Joint Stability and Range of Motion Assessment

Joint Stability and Congruence

Stability and Congruence in Articular Joints:

• Passive Factors: Joint capsule, ligaments.
• Active Factors: Muscular system (monoarticular and biarticular muscles).

Normal Mobility

Spatial Position: Within physiological ranges.

• Active Motion: Performed by active contraction of the musculature itself.
• Functional Motion: Lower-level movements.

Physiological Limitations

• Biomechanical
• Pathological
• Systemic

These limitations result in an active, functional state of the patient.

Passive Mobility

Performed by the examiner.

Anatomical Limitations

• Articular Top
• Pathological Pain

The score depends on the type of patient and the structural state.

Goniometry

Goniometry is the measurement of joint ranges of motion, whether normal or pathological. It is based on the angles between body segments, using an instrument called a universal goniometer. The anatomical position should be considered as 0°, with points cephalad to the subject, while 180° corresponds to points caudad. The neutral position defines the starting position of measurement and coincides with the anatomical position. If the segment moves away from the anatomical position, the 0° axis is defined proximally, and the 180° axis is defined distally.

Osteokinematics

Osteokinematics refers to the movement of the bony epiphysis in relation to joint movement. Bony movements are described as rotary movements occurring around an axis of rotation. The processes measured by goniometry describe the rotary movement of the epiphysis.

Arthrokinematics

Arthrokinematics refers to the movement of articular surfaces.

Range of Motion (ROM)

Range of motion describes the extent of movement of one or more joints.

Hypomobility and Hypermobility

• Hypomobility: A decrease in the amplitude of movement below standard values according to age, sex, and joint type.
• Hypermobility: An increase in the amplitude of movement exceeding normal values.

Technique for Measuring Range of Motion

1. Locate the patient in the initial position.
2. Palpate and mark reference bone structures: fixed axis, rotation axis, and mobile axis.
3. Establish the measuring position.
4. Request the patient to actively move or perform passive mobilization of the segment.
5. Place the goniometer in the final position and measure.

Specific Joint Ranges of Motion

Shoulder

• Flexion (160-180°), Extension (40-60°)
  • E/R: 0-1 cm under the acromion (greater tubercle)
  • E/F: Mid-axillary line
  • E/M: Line from the greater tubercle to the lateral epicondyle
• Abduction (160-180°)
  • E/R: Anterior aspect of the humeral head
  • E/F: Line parallel to the sternum
  • E/M: Mid-anterior line of the humerus
• Rotation (80-90°)
  • E/R: Olecranon
  • E/F: Gravity
  • E/M: Line from the olecranon to the ulnar styloid

Elbow

• Flexion (135-145°), Extension (0-45°)
  • E/R: Lateral epicondyle
  • E/F: Mid-lateral line of the humerus
  • E/M: Line to the radial styloid
• Supination (80-90°)
  • E/R: Medial ulnar styloid
  • E/F: Line parallel to the humerus
  • E/M: Line parallel to the radial styloid
• Pronation (80-85°)
  • E/R: Lateral epicondyle
  • E/F: Mid-lateral line of the humerus
  • E/M: Line to the radial styloid

Wrist

• Flexion (75-90°), Extension (75-80°)
  • E/R: Mid-interarticular line of the wrist
  • E/F: Mid-lateral line of the ulna
  • E/M: Line to the head of the 5th metacarpal

Muscle Evaluation

Head Extension

M1: Splenius capitis and synergists (rectus capitis posterior major, obliquus capitis superior, and longissimus capitis). Perform a rotating movement with a single contraction.

• M5: 10 repetitions
• M4: Less than 10 repetitions
• M3: Resists slight resistance and repeats
• M2: Lying laterally without resistance, performs the movement
• M1: Contraction of the muscle is detected only by palpating the occipital region

Neck Extension on Trunk

M1: Splenius cervicis, synergists (transverse cervical, iliocostal cervical). The patient lies prone on a stretcher with the head out and performs an extension movement against resistance.