The term goniometry is derived from two Greek words, gonia meaning angle and metron,
meaning measure. Thus, a goniometer is an instrument used to measure angles. Within
the field of physical therapy, goniometry is used to measure the total amount
of available motion at a specific joint. Goniometry can be used to measure both
active and passive range of motion. Goniometers are produced in a variety of sizes
and shapes and are usually constructed of either plastic or metal (see clip labeled
Gonio_introduction). The two most common types of instruments used to measure
joint angles are the bubble inclinometer and the traditional goniometer.
Bubble goniometer. The bubble goniometer, which has a 360° rotating dial
and scale with fluid indicator can be used for flexion and extension; abduction
and adduction; and rotation in the neck, shoulder, elbow, wrist, hip, knee,
ankle, and the spine.
Traditional goniometer. The traditional goniometer, which can be used for
flexion and extension; abduction and adduction; and rotation in the shoulder,
elbow, wrist, hip, knee, and ankle, consists of three parts:
A body. The body of the goniometer is designed like a protractor and may
form a full or half circle. A measuring scale is located around the body.
The scale can extend either from 0 to 180 degrees and 180 to 0 degrees for
the half circle models, or from 0 to 360 degrees and from 360 to 0 degrees
on the full circle models. The intervals on the scales can vary from
1 to 10 degrees
A stationary arm. The stationary arm is structurally a part of the body
and therefore cannot move independently of the body
A moving arm. The moving arm is attached to the fulcrum in the center
of the body by a rivet or screw-like device that allows the moving arm to
move freely on the body of the device. In some instruments , the screw-like
device can be tightened to fix the moving arm in a certain position or loosened
to permit free movement.
The correct selection of which goniometer device to use depends on the joint angle
to be measured. The length of arms varies among instruments and can range from
3-18 inches. Extendable goniometers allow varying ranges from 9 ½ inches to 26
inches (see clip labeled Gonio_introduction). The longer armed goniometers, or
the bubble inclinometer are recommended when the landmarks are further apart,
such as when measuring hip, knee, elbow, and shoulder movements. In the smaller
joints such as the wrist and hand and foot and ankle, a traditional goniometer
with a shorter arm is used.
The patient is positioned in the recommended testing position. While stabilizing
the proximal joint component, the clinician gently moves the distal joint component
through the available range of motion until the end feel is determined. An estimate
is made of the available range of motion and the distal joint component is returned
to the starting position. NB: In the accompanying videos, it is assumed that the
procedure up until this point has been completed.
The clinician palpates the relevant bony landmarks and aligns the goniometer.
A record is made of the starting measurement. The goniometer is then removed and
the patient moves the joint through the available range of motion. Once the joint
has been moved through the available range of motion, the goniometer is replaced
and realigned, and a measurement is read and recorded.
Active ranges of motion of the larger joints