Assessing Range of Motion

Original Editors - Naomi O'Reilly and Tarina Van Der Stockt

Top Contributors - Naomi O'Reilly, Jess Bell, Ewa Jaraczewska and Tarina van der Stockt      

Introduction

Efficient movement with minimal effort relies on adequate joint range of motion (ROM), which allows the joint to adapt more readily to stresses imposed on the body. ROM is the arc of motion available at a single joint or series of joints. It is the angle through which joint moves from the anatomical position to the extreme limit of its motion in a particular direction. Effectively, it is the extent to which a part of the body can be moved around a joint or a fixed point.

ROM is an essential part of human movement for the individual body’s functional mobility. Dysfunction of the neural or musculoskeletal systems may lead to hypomobility or hypermobility. Assessment of ROM allows us to identify any limitation of the bony structure or connective tissues such as tendons, ligaments and joint capsule that surround the joint and forms an integral part of patient assessment. 

Types of Range of Motion

Active Range of Motion

Active range of motion (AROM) is the range of movement that can be achieved when opposing muscles contract and relax, resulting in joint movement. It is the arc of motion a patient produces during a voluntary, unassisted muscle contraction. The way this motion is performed provides the clinician with information about levels of consciousness, willingness to move, ability to follow instructions, attention span, coordination, and muscle strength. It can also define movements that cause pain and the ability to perform functional activities.

Characteristics of the active range of motion:

• Performed by the patient independently.
• Patient can voluntarily contract, control, and coordinate a movement. Example: AROM to flex the elbow requires the biceps to contract while the triceps relax.
• AROM is typically less than PROM as each joint has a small amount of available motion that is not under voluntary control.

Observations During Active Range of Motion

• Willingness of the patient to move
• When and where the onset of pain
• Whether movement increases intensity and quality of pain
• Reaction of the patient to pain
• Amount of observable restriction and its nature
• Pattern of movement
• Rhythm and quality of movement
• Movement of associated joints

Active-assisted Range of Motion

Active-assisted range of motion (AAROM) is the range of movement that can be achieved when the joint receives partial assistance from an outside force. It is the arc of motion a patient produces during a voluntary muscle contraction to the extent they can when an external force is applied manually, mechanically, or by gravity assistance.

Characteristics of the active-assisted range of motion:

• Typically performed when the patient needs assistance with a movement from an external force because of weakness, pain, or changes in muscle tone.
• The muscle considered the primary mover needs assistance to complete the movement. Example: the patient using their left arm to assist them in lifting their right arm to bend the elbow.

Passive Range of Motion

Passive range of motion (PROM) is the range of movement achieved when an outside force exclusively causes joint movement. It is the arc of motion produced by the therapist without assistance from the patient. PROM provides information about the integrity of the joint surfaces, extensibility of the joint capsule and surrounding ligaments, muscle, fascia and skin.

Characteristics of the passive range of motion:

• Typically performed when a patient is unable or not permitted to move the body part actively.
• Movement is produced during muscular inactivity or when muscular activity is maximally reduced.
• PROM is typically greater than AROM due to the stretch of the tissues surrounding the joint and the reduced bulk of relaxed muscles compared to contracting muscle and is used during the assessment.

Observations During Passive Movement

• When and where the onset of pain
• Whether movement increases the intensity and quality of pain
• Pattern of Restriction
• End-feel
• Movement of associated joints

Each joint has a typical or normative range of values for ROM, while each person has a different amount of ability to achieve it. You can find out the generally accepted values for a ROM for individual joints here.

Factors Impacting Range of Motion

ROM varies among individuals and can be influenced by various factors, including age, gender, physical constitution such as body mass index, occupational and recreational activities, and test procedures.

Age

Significant research has explored the impact of age on ROM, with gender typically having no impact in newborns up to the age of 2 years old, who tend to have more hip flexion, hip abduction, hip external rotation, ankle dorsiflexion and elbow motion in comparison to adolescents and adults. At the same time, they show limitations in hip extension, knee extension and plantarflexion linked to the effects of positioning in utero, which typically is only modified with growth. Older age is significantly associated with lower ROMs than younger adults in shoulder external rotation and horizontal flexion, passive elbow flexion, pronation and supination, wrist flexion and extension. These changes may affect men and women differently. Increasing loss of AROM in the neck, thoracic and lumbar spine occurs every decade, with the greatest change seen in thoracolumbar mobility with up to an 8 degrees reduction each decade.

Gender

The effects of gender on ROM appear to be joint and motion specific. Females are reported to have greater ROM than males, with these differences more prevalent in adolescents and adults. Females show significantly increased ROM in the upper limb joints. It affects their shoulder flexion, internal rotation and horizontal flexion, elbow flexion and extension, and wrist extension. In the lower limb, females present with greater than males hip flexion, adduction, and internal rotation. However, males have higher ROM for hip extension and external rotation, trunk flexion and rotation.

Weight

Higher lean body mass is related to reduced ROM in shoulder external rotation and horizontal extension but increased ROM for wrist flexion and hip adduction. While increased body fat percentage has been associated with decreased shoulder external rotation, shoulder horizontal flexion, and elbow flexion and extension. Negative correlations between body fat percentage and several joint motions may result from physical obstruction by fat tissue caught between the bones.

Normal-weight individuals have significantly higher active hip flexion, extension, and abduction range of motion when compared with overweight and obese individuals. Higher BMI was positively associated with trunk flexion and rotation, hip extension, external rotation, and ankle joint movements. Eichinger et al. found that BMI was negatively correlated with the degree of shoulder internal rotation using a standard clinical evaluation of vertebral level in patients undergoing anatomic and reverse total shoulder arthroplasty. Higher BMI also affected the patient's ability to perform shoulder internal rotation-related ADLs.

Dominant versus Non-Dominant Side

ROM differences between the dominant and non-dominant sides were significant, with increased ROM in shoulder internal rotation, hip abduction, and ankle plantarflexion on the non-dominant side. An increased shoulder external rotation, wrist flexion, and hip adduction were observed on the dominant side, which suggests that daily activities can lead to some variation in ROM.

Test Position

The resting position of a joint can greatly influence the ROM available due to the muscle length of the opposing muscle. One joint muscles cross one joint and thus only influence the motion in that joint. The PROM and AROM will be influenced if one joint muscle is shortened.

Two joint and multi-joint muscles cross and influence multiple joints, and the muscle's length is usually insufficient to allow full PROM simultaneously at all the joints that the muscle crosses. This is called passive insufficiency, which effectively occurs when the length of a muscle prevents the full ROM at the joint or joints that the muscle crosses over. It is always important to consider passive insufficiency when measuring ROM.

Test Procedures

Research has limited agreement on the number of repetitions or warm-up protocols to use before ROM assessment. Evidence on stretching has shown increased mobility, stretch tolerance and reduced passive torque during acute stretch training after only a few repetitions of a stretch. This phenomenon occurs during ROM assessment. Therefore, differences in the measurement protocol concerning the measured repetitions and warm-up exercises can lead to different measurement results of up to 6 degrees. To counteract the impact of testing procedures on ROM, healthcare professionals must use a consistent protocol for warm-up, type of instrument, the number of repeated measures and type of motion measured.

Contraindications

ROM assessment techniques are typically contraindicated where muscle contraction or motion of the part of the body could disrupt the healing process or result in injury or deterioration of the condition. Some examples of conditions where ROM may be contraindicated include the following:

• Suspected or Confirmed
  • Joint Subluxation / Dislocation
  • Unhealed or Unstable Fracture
  • Rupture of Tendon / Ligament
  • Infectious or Acute Inflammatory Process
  • Myositis Ossificans or Ectopic Ossification
• Post Surgery
  • Tissue healing process can be disrupted
• Osteoporosis or Bone Fragility
  • Forced measurements may cause iatrogenic injury  

Precautions

Conditions where measurement of ROM may be appropriate, with added precautions if movement might aggravate the condition include;

• Presence of Pain
• Infection or Inflammation around a Joint
• Hypermobility
• Instability
• Haemophilia
• Bony Ankylosis
• After Prolonged Immobilisation

Assessing and Measuring Range of Motion

There are different instruments used to measure ROM. The choice of instrument depends on the movement to be measured, the size of the limb, the instrument’s accuracy, availability, cost, ease of use, and validity and reliability. ROM's Validity and reliability is influenced by instrument types, differences among joint actions and body regions, passive versus active measurements, intra-tester versus inter-tester measurements, and different patient types.

Visual Estimation

Visual estimation provides subjective information compared to objective goniometric measurements, so it is not recommended. However, visual estimates made before goniometric measurements may help to reduce errors attributable to incorrect readings of the goniometer, but knowledge of the estimate has also been shown to influence goniometric measurement results.

Goniometry

A goniometer is the most common instrument used to measure ROM. The term 'goniometry' refers to the measurement of angles, which in rehabilitation settings is the measurement of angles in each plane at the body's joints. There are limited validity studies on goniometry, but they have found high criterion validity in measurements of knee joint angles when compared to x-ray joint angles. Reliability depends on the joint and motion being assessed, but generally, the universal goniometer has been shown to have good to excellent reliability. It is more reliable than visual estimation, especially with inexperienced examiners.

The following are key principles of goniometry:

• Research shows high intra- and inter-rater reliability of the universal goniometer, with reliability in non-expert examiners, improved with clear instructions on goniometric alignment.
• The same therapist should perform all measures to improve accuracy whenever possible.
• Evidence is mixed on the number of measures to take or whether an average of repeated measures improves assessment.
• Sources of error when using goniometry can come from the following:
  • Healthcare professional's expectations of what is considered the ROM
  • Reading the wrong side of the scale on the goniometer
  • Change in the patient’s motivation to perform or take successive measurements at different times of the day.
  • Greater reliability is obtained when the clinician uses a standardised method with the same measurement tool and at the same time of day.

Goniometric measurement has the following characteristics:

• Versatility: Measures joint position and ROM at almost all joints of the body
• Construction: Typically plastic or metal, contains a body (similar to a protractor) and two lever arms (stationary and movable)
• Alignment: Arms align with proximal and distal segments of the individual’s joints
• Cost: Varies from $5 to $100

You can read more about other goniometry tools, including inclinometers and smartphone apps now available here.

Assessing the End-Feel

End-feel is the quality of tissue resistance to motion at the end of PROM. Each joint has a unique structure that determines the amount of PROM available to that specific joint. In some joints, the joint capsule limits the amount of movement in certain directions, while in other joints, the ligaments or bones limit the movement because of the joint structure. A normal end-feel exists when the joint has full PROM. An abnormal end-feel exists when there is either an altered PROM or a normal PROM, but structures other than normal anatomy stop joint movement.

When the therapist performs the PROM, the end-feel is the barrier the therapist feels when slight over-pressure is applied at the end of the joint motion that prevents further movement, which takes practice and sensitivity to develop the ability to determine the character of the end-feel.

Table.1 Normal End-feel

End-feel	Description	Example
Soft	Soft Tissue Approximation Occurs when two soft tissue masses meet one another, limiting further movement. Quality of resistance is soft, with a gradual increase as soft tissue is compressed between body parts	Knee Flexion; Contact between the soft tissue of the posterior leg and posterior thigh
Firm	Muscular End Feel Occurs when muscular tension limits the ROM. Quality of resistance felt is firm, although not as firm as with capsular end-feel, and somewhat springy. Feels like stretching a tyre inner tube	Hip Flexion with Knee Straight (SLR); Passive elastic tension of Hamstring Muscles
	Ligamentous End Feel Occurs when tension in ligaments surrounding the joint limits the ROM. Quality of resistance felt is firm, although not as firm as with capsular end-feel, and somewhat springy. Feels like stretching a leather belt.	Forearm Supination; Tension in the Palmar Radioulnar Ligament of the Inferior Radioulnar Joint, Interosseous Membrane, Oblique Cord
	Capsular End Feel Occurs when the joint capsule and surrounding non-contractile tissues limit the ROM. Quality of resistance felt is firm but not hard. There is a slight "give" to the movement. Feels like stretching a leather belt, with more resistance than ligament.	Extension of Metacarpophalangeal Joints Tension in the Anterior Capsule
Hard	Bone on Bone Occurs when the approximation of two bones stops the ROM. Quality of the resistance felt is very hard and abrupt, with further motion impossible.	Elbow Extension; Contact between the Olecranon Process of Ulna and the Olecranon Fossa of Humerus

Table.2 Abnormal End-feels

End-feel	Description	Example
Empty	No real end-feel with no mechanical limitation to the end of the range Pain typically prevents the body part from moving through available ROM No resistance is felt	Fracture Abscess Bursitis Acute Joint Inflammation Psychogenic Disorder
Soft	Occurs sooner or later in the ROM than is usual or in a joint that normally has a firm or hard end feel. Feels boggy (mushy with a soft quality to it )	Soft Tissue Oedema Synovitis
Firm	Occurs sooner or later in the ROM than is usual or in a joint that normally has a soft or hard end feel.	Increased Muscle Tone Connective Tissue Shortening, e.g. capsular, muscle, ligament and fascia
Hard	Occurs sooner or later in the ROM than is usual or in a joint that normally has a soft or firm end feel. A bony grating or bony block is felt.	Fracture Osteoarthritis Chondromalacia Myositis Ossificans Loose Bodies in Joint
Springy	A rebound is seen or felt during movement	Internal Derangement Torn Meniscus
Spasm	Involuntary muscle contraction that prevents normal ROM Often accompanied by pain - more indicative of an acute or severe lesion Where no pain is present, it may be an increase in muscle tone secondary to Central Nervous System involvement	Acute Protective Spasm Acute Arthritis Fracture Lesion of the Central Nervous System
Loose	Movement beyond expected anatomical limits	Extreme Hypermobility Ankle Instability Shoulder Instability

Determination of the end-feel must be carried out slowly to enable detection of the end of the ROM and distinguish among the various normal (physiological) and abnormal (pathological) end-feels and requires repeated practice.

Assessing the Pattern of Limitation or Restriction

In addition to evaluating end-feel, the examiner must look at the pattern of limitation or restriction. Where there is a limitation or restriction in ROM, it will be important to assess the restriction pattern to determine whether there is a capsular or non-capsular loss pattern.

1. Capsular Pattern
   • If there is a lesion of the joint capsule or a total joint reaction is present, a characteristic pattern of restriction in PROM will occur: Restriction is a limitation of pain and movement in a joint-specific ratio, which is usually present with arthritis, or following prolonged immobilisation.
   • Capsular pattern manifests as a proportional limitation of joint motions characteristic to each joint; for example, the capsular pattern of the elbow joint differs from the pattern of restriction at the ankle joint.
   • Only joints controlled by muscles exhibit capsular patterns, while joints that rely primarily on ligaments for their stability do not exhibit capsular patterns.
   • Some research suggests capsular patterns may not be relied upon as much as previously thought.
2. Non-capsular Pattern
   • Restriction is a limitation in a joint in any pattern other than a capsular one and may indicate the presence of either a derangement, a restriction of one part of the joint capsule, or an extra-articular lesion, that obstructs joint motion.
   • Non-capsular pattern typically indicates the absence of a total joint reaction.

You can read more about Capsular versus Non-capsular Patterns here.

Principles of Measurement

There are some overall guiding principles when assessing ROM. Typically ROM assessment compares to the unaffected side. The unaffected limb AROM is assessed first where possible, which allows the examiner to establish the patient's willingness to move and get a baseline for normal movement for the joint being tested. This also shows the patient what to expect, increasing patient confidence and reducing apprehension when the affected side is tested. Any painful movements should be completed last, minimising the risk of overflowing painful symptoms.

Preparation: Determine whether contraindications or precautions and what joints and motions must be tested. Organise the testing sequence by body position to minimise changes in positioning.

Communication: Briefly explains the ROM assessment and measurement procedure to the patient. Explain and demonstrate the examiner’s and individual’s roles and confirm the individual’s understanding and willingness to participate.

Expose the Area: Explain and demonstrate anatomical landmarks and why they must be exposed. Adequately expose the area and drape the patient as required.

Positioning: Ensure the patient is comfortable and well supported with the joint to be assessed in the anatomical position allowing for complete and unobstructed joint movement during the assessment. If movement being assessed will lengthen or stretch a two- or multi-joint muscle, ensure to move the non-test joint crossed by the muscle into position so that the two-joint or multi-joint muscle is placed on slack to prevent passive insufficiency restricting joint ROM. If there is any variance to the patient's position, ensure to make a note of this in your documentation; for example, if the elbow is unable to achieve full extension, record the starting angle before measuring the range of motion of flexion.

Stabilisation: Isolate the motion to one joint to ensure a true measurement of the motion. Ensure the proximal joint is stabilised to minimise any substitute movements and passively move the other end to lengthen the muscle. Substitute movements at other joints may occur without adequate stabilisation, affecting results. To increase accuracy, therapists should know and recognise the possible substitute movements at each joint they are assessing.

Assess End Feel and Pattern of Restriction: Move the distal joint segment to the end of the PROM and apply gentle overpressure to determine end-feel. Visually estimate the passive range of motion, note the pain's end feel and presence, and return the limb to the start position. Determine the presence of a capsular or non-capsular pattern of movement.

Aligning Measurement Tool: Bony landmarks usually align our measurement tools. You will usually need to find three landmarks to align a goniometer:

1. Fulcrum or Axis - Positioned over a point near the joint's axis of rotation.
2. Stationary Arm - Usually aligned with the midline of the stationary segment of the joint.
3. Moving Arm - Usually aligned with the midline of the moving segment of the joint.

The goniometer is first aligned to measure the defined zero position for the ROM. If it is impossible to attain the zero or anatomical position, the joint is positioned as close as possible to the zero position, and the starting angle is measured.

Documentation: Typically, ROM numerical or pictorial charts are used to record the available ROM, with starting and final position recorded; for example, Elbow Flexion 0 - 150 degrees. When it is impossible to begin the movement from the 0-degree start position, the range of motion is recorded by writing the number of degrees the joint is away from the 0° at the beginning of ROM; For example, Elbow Flexion 10-150 degrees.

Clinical Significance

On completion of the ROM assessment, the therapist must consider the impact of the deficit on the patient’s daily life. Assessing ROM help us to determine what structures or tissues may be impacting movement and help to quantify baseline limitations of motion, support clinical decision-making regarding the management and selection of specific therapeutic interventions, outcome analysis after a particular intervention has been applied, and compare the efficacies of different interventions.

Summary

Having adequate joint ROM enables optimal movement. Thus, assessing ROM is an important piece of the clinical puzzle. Proficiency in assessing and measuring ROM is gained through practice. It is important to practice the techniques on as many persons as possible to become familiar with variations between individuals.

When performing your assessment, please remember the following:

• The testing position of a joint can greatly influence the ROM available due to the muscle length of opposing muscles.
• If the movement being assessed will lengthen or stretch a two- or multi-joint muscle, ensure to move the non-test joint crossed by the muscle into a position so that the two-joint or multi-joint muscle is placed on slack.
• When we observe changes in ROM, we must always consider our findings in the context of the rest of our assessment, including posture, muscle length, muscle strength, tone, neural tests, movement analysis and more, and apply our clinical reasoning skills to what we find.

References