located at the bottom of the hand bone. This joint varies in each finger. For example, in the index finger, it has little motion. In the small finger, it has a lot of motion. Injuries and problems with this joint are uncommon.

The thumb joints are a little different than the other finger joints. To learn more about the thumb joints and more about the finger joints, visit our online Anatomy section.

Read More
Anatomy Bones Shoulder

Anatomy 101: Shoulder Bones

There are five major bones in the shoulder. The shoulder bones can easily be affected by falls or accidents, in addition to arthritis. Here is an overview of the shoulder bones:

  1. Scapula: Another name for this bone is the shoulder blade. There are 17 muscles that attach to the scapula! Much of your shoulder motion is between the scapula and the chest. The scapula is part of the “shoulder girdle” which also includes muscle and ligament that allow your shoulder to move.
  2. Clavicle: This bone is also referred to as the collar bone. The clavicle connects the arm to the chest. It has joints on both ends, which can become arthritic.
  3. Acromion: This bone is a flat projection of the scapula that gives the shoulder its square shape.
  4. Coracoid Process: This bone is also a projection of the scapula. It points outward toward the front of the body. This bone is important because its muscles and ligaments help support the clavicle, shoulder joint and humerus.
  5. Glenoid Cavity: This is the socket portion of the ball-and-socket joint of the shoulder. Any abnormalities in the cavity can cause joint instability, which can lead to a condition called “frozen shoulder.”

Learn more about the shoulder bones and the anatomy of the upper extremity (including the hand, wrist, arm and shoulder) at www.HandCare.org/hand-arm-anatomy.

Read More
Anatomy Forearm Muscles Wrist

Anatomy 101: Wrist Muscles and Forearm Muscles

The wrist muscles and forearm muscles do so much more than give you strength in your arm and wrist. These muscles also play a part in helping you move your hand and fingers. There are 18 different muscles!

Here’s a preview of these muscles:

  • Flexor pollicis longus: Helps you bend the tip of your thumb.
  • Flexor digitorum profundus: Helps you bend your index, middle, ring and small fingers.
  • Flexor digitorum superficialis: Helps you bend the middle joint of each finger, except for the thumb, which allows you to do things such as eating with chopsticks.
  • Flexor carpi ulnaris: Helps you move your wrist away from the thumb, which is helpful in playing darts.
  • Brachioradialis: Helps you twist your forearm so your palm is either facing up or down.
  • Flexor carpi radialis: Helps you bend the wrist and move it toward the thumb.
  • Palmaris longus: Helps you bend the wrist.
  • Extensor pollicis brevis: Helps you straighten the thumb.

To learn more about all 18 muscles, visit our wrist and forearm muscles page on www.HandCare.org.

Read More
Anatomy Bones Joints Wrist

Anatomy 101: Wrist Joints

The wrist joints lie between the many different bones in the wrist and forearm. Many wrist injuries (such as fractures, also known as a broken bone) involve the joint surface. There are three joints in the wrist:

  1. Radiocarpal joint: This joint is where the radius, one of the forearm bones, joins with the first row of wrist bones (scaphoid, lunate, and triquetrum).
  2. Ulnocarpal joint: This joint is where the ulna, one of the forearm bones, joins with the lunate and triquetrum wrist bones. This joint is commonly injured when you sprain your wrist. Some people are born with (or develop) an ulna that is longer than the radius, which can cause stress and pain on the joint, known as ulnocarpal abutment (impaction) syndrome.
  3. Distal radioulnar joint: This joint is where the two forearm bones connect. Pain with this joint can sometimes be a challenging problem to treat.

Learn more about the joints of the wrist and also the bones of the wrist in our Anatomy section. You can also visit www.HandCare.org for information on conditions and injuries of the hand, wrist, arm and shoulder.

Read More
1 2 3