Peripheral Joint Mobilization II BASIC CONCEPTS OF JOINT

Peripheral Joint Mobilization

II. BASIC CONCEPTS OF JOINT MOTION A. Joint Shapes : The type of motion occurring between bony partners within a joint is influ enced by the shapes of the joint surfaces. The shapes may be described as ovoid or sellar"'.

. 1. Ovoid One surface is convex; the other is concave 2. Seilar (Saddle) One surface is concave in one direction and convex in the other, with the opposing surface convex and concave, respectively; similar to a horse back rider being in complementary opposition to the shape of a saddle A

Types of Motion As a bony lever moves about an axis of motion, there is also movement of the bone surface on the opposing bone surface within the join. 1. The movement of the bony lever is called swing and is classically de scribed as flexion, extension, abduction, adduction, and rotation. The amount of movement can be measured in degrees with a goniometer and is called range of motion. . 2 Motion of the bone surfaces within the joint is a variable combination of rolling, sliding , or spinning. These accessory motions allow for greater angulation of the bone as it swings. For the rolling, sliding, or spinning to occur, there must be adequate capsule laxity or joint play.

Roll Characteristics of one bone rolling on another (1)The surfaces are incongruent. (2)New points on one surface meet new points on the opposing surface (3)Rolling results in angular motion of the bone. (4)Rolling is always in the same direction as the angulating bone mo tion whether the surface is convex or concave.

(5) Rolling, if it occurs alone, causes compression of the surfaces on the side to which the bone is angulating and separation on the other side. Passive stretching using bone angulation alone may cause stressful compressive forces to portions of the joint surface, potentially leading to joint damage. (6) In normal functioning joints, pure rolling does not occur alone but in combination with joint sliding and spinning. Some muscles may function to cause the slide with normal active motion. b.

Slide ' Characteristics of one bone sliding across another (1) For a pure slide, the surfaces must be congruent, either flat (Figure 4 A) or curved (Figure 4 B). (2) The same point on one surface comes into contact with new points on the opposing surface. (3) Pure sliding does not occur in joints, since the surfaces are not completely congruent.

(4 The direction in which sliding occurs depends on whether the mov ing surface is concave or convex. Sliding is in the opposite direction of the angular movement of the bone if the moving joint surface is convex. Sliding is in the same direction as the angular movement of the bone if the moving surface is concave

c. Combined roll-sliding in a joint 3 (1)The more congruent the joint surfaces are, the more sliding there is of one bony partner on the other with movement. (2)The more incongruent the joint surfaces are, the more rolling there is of one bony partner on the other with movement. (3)For joint mobilization techniques, the sliding component of joint motion is used to restore joint play and reverse joint hypomobility. Roll ing is not used since it causes joint compression. When therapist passively moves the articulating surface in the direction in which the slide normally occurs, the technique is called translatoric glide , or glide 8. It is used to control pain when applied gently or to stretch the capsule when applied with a stretch force.

d) Spinning (1) There is rotation of a segment about a stationary mechanical axis (2)The same point on the moving surface creates an arc of a circle as the bone spins (3)Spinning rarely occurs alone in joints but in combination with rolling and sliding .

4) Three examples of where spin occurs in joints of the body are the shoulder with flexion/extension, the hip with flexion/extension, and the radiohumeral joint with pronation/supination. .

Compression is the decrease in the joint space between bony partners. a. Compression occurs in the lower extremity and spinal joints when weight bearing. B. Some compression occurs as muscles contract; this provides to the joints. c. As one bone rolls on the other, some compression also occurs on the side to which the bone is angulating. d. Normal intermittent compressive loads help move synovial fluid thus help maintain cartilage health. e. Abnormally high compression loads may lead to articular changes and deterioration 6.

. Traction is the distraction or separation of the joint surfaces. For distraction" to occur within the joint, the surfaces must be) apart. The movement is not always the same as pulling on the long axis of one of the bony partners. For example, if traction is applied to shaft of the humerus, it will result in a glide of the joint surface. Distraction of the glenohumeral joint requires a pull at right angle to the glenoid fossa ). c. whenever there is pulling on the long axis of a bone, the phrase long-axis traction will be used. Whenever the surfaces are I pulled apart at right angles, the terms distraction, joint traction, or separation will be used. .

For joint mobilization techniques, distraction is used to relieve' pain when applied gently or to stretch the capsule when applied with a stretch force. Arc Stretching Versus Joint Glide Stretching. 1 Passive range of motion exercises, or arc stretching procedures, when the bony lever is used to stretch a tight joint capsule, may cause increased pain or joint trauma because : a. the use of a lever significantly magnifies the force at the joint. b. the force causes excessive joint compression in the direction of the rolling bone c. the roll without a slide does not replicate normal joint mechanics.

2. Joint mobilization stretching procedures, when the translatoric slide component of the bones is used to stretch a tight capsule, are safer and more selective because a. the force is applied close to the joint surface and controlled at an inten sity compatible with the ology. b. the direction of the force replicates the joint mechanics. c. the amplitude of the motion is small yet specific to the restricted portion of the capsule or ligaments, thus the forces are selectively applied to the desired tissue.

PROCEDURES FOR APPLYING JOINT MOBILIZATION TECHNIQUES A. Evaluation and Assessment If the patient has limited or painful motion evaluate and assess what tissues are limiting. Determine whether treatment will be directed primarily toward relieving pain or or soft tissue limitation. 1'. The quality of pain helps determine the stage of recovery and the dosage of techniques If pain is experienced before tissue limitation—such as the pain that occurs with muscle guarding following an acute injury or during the active stage of a disease—pain inhibiting joint techniques may be used to relieve pain. The same techniques will also help maintain joint play. (Stretching under these circumstances is contraindicated.

b. If pain is experienced concurrently with tissue limitation—such as the pain and limitation that occur when damaged tissue begins to heal the limitation is treated cautiously. Gentle stretching techniques spe cific to the tight structure are used in order to gradually improve ment yet not exacerbate the pain by reinjuring the tissue. c. If pain is experienced after tissue limitation is met because of stretching of tight capsular or periarticular tissue, the stiff joint can be aggres sively stretched with joint play techniques and the periarticular tissue with the stretching techniques.

2. The joint capsule is limiting motion and should respond to mobilization techniques if the following signs are present: • The passive range of motion for that joint is limited in a capsular pattern. • There is a firm capsular end feel when overpressure is applied to the tissues limiting the range • There is decreased joint play movement when mobility tests (articula tions) are done.

G. Direction of Movement 1. The direction of movement during treatment is either parallel to or perpendicular to the treatment plane. TREATMENT PLANE is described as a plane perpendicular to a line running from the axis of rotation to the middle of the concave articular surface. The plane is in concave partner so its position is determined by the position of the concave bone

. 2 Joint traction techniques are applied perpendicular to the treatment plane. The entire bone is moved so that the joint surfaces are separated. 3 Gliding techniques are applied parallel to the treatment plane a. Glide in the direction in which the slide would normally occur for the desired motion. ; .

shoulder complex is made up of four joints, all of which contribute to attaining full range of motion at the shoulder: the glenohumeral joint, the sternoclavicular joint, the acromioclavicular joint, and the scapulothoracic joint. Approximately 120 degrees of motion into flexion and abduction must take place at these joints for most functional activ ities to occur. The glenohumeral. articulation is the most mobile joint in the human body

Scapulothoracic joint elevation and protraction accompany scapular elevation. Mobility at this articulation characteristically is hypermobile in patients with chronic or severe gleno humeral restrictions, resulting in alteration of the normal scapulohumeral rhythm. Scapular el evation is accompanied by a caudal glide of the clavicle on the sternum and lateral rotation of the scapula.

With abduction, the humeral head glides caudally into the lower concavity of the glenoid. The inferior folds of the joint capsule, present when the shoulder is in the anatomic position, unfold as abduction occurs. During im mobilization in adduction these folds often adhere to one another. Restoring and maintaining the normal joint accessory motion of caudal gliding of the humerus on the glenoid is thought to reduce these adhesions, allowing the humeral head to glide into the inferior cavity of the glenoid with shoulder abduction.

With shoulder abduction to 90 degrees the clavicle elevates and protracts as the scap ula elevates, protracts, and rotates laterally. 5 The clavicle elevates 4 degrees for every 10 de grees of humeral elevation. 4'8 Most of this motion takes place at the stemoclavicular joint. After reaching 90 degrees the acromioclavicular joint becomes close packed and does not con tribute to additional shoulder abduction. Additional motion into abduction occurs as the clav icle rotates dorsally on its longitudinal axis. " The coracoclavicular ligament is responsible for this motion in that it pulls the clavicle into rotation as the clavicle moves away from the co racoid process during elevation. 8

In both planes of motion, combining external rotation with abduction aids elevation by bringing the greater tuberosity behind the acromial shelf, thus avoiding impingement of the two structures in the suprahumeral space. It therefore is crucial to ensure that adequate external rotation is present before aggressively treating abduction re strictions. Abduction is restored by gliding the humerus caudally, and external rotation is re stored by gliding it ventrally.

Adduction to neutral occurs in conjunction with humeral cranial gliding and rarely is limited. Horizontal adduction occurs in conjunction with humeral dorsal gliding, and horizontal abduction with ventral gliding. Limitations in both these directions often occur in conjunction with other limitations. Flexion occurs in conjunction with internal rotation of the humerus. because musculature re sponsible for shoulder flexion also internally rotates the shoulder 2. Flexion and internal rotation are restored by gliding the humerus dorsally i Extension to neutral rarely is limited.

Hyperextension is accompanied by a ventral glide of the humerus. Scapular and clavicular motion during flexion is similar to motion during abduction, with several exceptions. Flexion is accompanied by more scapular protraction than with abduc tion 8. Scapular setting takes place during the first 60 degrees of flexion 8 '4, after which the glenohumeral to scapulothoracic motion ratio of 2: 1 ensues 8 '4. The greater tuberosity does not obstruct the suprahumeral space with flexion, as it does with abduction 8.

Scapulothoracic Caudal Glide Scapulothoracic Cranial Glide

Scapulothoracic Lateral Glide Scapulothoracic Medial Glide

Sternoclavicular Caudal Glide Sternoclavicular Cranial Glide and

Acrominoclavicular Anterior Glide Acrominoclavicular Posterior Glide

Glenohumeral Lateral Distraction Glenohumeral Caudal Glide

Glenohumeral Anterior Glide Glenohumeral Posterior Glide

The elbow joint generally is classified as a hinge joint 3. Flexion and extension occur at the humeroulnar and humeroradial joints. Pronation and supination are considered motions of the forearm and take place at the humeroradia!, proximal radioulnar, distal radioulnar, and ul nomeniscotriquetral joints. Most functional activities occur between 30 and 130 degrees of flexion, and between 50 degrees of pronation and 50 degrees of supination 6. Positional faults are not uncommon at the humeroradial joint. Proximal positional faults frequently occur after a fall on an outstretched arm. Distal positional faults often result from a pull on the patient's arm, and therefore are especially common in young children.

Medial and lateral gapping and gliding are the primary oscillation techniques used to re store extension and flexion at the humeroulnar joint. Dorsal and ventral glides, which would be the appropriate techniques for restoring these motions, are ineffective, because the ulnar articular surface encompasses such a large arc in the frontal plane that the two joint surfaces jam together when these manipulation techniques are attempted. Therefore the only approaches available to increase joint play at the humeroulnar joint are medial and lateral Flexion is accompanied by adduction or varus angulation at the elbow, and extension by abduction or valgus angulation.

Humero ulnar Distraction Humero ulnar Lateral Glide and Humero ulnar Medial Glide

Humero radial Distraction

Humero radial Anterior Glide Humero radial Posterior Glide

The wrist is made up of the radiocarpal (radioscaphoid and radiolunate) joint, the ulnocarpal (ulnomeniscotriquetral) joint, the triquetrium pisifbim articulation, and the midcarpal joint. Wrist range of motion is considered functional if 10 degrees of flexion and 35 degrees of ex tension are present, * because this amount of motion allows the wrist to position the hand for skilled activities.

WRIST FLEXION AND EXTENSION The most common belief is that wrist motion occurs primarily between the radiocarpal and ulnocarpal row and the midcarpal row. Dorsal glides of the scaphoid, lunate, and triquetrium will assist in the restoration of flexion, and volar glide of these bones will help restore extension. A greater percentage of motion for extension takes place at the radiocarpal and ulnocarpal joints, whereas relatively more motion for flexion occurs at the midcarpal joint 9 '8 '6. Radio carpal and ulnocarpal excursion therefore should be emphasized when restoring extension, and midcarpal excursion should be emphasized when restoring flexion.

WRIST RADIAL AND ULNAR DEVIATION Radial deviation occurs in conjunction with flexion, primarily of the scaphoid on the ra dius 9' 10 and to a lesser extent the other proximal row of carpal bones on the radius 7 '6. The opposite occurs with ulnar deviation. Distally the midcarpal row extends slightly during radial deviation, and flexes during ulnar deviation 3. Thus restoring joint play into flexion and exten sion, as well as individual intercarpal mobility, is important in restoring radial deviation and ulnar deviation.

Wrist Distraction Wrist Anterior Glide Wrist Posterior Glide