DEFINITION OF GONIOMETER

The instrument, which is used for measuring the range of motion of the joint, is called as goniometer.

The term goniometry is derived from the Greek words Gonio-Angle and Metron-Measurement.

To measure a range of motion of a particular joint the therapist should have the thorough knowledge on the range of motion of an individual joint, types of range of motion, osteo and arthrokinematic of the joint and axis and plane of the joint.

 

TYPES OF GONIOMETER

1. Universal goniometer or Goniometry

2. Gravity dependent goniometer or fluid goniometer

3. Pendulum goniometer

4. Electrogoniometer

 

1. Universal Goniometer

It is designed by Mr. Moore. This is very commonest variety. It is having stationary arm, movable arm, and body.

 

Body

Body of the goniometer resembles like half or full circle protractor. Normally, the half circle protractor contains 0° to 180° or 180° to 0 of readings and the full circle protractor body consists of 0° to 360° and 360° to 0° readings. In the middle of the body axis and fulerum serew movable armn. This axis of the goniometer is present, it connects the stationary and placed over the axis of the joint, which has to be measured.

Stable Arm

This is the extension from the body of the goniometer. The stable arm does not have any motion. This will be aligned with the proximal segment of the measuring joint.

Movable Arm

This is the additional attachment with the body of the goniometer in the axis. Movable arm is aligned with the distal segment of the mea- suring joint.

2. Gravity Dependent Goniometer or Fluid Goniometer

It is otherwise called as pelvic inclinometer, it is designed by Schenkar in 1956. It is having gravity effecting pointer and the fluid filled chamber with the air bubbles. It resembles like the carpenter's level meter. It is mostly used for measuring the pelvic tilt or drop.

3. Pendular Goniometer

It is designed by Fox and Van breemnen in 1934. It consists of 360° protractor with the weighed pointer.

4. Electrogoniometer

It is designed by Karpovich and Karpovich in 1959, it has two arms. One is attached with the proximal segment and another is attached with the distal segment of the measuring joint. The potentiometer is connected with these two arms. Changes in the joint position show the angulations in the potentiometer. It is mostly used for the research purposes.

PROCEDURE

Patient's clothes are removed where the joint measuremnent to be taken. Position the patient in the relaxed manner and the joint to be measured should be free from any obstructions like pillow, couch, etc. Measuring joint has to be in 0° position. Total procedure should be explained to the patient. * Therapist has to stand near to the patient and facing the joint, which has to be measured. 41 Axis or the fulcrum of the goniometer is placed over the axis of the joint to be measured. Stable arm is fixed with the proximal seg- ment of the joint. Movable arm is fixed with the distal segment of the joint. Therapist has to move the distal segment of the joint with the movable arm of the goniometer to measure the joint range.

 

SELECTION OF THE GONIOMETER

Selection of the goniometer is much more important factor while measuring the range of motion of the joint. If the bony segments of the joints are big, the bigger size, i.e. bigger length movable and stable armed goniometer has to Normally, the inclinometer is mostly used to be used and for the smaller segment vise versa. measure the pelvic motion.

POSITION OF THE PATIENT

Position of the patient is another factor has to be noticed carefully while measuring the joint range with the goniometer. Proper positioning of the patient itselfis the competition of half of the procedure of measuring the joint range. To measure the range of motion of one particular joint, the below mentioned factors has to be followed. The joint structures have to be in relaxed manner. Joint should be in zero or starting position. The complete range of motion of the joint has to be permitted. Proximal joint has to be fixed or stabilized There is no proper recommended position to measure the range of motion with the gonio- meter. It may vary depends on the creativity of an examiner. Only thing is, it should fulfill the above said condition with the convenient position for the patient as well the therapist.

FACTORS AFFECTING THE JOINT RANGE OF MOTION

Soft Tissue Tightness

Joint soft tissues like muscle, ligament, capsule, cartilage, synovial membrane spasm or tight- ness causes the reduction of range of motion of the joint. The soft tissue tightness may be due to the prolonged immobilization of the joint, injury around the joint or any joint diseases like osteoarthritis, rheumatoid arthritis, ankylosing spondylitis and TB arthritis.

Adhesion Formation

Adhesion formation of the joint reduces the ROM of the joint. Lack of mobility of the joint leads to reduction in the flexibility and the nourishment circulation around the joint struc- tures. If the joint structures are immobilized for prolonged period reduces the extensibility, formation of the adhesion and formation of the contraction of the soft tissue around the joint. There will be increasing of the collagen fibers and reduction of the elasticity property of the fibers of the connective and soft tissues of the joint.

Injuries or Inflammation around the Joint

Any recent injuries, inflammatory condition and the joint diseases like osteoarthritis, rheumatoid arthritis, ankylosing spondylitis and TB arthritis and psoriatic arthritis may cause severe pain around the joint. As the result of the pain patient may avoid performing the full range of movement. Sometimes due to fear of pain also patient many not perform any movement. So, as a result, there will be reduction in the active and passive range of movement.

Muscle Bulk

Increasing the muscle bulk may cause the reduction of the active and passive range of motion. For example, for a common man the elbow flexion range of motion will be 125° to 135° but it is very much lower for the body. builders due to their huge biceps muscle bulk

Sex

The range of motion may vary with the sex. For example, females will be having less hip extension and hyper hip flexion after 25 years, but the same is reverse in male. Generally. female will be having the more flexible increa- sed range of motion than the male.

Age

The range of motion of joint will be more in the infant and childhood due to nonfusion of the bones. Day by day the range of motion reduces with the age difference. While reaching the adulthood, the range of motion reduces while comparing with the childhood and late childhood. The range of motion again bit increases in the old age due to the hypotonicity of the muscles and the reduction of the muscle bulk.

Nervous System

Sometimes the range of motion may vary with the pathological changes, i.e disease process in the nervous system. Spasticity of the muscle, which is the result of the UMN lesion, will be reducing the range of motion and the joint said to be hypomobile. The LMN lesion, which causes the flaccidity, will result in hypermobile joint. If the musculoskeletal disorder arises due to the lesion of any parts of the nervous systen like cerebellum, basal ganglion, cerebral cor- tex, thalamus, hypothalamus, internal capsule, midbrain and pons result in the decreasing or increasing the range of motion.

MEASURING PROCEDURES

Shoulder Joint

Flexion

Position of the patient: Supine lying. Axis: Greater tuberosity of the humerus is taken as the axis. Movable arm: Movable arm is placed over the midline of the lateral aspect of arm and is holding by the therapist's right hand. Stable arm: It is placed straight line to the movable arm and is kept in the air without the patient's body contact and is holding by the therapist's left hand. Procedure: Therapist's right hand is per- forming the flexion movement of the shoul- derjoint with the goniometer and measuring the angle to see the passive range of motion and the active ROM is measured by patient himself performing the movement.

Extension

Position of the patient: Prone lying. Axis: Greater tuberosity of the humerus is taken as the axis. Movable arm: Movable arm is placed over the midline of the lateral aspect of arm and is holding by the therapist's left. hand. Stable arm: It is placed straight line to the movable arm and is kept in the air without the patient's body contact and is holding by the therapist's right hand.

Procedure

Therapist's left hand is performing the extension movement of the shoulder joint with the goniometer and measuring the angle to see the passive range of motion and the active ROM is measured by patient himself performing the movement.

Abduction

Position of the patient: Supine lying.

Axis: One inch below the acromion process of the scapula is taken as the axis.

Movable arm: Movable arm is placed over the midline of the anterior aspect of arm and is holding by the therapist's right hand.