What Is a Pivot Joint?

Joint mobility refers to the arc of movement or the angle of rotation through which the joint moves. Joint mobility is divided into active joint mobility and passive joint mobility. The former is generated by active contraction of muscles, and the latter is generated by external forces. There is no free movement of muscles. During forensic evaluation, when measuring the active and passive ROM of the joint, attention should be paid to the comparison on both sides, with the joint starting position as the neutral position of 0 °, such as elbow motion: 0 ° extension (neutral position), 140 ° flexion. (Shen Yiwen) ^[1]

Joint mobility

Joint mobility refers to the arc of movement or the angle of rotation through which the joint moves. Joint mobility is divided into active joint mobility and passive joint mobility. The former is generated by active contraction of muscles, and the latter is generated by external forces. There is no free movement of muscles. During forensic evaluation, when measuring the active and passive ROM of the joint, attention should be paid to the comparison on both sides, with the joint starting position as the neutral position of 0 °, such as elbow motion: 0 ° extension (neutral position), 140 ° flexion. (Shen Yiwen) ^[1]

The measurement of the range of motion of the joint is to evaluate the muscle,

Common causes of abnormal range of motion include: joints,

Specific contents of the evaluation of joint mobility (ROM)

Tools and rules for ROM evaluation

ROM measurement

I. Measurement tools:

Protractor, spinal activity measurement (tape measure).

Measurement method

1. Comfortable posture 2. Exposure measurement of joints

3. Determine the bony landmarks of the measurement joint

4. Special person measurement 5. Active joint activity measurement, passive joint activity measurement (positioned by scribing).

6. Correctly locate the motion axis, fixed arm, and mobile arm

3. Recording of measurement results

Content: joint name, left and right, active ROM, passive ROM, joint ankylosis (fibrous, bony), contracture, spasm, etc.

Section 3 ROM Measurement Method

First, the spine

(1) Cervical spine ROM

1.Neck flexion 0 °-45 °

2.Neck extension 0 °-45 °

Position: Sit or upright Axis: Mandibular angle Fixed arm: Shoulder

3.Neck flexion 0 °-45 °

Posture: Sit or upright Axis: Seventh cervical spinous process Fixed arm: On shoulders

4.Neck rotation 0 °-45 °

Position: supine axis: overhead fixed arm: flat bed surface

(B) Thoracic and Lumbar ROM

1.Spine flexion 0 ° -80 °

Position: Upright Axis: L5 Spinous process Fixed arm: Body side midline

Motion measurement: angle, distance of the fingers from bending to the ground, the length of the first condylar vertebra of the seventh cervical spinous process when bending over, 1.6CM

Scoliosis 0 ° -40 °

Position: Upright Axial: S1 Fixed Arm: Dorsal Midline

Motion measurement: angle, distance between fingertip and knee joint when flexing laterally

3.Spine extension 0 ° -30 °

Position: Upright Axial Center: S1 Fixed Arm: Body Side Midline

4.Spine rotation 0 ° -45 °

Position: supine or uprightAxial center: overhead fixed arm: flat bed surface

Second, upper limb ROM

(A) shoulder joint

Anatomy and Kinematics Overview

The shoulder bones include the humerus, clavicle, scapula, sternal bone, and chest wall, which constitute six shoulder joints: glenohumeral, acromioclavicular, sternoclavicular, sacral, humeral, and scapular chest wall joints. The glenohumeral joint is the joint with the largest range of motion throughout the body. It can perform flexion and extension, adduction, abduction, internal rotation, and external rotation movements on three planes around three motion axes.

The movements of the shoulder are mainly coordinated and coordinated by the four joints of the glenohumeral, sternoclavicular, acromioclavicular, and scapula chest wall. Anterior flexion 60 & ordm ;, abduction 30 & ordm ;, completed by the glenohumeral joint, and later movements are participated by the scapular chest wall joint, the exercise ratio is 2: 1.

1.Shoulder joint flexion 0 ° -180 °

Position: Sitting or supine Axis: Acromion Fixed arm: Body side midline

2, shoulder joint extension 0 ° -60 °

Axis: Shoulder Peak Fixed Arm: Body Side Midline

3.Shoulder abduction 0 ° -180 °

Posture: Sitting or prone position Axis: Acromion Fixed arm: Midline of upper back arm

4. Horizontal abduction of shoulder joint 0 ° -40 °

Position: sitting axis: acromion fixed arm: acromion to back of neck

5.Adduction of shoulder joint horizontally 0 ° -130 °

Position: Sitting or supine Axis: Acromion Fixed arm: Acromion to back of neck

6. Shoulder joint abduction and internal rotation 0 ° -70 °

7. Shoulder joint abduction external rotation 0 ° -90 °

B) Elbow joint

1) Anatomy and Kinematics

Brachio-ulnar joint: The main part of the elbow joint, performing flexion and extension exercises.

Brachioradial joint: assist in the movement of the proximal radioulnar joint.

Proximal ulnar joint: complete forearm pronation and supination.

2.Elbow extension-flexion 0 ° -135 ° / 150 °

Position: sitting axis: humerus epicondyle fixed arm: upper arm midline

3.Forearm swivel 0 ° -80 ° / 90 °

Position: sitting axis: axis of ulna styloid process fixed arm: perpendicular to the ground

4.Forearm pronation 0 ° -80 ° / 90 °

Position: sitting axis: axis of ulna styloid process fixed arm: perpendicular to the ground

(Three) wrist ROM

Anatomy and Kinematics

The wrist joint is composed of the radius, distal ulna, and 8 wrist bones. Narrow sense: radial wrist joint. Broadly defined: radial wrist, intercarpal bone, distal radius ulnar joint. The radial wrist joint can perform four kinds of exercises: palmar flexion, dorsiflexion, ulna, and radial deviation. The proximal and distal joints of the radius can perform pronation and supination together. Mainly, dorsal extension is dominated by intercarpal joints.

1, wrist flexion 0 ° -80 °

Posture: Seated Axis: Radial Styloid Fixed Arm: Radial Parallel

2.Wrist joint back extension 0 ° -80 °

Posture: Seated Axis: Radial Styloid Process Fixed Arm: Radial

3.Wrist joint ulnar deviation 0 ° -30 °

Position: Seated Axis: Back of the third metacarpal root Fixed arm: Midline of forearm

4.Wrist joint radial deviation 0 ° -20 °

(Four) hand joints

1) Anatomy: Bone composition 8 wrist bones, 5 metacarpal bones, 14 phalanx bones (2 thumb bones) and several sesamoid bones.

A. Intercarpal joints: Intercarpal joints (between adjacent carpal bones) have little movement. The transverse wrist joint (between the two rows of carpal bones) has large movements.

B. Carpal metatarsal thumb thumb carpal joint abduction, large finger movements, the rest small, 4, 5 flexion, extension 15`20`

C. 3 metacarpal joints (2-5)

D. Metacarpophalangeal joint flexion, extension, lateral movement, passive rotation.

E. Flexion and extension of the interphalangeal joints.

2) Overview of Kinematics

Thumb: flexion, extension, adduction, abduction, rotation of the palm and wrist joints. 2--5 Metacarpophalangeal joint flexion, extension, abduction, adduction.

3) Function of the hand

3 functional axes; vertical axis, front-rear axis, horizontal axis

Hand movements; grip, pinch, hook.

Rest position and function position of the hand; rest position of the wrist joint flexed 10 to 15 degrees, and the rest of the finger joints naturally flexed slightly

Functional position of the hand; dorsal extension of the wrist 20 to 25 degrees, abduction of the palm side of the thumb.

4) Measurement of range of activity;

Finger ROM

1. Metacarpophalangeal joint (MP) flexion 0 ° -90 °

Position: Sitting Position Axis: Top of Metacarpophalangeal Joint Fixed Arm: Metacarpal

2. Metacarpophalangeal joint (MP) overextension 0 ° -15 ° --45 °

Position: Sitting Position Axis: Top of Metacarpophalangeal Joint Fixed Arm: Metacarpal

3. Metacarpophalangeal joint (MP) abduction 0 ° -15 ° --45 °

Position: Sitting Position Axis: Top of Metacarpophalangeal Joint Fixed Arm: Metacarpal

4. Proximal interphalangeal joint (PIP) flexion 0 ° -110 °

Position: sitting axis: PIP top fixed arm: proximal phalanx

5, distal interphalangeal joint (DIP) flexion 0 ° -90 °

Position: sitting axis: DIP top fixed arm: distal phalanx

5) Thumb ROM

1. Thumb metacarpophalangeal (MP) flexion 0 ° -50 °

Posture: Seated Axis: Top of Thumb Metacarpophalangeal Joint Fixed Arm: Metacarpal

2. Thumb interphalangeal joint (IP) flexion 0 ° -90 °

Position: Seated Axis: Top of thumb interphalangeal joint Fixed arm: Proximal phalanx

3.Radial abduction of thumb 0 ° -50 °

Position: sitting position, palm flat desktop

Axis: root of thumb metacarpal

Fixed arm: radius

4. Thumb palm abduction 0 ° -50 °

Posture: Sitting position, flat back of hand Axis axis: Thumb metacarpal root Fixed arm: Radius

5.Thumb-pointing

Measure with ruler

Third, lower limb ROM

1.Hip joint

1) Anatomy and Kinematics

The hip joint is a spherically concave joint. Neck dry angle: 110 to 140 degrees, with an average of 127 degrees.> 140 degrees is hip varus, and <110 degrees is hip varus. When the anteversion angle is 20 degrees, the anteversion angle disappears when the femur is rotated internally, and the anteversion angle is increased during the external rotation.

Hip motion axis: frontal axis flexion and extension. Sagittal axis adduction, abduction, vertical axis.

2) ROM measurement

Measure forward flexion of 125 degrees, extension of 15 degrees, adduction of 35 degrees, abduction of 45 degrees, internal and external rotation of 45 degrees.

2. Knee joint

1) Anatomy and Kinematics

The knee joint consists of the distal femur, the proximal tibia, and the sacrum. Tibiofemoral joint, patellofemoral joint, and proximal tibiofibular joint. Knee flexion and extension exercises, with slight rotation when knee flexion

Knee joint meniscus functions: protection, filling, braking, pressure adjustment, ball action, lubrication action, spring action.

2) ROM measurement

Knee joint flexion--extend 0 ~ 130 degrees. Internal rotation is 0-30 degrees, and external rotation is 0-40 degrees.

3.Ankle and foot joints

1) Anatomy and Kinematics

Ankle joint: lower tibiofibular joint (up and down, front and back, rotation, lateral movement), distance from calf joint (dorsiflexion, plantar flexion)

Ankle ligaments: anterior, posterior ligaments, triangular ligaments (inner; anterior tibial ligament, tibiofibular ligament, posterior tibial ligament, calcaneal ligament) peroneal collateral ligament (outer; anterior talus ligament, calcaneal ligament, and talus Posterior ligament

Foot: 26 bones in total; patella 7, patella 5, and phalanges 14. Foot joints; intertarsal joint, sacroiliac joint, intertarsal joint, metatarsophalangeal joint, interphalangeal joint. Important joints; subtalar joint (talar heel joint), talar boat joint, and heel roll joint. The first two joints cause the foot to varus and eversion, and the latter two joints are called the sacroiliac transverse joint to cause the adduction and abduction of the foot.

ROM measurement

Ankle motion range: 45 degrees plantar flexion, 45 degrees back extension, 40 degrees varus, 40 degrees valgus,