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

Adequate joint range of motion (ROM) is crucial for efficient movement. It also allows the body to respond more readily to various stresses. ROM is the arc of motion available at a single joint or series of joints. It is the angle through which the joint moves from the anatomical position to the extreme limit of its motion in a particular direction. In essence, it is the extent to which a part of the body can be moved around a joint or a fixed point.

ROM is essential for functional mobility. Dysfunction of the neural or musculoskeletal systems may lead to joint hypomobility or hypermobility. Range of motion assessments help us to identify if there are limitations of the bony structure or connective tissues, such as tendons, ligaments and the joint capsule, that surround the joint. It, therefore, 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 the patient performs this motion provides the clinician with information about willingness to move, ability to follow instructions, attention span, coordination, and muscle strength. It can also identify movements that cause pain and the ability to perform functional activities.

Characteristics of active range of motion:

• Performed independently by the patient
• Patient can voluntarily contract, control, and coordinate a movement. Example: AROM to flex the elbow requires the biceps to contract while the triceps relaxes
• 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 is
• Whether movement increases the 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 can produce during a voluntary muscle contraction when an external force is applied manually, mechanically, or by gravity assistance.

Characteristics of active-assisted range of motion:

• Typically performed when a 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: a patient uses their left arm to assist them in bending their right arm.

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 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 a contracting muscle.

Observations During Passive Movement

• When and where the onset of pain is
• 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. Individual factors influence the ROM achieved by each patient. The generally accepted values for the ROM for individual joints are listed 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

The impact of age on ROM has been explored extensively. For instance, infants aged between 0 and 2 years tend to have more hip flexion, hip abduction, hip external rotation, ankle dorsiflexion and elbow motion than adolescents and adults. However, they also have limitations in hip extension, knee extension and plantarflexion. This is linked to the effects of positioning in utero and is typically only modified with growth.

Older age is significantly associated with lower ROM. Older adults have reduced shoulder external rotation and horizontal flexion, passive elbow flexion, pronation and supination, wrist flexion and extension compared to younger adults. These changes may affect men and women differently. AROM in the neck, thoracic and lumbar spine decreases every decade; the greatest changes occur in thoracolumbar mobility, with up to 8 degrees reduction in range 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. These differences are more prevalent in adolescents and adults. There is, however, typically no difference in ROM between male and female infants up to the age of 2 years. In general, females have significantly increased ROM in the upper limb joints, including shoulder flexion, internal rotation and horizontal flexion, elbow flexion and extension, and wrist extension ROM. In the lower limb, females present with greater hip flexion, adduction, and internal rotation ROM than males. However, males have higher hip extension and external rotation, trunk flexion and rotation ROM.

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. Conversely, 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 - i.e. fat tissue getting caught between the bones that make up the joint.

Individuals who are an average weight have significantly higher active hip flexion, extension, and abduction range of motion when compared with individuals who are overweight and obese. Higher BMI was positively associated with reduced trunk flexion and rotation, hip extension, external rotation, and ankle joint ROM. Eichinger et al. evaluated range of motion in individuals undergoing anatomic and reverse total shoulder arthroplasty. They found that BMI was negatively correlated with the amount of shoulder internal rotation. They also found that a higher BMI affected a patient's ability to perform activities of daily living that required shoulder internal rotation.

Dominant versus Non-Dominant Side

Moromizato et al. found that there are significant ROM differences between the dominant and non-dominant sides. They note that individuals have increased shoulder internal rotation, hip abduction, and ankle plantarflexion ROM on the non-dominant side and increased shoulder external rotation, wrist flexion, and hip adduction ROM on the dominant side. This suggests that daily activities can lead to some variation in ROM.

Test Position

The testing 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. PROM and AROM are both influenced if a one-joint muscle is shortened.

Two joint and multi-joint muscles cross and influence multiple joints. A two- or multi-joint muscle is usually not long enough to allow full ROM simultaneously at all the joints that it crosses. This is called passive insufficiency. It is always important to consider passive insufficiency when measuring ROM.

Test Procedures

There is limited agreement on the number of repetitions or warm-up protocols to use before a 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 a 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, number of repeated measures and type of motion measured.

Contraindications

ROM assessment techniques are typically contraindicated when muscle contraction or motion of that 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 a tendon / ligament
  • infectious or acute inflammatory process
  • myositis ossificans or ectopic ossification
• Post-surgery:
  • the 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. The validity and reliability of ROM testing is influenced by the instrument type, 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. Please note that 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 it has been found to have 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 and 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:
  • Reliability in non-expert examiners improved with clear instructions on goniometric alignment
  • Reliability and accuracy improved when the same therapist performs all measures
• There is mixed evidence on the number of measures or whether an average of repeated measures improves assessment.
• Greater reliability is obtained when the clinician uses a standardised method with the same measurement tool and at the same time of day.
• Sources of error when using goniometry can come from the following:
  • The healthcare professional's expectations of 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

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 the 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 available here.

Assessing End-Feel

End-feel is the quality of tissue resistance to motion at the end of PROM. During a PROM assessment, end-feel is the barrier to movement that the clinician feels when slight over-pressure is applied at the end of the joint motion that prevents further movement. This assessment takes practice and sensitivity to develop the ability to determine the character of the end-feel.

Each joint has a unique structure that determines its PROM. 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. End-feel is considered abnormal when structures other than normal anatomy stop joint movement - the PROM in these joints may be normal or altered.

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. The quality of resistance is soft, and this gradually increases as the 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 is firm, although not as firm as with a capsular end-feel, and somewhat springy. Feels like stretching a tyre inner tube	Hip Flexion with Knee Straight (SLR): Passive elastic tension of the hamstring muscles
	Ligamentous End Feel Occurs when tension in the 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 and 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 a 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 the ulna and the olecranon fossa of the humerus

Table.2 Abnormal End-feel

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 the 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 to distinguish among the various normal (physiological) and abnormal (pathological) end-feels. It also 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 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.
   • A 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
   • A non-capsular pattern restriction in joint motion in any pattern other than a capsular one. It may indicate the presence of a derangement, a restriction of one part of the joint capsule, or an extra-articular lesion, that obstructs joint motion.
   • A 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 Assessment

There are some overall guiding principles when assessing ROM. Typically, when conducting a ROM assessment, we compare the affected side to the unaffected side. Where possible, we assess the AROM of the unaffected limb first. This allows the examiner to establish the patient's willingness to move and get a baseline for normal movement of the joint being tested. It also shows the patient what to expect, increasing their 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 there are any 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 explain the ROM assessment and measurement procedure to the patient. Explain and demonstrate the examiner’s and the patient's role and confirm the patient'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. The joint being assessed should be in the anatomical position and be able to move through its full available range without being obstructed. If the movement being assessed causes a two- or multi-joint muscle to lengthen or stretch, ensure that the non-test joint/s crossed by this muscle are positioned so that the muscle is in a shortened position. This will prevent passive insufficiency from restricting joint ROM. If there are any differences in terms of the patient's starting position, make sure you record this in your documentation. For example, if a patient's 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 as much as possible. Ensure the proximal joint is stabilised to minimise any substitute movements and then passively move the other end to lengthen the muscle. Substitute movements at other joints may occur without adequate stabilisation, which will affect results. To increase accuracy, therapists should know and recognise 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 end-feel, and return the limb to the start position. Determine the presence of a capsular or non-capsular pattern of movement.
• Aligning the Measurement Tool: 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. Typically bony landmarks are used to align 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.

• Documentation: Typically, ROM numerical or pictorial charts are used to record the available ROM, with the 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 helps us:

• determine what structures or tissues may be impacting movement
• quantify baseline limitations of motion
• support clinical decision-making regarding the management and selection of specific therapeutic interventions
• support outcome analysis after a particular intervention has been applied
• 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 practise the techniques on as many people 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 that the muscle is in a shortened position at the joint/s not being tested.
• 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.