10.1 Muscles, Bones, and Nerves of the Fingers, Hands, and Arms

Bones of the Fingers, Hand, and Forearm

This section covers Pearson VUE February 2026 outline item III.A.1. Names and counts below are standard nail-technology instruction. Under 49 Pa. Code § 7.1, nail technology includes massaging the hands, or massaging the lower arms up to the elbow. The stroke may reach the elbow. It does not continue onto the upper arm or the shoulder.

Wrist, palm, and finger bones

One hand has 27 bones in three groups: 8 carpals in the wrist, 5 metacarpals in the palm, and 14 phalanges. The thumb has 2 phalanges and no middle phalanx. Each of the four fingers has 3: proximal, middle, and distal. The nail plate rests on the distal phalanx, so the stroke works the soft tissue around that bone.

From the thumb side, the carpal row nearer the forearm is the scaphoid, lunate, triquetrum, and pisiform. The row nearer the palm is the trapezium, trapezoid, capitate, and hamate. Use those names as landmarks for thin padding. A glide may cross the wrist. Firm pressure only presses skin against bone.

Metacarpals are numbered from the thumb. The first is in the thumb, and the fifth is on the little-finger side. Their heads are the knuckles. Joints between phalanges sit farther out and also take light contact. Glide along the shafts, and lighten the stroke over a knuckle.

The two forearm bones

The radius is the forearm bone on the thumb side, and it meets the wrist on that side. The ulna is the forearm bone on the little-finger side, and its upper end forms the point of the elbow. A stroke may follow either bone and stops at the elbow. In order, the hand crosses the phalanges, the knuckles, the palm, and the wrist, then the forearm. The biceps is above the elbow. A nail technician does not treat the biceps as part of nail technology, and shoulder massage is outside this service.

Muscles Below the Elbow

The thenar group is the mound at the base of the thumb, the padding used to pinch and to draw the thumb toward the fingers. Knead the soft center, not the first metacarpal.

The hypothenar group is the narrower mound at the base of the little finger. Knead the soft tissue, and lighten the stroke where the fifth metacarpal is easy to feel.

The forearm flexors lie on the palm side of the forearm and bend the wrist and fingers. With the palm up, glide from the fingers toward the elbow and stop there, even if the muscle belly seems to continue.

The forearm extensors lie on the back-of-hand side of the forearm. Their tendons cross the back of the hand and straighten the wrist and fingers. With the palm down, pressure stays lighter because that padding is thin.

Muscle names the textbooks use

Standard nail-technology instruction also names hand and forearm muscles by what they do. The abductors separate the fingers. The adductors draw the fingers together. The opponens muscles in the palm bring the thumb toward the fingers, the grasping motion, and much of that work sits in the thenar mound. In the forearm, the pronator turns the hand inward so the palm faces down, and the supinator turns it outward so the palm faces up. The flexors bend the wrist and fingers, and the extensors straighten them.

Three upper-arm muscles are named so you can recognize the boundary, not so you can massage them. The biceps covers the front of the upper arm, lifts the forearm, and bends the elbow. The triceps covers the back of the upper arm and extends the forearm. The deltoid caps the shoulder and lifts the arm. All three sit above the elbow, so they are outside nail technology massage under § 7.1. The humerus is the single upper-arm bone, running from the shoulder to the elbow. Its lower end meets the radius and the ulna at the elbow, which is where the manicure stroke stops.

Nerves and What Tingling Means

The median nerve covers the palm side of the thumb, index finger, middle finger, and the thumb-side half of the ring finger. Tingling in that pattern is a reason to lighten pressure. It is not a diagnosis of carpal tunnel syndrome, and the technician does not invent a treatment for the sensation.

The ulnar nerve covers the little finger and the other half of the ring finger. It passes close to the surface on the little-finger side of the elbow, so a bump there is felt in the little finger. Do not press that spot, and do not travel above the elbow.

The radial nerve runs along the thumb side of the forearm and supplies much of the back of the hand, where tendons and bone sit under thin skin. Keep rubs and taps light on that surface.

The digital nerves branch from those three nerves and run along the sides of each finger to the fingertip. They lie close to the skin at the sidewalls, which is one reason a nick at the fold hurts and why a fingertip squeeze stays gentle.

For any of these patterns, reduce pressure and keep the work on the hand and the lower arm.

Four Movements on Hand Tissue

Effleurage is a gliding stroke from the fingertips toward the elbow. It crosses the flexors with the palm up and the extensors with the palm down, and it stops at the elbow.

Petrissage is kneading for the thenar group, the hypothenar group, and the soft forearm. It does not belong on the carpals, where the hand would only press bone.

Friction is a small circular rub for the palm and the bases of the fingers. Over a knuckle or the wrist, the circle stays light and moves the skin.

Tapotement is tapping. Light fingertip taps may land on the fleshy palm or the padded forearm, not on the wrist bones or the ulnar nerve at the elbow.

Where the stroke stops

A client asks for more massage because the shoulder feels tight. Effleurage has just reached the elbow on the flexor side. The technician stops there. Under 49 Pa. Code § 7.1, massage of the lower arm goes up to the elbow, so the upper arm and the shoulder are outside the service. The finish is a lighter glide back toward the fingers, still light over the ulnar nerve. If the little finger tingles, contact gets lighter still. The biceps is not added.