Week 1: Principles of Joint Motion Assessment & Principles of Muscle Testing

Sagittal Plane

Divides the body into right and left portions; motions include flexion and extension

Frontal/Coronal Plane

Divides the body into anterior and posterior portions; motions include adduction and abduction

Transverse Plane

Divides the body into superior and inferior portions; motions include internal and external rotation

Contraindication for ROM Assessment

A condition where ROM testing should not be performed because it may cause harm

Examples of ROM Contraindications

Dislocation region, unhealed fracture, post-surgical healing disruption, ossification

Precaution for ROM Assessment

A condition requiring caution during ROM testing

Examples of ROM Precautions

Painful conditions, inflamed/infected joints, pain medication use, muscle relaxers, osteoporosis, hypermobile joints, prolonged immobilization

AROM

Active Range of Motion; patient moves independently

PROM

Passive Range of Motion; examiner moves the patient

Qualitative Assessment During AROM

Willingness to move, ability to follow instructions/LOC, coordination, observable motion, pain, strength, functional ability

Qualitative Assessment During PROM

Amount of movement possible, limiting factors, pain changes, differences from AROM, capsular vs non-capsular patterns

Quantitative Assessment

Objective measurement of ROM using tools

Goniometer

Device used to measure joint angles

Goniometer Axis

Placed at the point of rotation for movement

Goniometer Stationary Arm

Aligned with the segment that does not move

Goniometer Movement Arm

Aligned with the segment that moves

Key Rule for Goniometer Use

Only the movement arm should move during testing

Inclinometer

Measures ROM relative to gravity

Advantage of Inclinometer

Requires only movement axis and is commonly available on smartphones

Tape Measure ROM Assessment

Measurement method sometimes used for ROM or swelling

General Principle of ROM Measurement

Reference criterion should remain on non-moving segment or gravity reference

Passive ROM Measurement Principle

Apply slight over-pressure at end range

Best Practice During ROM Measurement

Read measurement while device is still on patient

ROM Comparison Principle

Compare bilaterally

Common ROM Measurement Error

Reading the wrong side of the goniometer

Another Common ROM Measurement Error

Not correcting for start position

Observer Bias in ROM Measurement

Tendency to expect certain values or measurements ending in 0 or 5

Patient Positioning Error

Incorrect positioning or axis movement can affect accuracy

Most Reliable ROM Measurements

Same clinician, day/time, tool, position, and protocol

Firm End-Feel

Stretching soft tissue limits movement

Example of Firm End-Feel

Shoulder extension

Soft End-Feel

Soft tissue compressing against soft tissue

Example of Soft End-Feel

Elbow flexion

Hard End-Feel

Bone contacting bone

Example of Hard End-Feel

Elbow extension

Abnormal End-Feels

Early/late soft, early/late firm, early/late hard, spasm, empty, springy block

Empty End-Feel

No resistance because patient stops movement due to pain

Springy Block End-Feel

Rebound sensation preventing full motion

Capsular Pattern

Limitation in specific movements indicating capsule involvement

Examples of Causes of Capsular Patterns

Osteophytes and arthritic changes

Close-Packed Position

Position of maximal joint congruity and taut capsule/ligaments

Loose-Packed Position

Opposite of close-packed position

ROM Documentation Components

ROM type, side/body part, direction, start/end degrees, total ROM, subjective and objective findings, device used

Muscle Length Consideration in ROM

Tight muscles can contribute to decreased ROM

Passive Insufficiency

Shortening a muscle over one joint so it does not limit ROM at another joint

Effect of Knee Flexion During Hip Flexion Assessment

Flexing the knee reduces hamstring tension and increases hip flexion ROM

RROM

Resistive Range of Motion; screening tool following physiologic ROM

MMT

Manual Muscle Testing; scoring tool requiring positioning, gravity consideration, full ROM, and break testing

Purpose of Break Test

Distinguish 4/5 from 5/5 muscle strength

Break Test Instruction

“Hold this position, don’t let me break you”

Concentric Resistance Instruction

“Push/pull against my resistance as far as you can”

Eccentric Resistance Instruction

“Push/pull against my resistance, but let me win”

Static Contraction

Muscle contraction without movement

Dynamic Contraction

Muscle contraction with movement

Isometric Contraction

Muscle contracts without changing length

Isotonic Contraction

Muscle changes length while moving a load

Isokinetic Contraction

Muscle contracts at constant speed

Concentric Contraction

Muscle shortens during contraction

Eccentric Contraction

Muscle lengthens during contraction

Agonist

Primary muscle responsible for movement

Antagonist

Muscle opposing the agonist

Synergist

Muscle assisting the agonist

Neutralizing Synergist

Prevents unwanted movement during muscle action

Fixating/Stabilizing Synergist

Stabilizes a body segment during movement

MMT Procedure Step 1

Explain and instruct patient

MMT Procedure Step 2

Test uninvolved side or opposite direction first

MMT Procedure Step 3

Position patient based on gravity-dependent or gravity-eliminated testing

MMT Procedure Step 4

Support joint with bolster or towel if needed

MMT Procedure Step 5

Stabilize proximally

MMT Procedure Step 6

Apply resistance distally

MMT Procedure Step 7

Perform 2–3 repetitions

MMT Procedure Step 8

Perform break test if muscle grades 4/5

2-Joint Muscle

Muscle crossing and acting at two joints

Active Insufficiency

Muscle cannot generate full force because it is already shortened

Example of Active Insufficiency

Flexing the knee shortens the gastrocnemius, reducing its ability to plantarflex the ankle

Gastrocnemius

Plantarflexes the ankle and crosses the knee joint

Soleus

Plantarflexes the ankle but does not cross the knee joint