Thenar. The thenar muscle group is found at the base of the thumb, forming the muscle bulk on the thumb side of the hand. It is comprised of three muscles: the abductor pollicis brevis, the flexor pollicis brevis, and the opponens pollicis.
Thenar eminence - fleshy part at the base of the thumb, made up of 3 muscles which control the movements of the thumb.
Thenar and hypothenar are two terms that describe the fleshy mass of skin, fat, and muscle on the thumb side (radial) and the small finger side (ulnar) of the hand.
The thumb digit has only two phalanges (bones) so it only has one joint. The thumb interphalangeal (IP) joint is similar to the distal interphalangeal (DIP) joint in the fingers. The IP joint in thumb is located at the tip of the finger just before the fingernail starts.
The thenar muscles are a group of three muscles that act on the thumb. These muscles form the bulge on the palmar surface of the thumb and palm, called the thenar eminence.
Overuse is the likeliest cause. Inflammation can arise from repeated hand and thumb motions like lifting with the thumb up, squeezing, pinching, gripping and wringing. Scar tissue from an injury or surgery may narrow the tendon's tunnel, increasing the risk of thumb tendonitis.
Triphalangeal thumb (TPT) is a congenital malformation where the thumb has three phalanges instead of two. The extra phalangeal bone can vary in size from that of a small pebble to a size comparable to the phalanges in non-thumb digits.
Each of the flexor tendons to the fingers and thumb passes through a separate tubular structure, called a tendon sheath, as the tendon makes its way across the palm and into the digit. The tendon sheaths are firmly attached to the finger or thumb bones.
Volar: in the same plane as the pulp of the thumb. Ulnar: on the side of the thumb toward the hand at a right angle to the plane of the thumbnail. Radial: on the side of the thumb away from the hand at a right angle to the plane of the thumbnail.
The first dorsal interosseous muscle is the largest and originates from the 1st and 2nd hand bones. It forms the contour between the thumb and index finger when looking at the top of the hand and is often the first muscle to shrink in patients with severe cubital tunnel syndrome due to damage of the ulnar nerve.
In the hand the space between the deep flexor tendons and the interosseous fascia is named the midpalmar space, spatium palmare medianum. A fat body, Corpus adiposum palmare profundum, can be found there regularly. Despite the anatomical narrowness in this region, it reaches up into the carpal canal.
The area of skin between the thumb and the index finger is often call the "thenar webspace". What the "webspace" looks like when a child is performing fine motor tasks is often a good indicator of muscle strength and fine motor control.
The thenar eminence is the fleshy mound at the base of the thumb. The hypothenar eminence is the mound located at the base of the fifth digit (little finger). The eminences at either side of the hand are made up of muscles. The muscles located in the thenar eminence function primarily to control the thumb.
*Flagina -the awkward piece of skin between your thumb and pointer.
Radial bursa
Immediately adjacent and deep to FCR in the carpal tunnel is the flexor pollicis longus (FPL) tendon synovial sheath. The FPL tendon flexes the distal phalanx of the thumb. This tendon sheath is sometimes referred to as the radial bursa.
De Quervain's tenosynovitis is swelling of the tendons that run along the thumb side of the wrist and attach to the base of the thumb. This occurs when the tendons are constricted by the sheath that they run through to get from the wrist to the hand.
Most thumb sprains involve the ulnar collateral ligament (UCL), which is located on the inside of the joint where the thumb meets the palm. An injury to this ligament can be painful and may make your thumb feel loose or unstable.
The thumb joint, called the carpometacarpal joint, is made up of a bone in your wrist called the trapezium, and a long bone at the base of your thumb called a metacarpal.
The most commonly injured ligament in the thumb is the ulnar collateral ligament (UCL). An injury to this area may go by a few different names: gamekeeper's thumb, skier's thumb, and break-dancer's thumb. If you completely tear your UCL, you will need surgery to repair it.
In the thumb, the most common site for arthritis to develop is in the basal joint at the base of the thumb — also known as the thumb carpometacarpal (CMC) joint. Although there are several types of arthritis, the one that most often affects the basal joint is osteoarthritis (degenerative, or wear-and-tear, arthritis).
The most common symptom of thumb basal joint arthritis is a deep, aching pain at the base of the thumb. The pain is often worsened with activities that involve any pinching movements such as opening jars, turning door knobs, and handwriting. As the disease progresses, patients may experience pain at rest and at night.
Apply cold. Icing the joint for five to 15 minutes several times a day can help relieve swelling and pain. Apply heat. For some, heat may be more effective than cold in relieving pain.
By stage IV, bone spurs, narrowed joint space, and even joint dislocation may be seen. Although X-rays are important, radiographic staging of the disease does not predict the severity of symptoms or guide treatment.