Key Takeaways
- The three anatomical planes are sagittal (divides left/right), frontal/coronal (divides front/back), and transverse (divides top/bottom)
- Flexion and extension occur in the sagittal plane; abduction and adduction occur in the frontal plane; rotation occurs in the transverse plane
- Special movements include dorsiflexion/plantarflexion (ankle), inversion/eversion (foot), pronation/supination (forearm), and protraction/retraction (scapula)
- Range of motion (ROM) can be active (client moves), passive (therapist moves), or resisted (against resistance)
- Normal gait cycle has two phases: stance phase (60% of cycle, foot on ground) and swing phase (40%, foot in air)
- Postural deviations include lordosis (excessive lumbar curve), kyphosis (excessive thoracic curve), and scoliosis (lateral spinal curve)
- Biomechanical assessment helps identify muscle imbalances that may cause pain or dysfunction
- Levers in the body consist of the fulcrum (joint), effort (muscle force), and resistance (load or body weight)
Joint Movements & Biomechanics
Understanding how the body moves through space is essential for massage therapists. Movement analysis helps identify restrictions, compensations, and the underlying causes of pain.
Anatomical Planes of Movement
All body movements can be described relative to three anatomical planes:
| Plane | Division | Movements | Axis of Rotation |
|---|---|---|---|
| Sagittal | Divides body into left and right halves | Flexion, extension, hyperextension, dorsiflexion, plantarflexion | Frontal (horizontal) axis |
| Frontal (Coronal) | Divides body into anterior and posterior halves | Abduction, adduction, lateral flexion, inversion, eversion | Sagittal (AP) axis |
| Transverse (Horizontal) | Divides body into superior and inferior halves | Rotation (medial/lateral), pronation, supination, protraction, retraction | Vertical (longitudinal) axis |
Joint Movements Defined
Sagittal Plane Movements
- Flexion: Decreasing the angle between two bones (e.g., bending the elbow)
- Extension: Increasing the angle between two bones (e.g., straightening the elbow)
- Hyperextension: Extension beyond the anatomical position (e.g., bending the head backward)
- Dorsiflexion: Bringing the top of the foot toward the shin (ankle)
- Plantarflexion: Pointing the toes downward (ankle)
Frontal Plane Movements
- Abduction: Moving a limb away from the midline of the body
- Adduction: Moving a limb toward the midline of the body
- Lateral flexion: Bending the trunk or neck to the side
- Inversion: Turning the sole of the foot inward (medially)
- Eversion: Turning the sole of the foot outward (laterally)
- Elevation: Moving a structure superiorly (e.g., shrugging shoulders)
- Depression: Moving a structure inferiorly (e.g., lowering shoulders)
Transverse Plane Movements
- Medial (internal) rotation: Rotating toward the midline
- Lateral (external) rotation: Rotating away from the midline
- Pronation: Rotating the forearm so the palm faces down (or posteriorly)
- Supination: Rotating the forearm so the palm faces up (or anteriorly)
- Protraction: Moving a structure anteriorly (e.g., rounding shoulders forward)
- Retraction: Moving a structure posteriorly (e.g., pulling shoulders back)
Multi-Plane Movements
- Circumduction: A combination of flexion, abduction, extension, and adduction in a circular pattern (e.g., drawing a circle with the arm at the shoulder)
- Opposition: Bringing the thumb to touch the fingertips (unique to the hand)
Range of Motion (ROM) Assessment
| Type | Description | What It Assesses |
|---|---|---|
| Active ROM (AROM) | Client moves the joint independently | Willingness to move, pain during movement, neuromuscular function |
| Passive ROM (PROM) | Therapist moves the joint while client relaxes | Joint integrity, capsular restrictions, end-feel |
| Resisted ROM (RROM) | Client contracts against therapist's resistance | Muscle strength, pain with contraction (may indicate muscle/tendon pathology) |
End-Feel
End-feel is the sensation the therapist perceives at the end of passive ROM:
| End-Feel | Sensation | Normal Example |
|---|---|---|
| Hard (bony) | Bone-to-bone contact | Elbow extension |
| Soft (tissue approximation) | Soft tissue compression | Knee flexion (calf meets thigh) |
| Firm (capsular) | Ligament/capsule stretch | Shoulder external rotation |
| Empty | Pain stops movement before physical limitation | Acute bursitis, fracture |
Posture Assessment
Common Postural Deviations
| Deviation | Description | Muscles Involved |
|---|---|---|
| Lordosis | Excessive lumbar curve (anterior pelvic tilt) | Tight: hip flexors, erector spinae. Weak: abdominals, gluteals |
| Kyphosis | Excessive thoracic curve (rounded upper back) | Tight: pectorals, anterior deltoid. Weak: rhomboids, middle trapezius |
| Scoliosis | Lateral curvature of the spine | Imbalance of paraspinal muscles on both sides |
| Forward head posture | Head positioned anterior to shoulders | Tight: SCM, suboccipitals, upper trapezius. Weak: deep neck flexors |
| Upper crossed syndrome | Combination of rounded shoulders and forward head | Tight: upper trapezius, levator scapulae, pectorals. Weak: deep neck flexors, lower trapezius, serratus anterior |
Gait Analysis
The gait cycle is the sequence of movements from one foot striking the ground to the same foot striking the ground again.
| Phase | % of Cycle | Description |
|---|---|---|
| Stance phase | ~60% | Foot is in contact with the ground |
| Swing phase | ~40% | Foot is off the ground, swinging forward |
Key Gait Observations
- Antalgic gait: Shortened stance phase on the painful side
- Trendelenburg gait: Hip drops on the unsupported side (weak gluteus medius)
- Excessive pronation: Foot rolls inward too much during stance
- Arm swing: Should be rhythmic and opposite to leg movement
Levers in the Human Body
The body uses three classes of levers for movement:
| Class | Arrangement | Example | Mechanical Advantage |
|---|---|---|---|
| First class | Fulcrum between effort and resistance | Head nodding on atlas (C1) — fulcrum at atlanto-occipital joint | Balanced |
| Second class | Resistance between fulcrum and effort | Standing on tiptoes — fulcrum at toe joints, resistance is body weight, effort at calcaneus | Favors force (power) |
| Third class | Effort between fulcrum and resistance | Biceps curl — fulcrum at elbow, effort at biceps insertion on radius, resistance at hand | Favors speed/ROM (most common in the body) |
Key concept: Third-class levers are the most common in the human body. They sacrifice mechanical advantage (force) for increased speed and range of motion, which is why muscles must generate much more force than the weight being moved.
Muscle Fiber Types
Understanding muscle fiber types helps explain differences in muscle function and exercise response:
| Fiber Type | Name | Characteristics | Function | Example Muscles |
|---|---|---|---|---|
| Type I | Slow-twitch (oxidative) | Fatigue-resistant, aerobic, red color (rich in myoglobin) | Endurance activities, postural support | Soleus, erector spinae |
| Type IIa | Fast-twitch (oxidative-glycolytic) | Moderate fatigue resistance, mix of aerobic/anaerobic | Moderate-intensity, sustained activities | Varied — depends on training |
| Type IIx | Fast-twitch (glycolytic) | Fatigue quickly, anaerobic, white/pale color | Explosive, powerful, short-duration movements | Lateral gastrocnemius, triceps |
Clinical relevance: Muscles with primarily Type I fibers (like the soleus and deep postural muscles) are prone to developing tightness and hypertonicity. Muscles with primarily Type II fibers are more prone to weakness and inhibition. This pattern informs treatment approaches.
Flexion and extension occur in which anatomical plane?
Turning the forearm so the palm faces downward is called:
A client has excessive lumbar curvature (lordosis). Which muscles are most likely TIGHT?
During passive range of motion assessment, the therapist feels a hard, abrupt stop at the end of elbow extension. This end-feel is classified as:
Approximately what percentage of the gait cycle is spent in the stance phase?
Match each joint movement to its correct anatomical plane.
Match each item on the left with the correct item on the right
Arrange the types of range of motion (ROM) assessment in the typical order they are performed during a client assessment.
Arrange the items in the correct order
Upper crossed syndrome involves tight pectorals and upper trapezius combined with weak:
Third-class levers are the most common in the human body because they:
Muscles with primarily Type I (slow-twitch) fibers are prone to developing ___ and hypertonicity.
Type your answer below
Circumduction is a multi-plane movement that combines: