1) The document defines three types of motion - translation, angular, and general - and describes anatomical reference positions, planes, axes, and directional terms used to qualitatively analyze human movement. 2) It provides details on planar movements including flexion/extension, abduction/adduction, and internal/external rotation in the sagittal, frontal, and transverse planes respectively. 3) Qualitative analysis of human movement involves descriptive observation of technique and performance to identify causes of problems and differentiate unrelated factors, and the document outlines steps to plan and conduct such an analysis.

1. Qualitative Analysis of Motion
Objectives:
• Define the 3 types of motion
• Identify the reference position, planes,
and axes associated with the human body
• Learn the terminology used to qualitatively
describe directions and joint motions
• Learn how to plan & conduct a qualitative
analysis of human movement
Translation (or Linear Motion)
• All parts of an object or system move the same
distance in the same direction at the same time
Rectilinear Motion Curvilinear Motion
translation along a translation along a
straight line curved line
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2. Angular Motion
• All points in an object or system move in a circle
about a single axis of rotation. All points move
through the same angle in the same time
Axis of rotation
• Axis of Rotation
– imaginary line that the object spins about
– oriented perpendicular to the plane of rotation
General Motion
• A combination of translation and rotation
• Most human movement consists of general
motion
(Hall, 2003)
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3. Anatomical Reference Position
Starting position for describing body segment
movements and measuring joint angles
(i.e. all joint angles = 0)
Reference position:
• Erect standing
• Feet separated slightly
and pointed forward
• Arms hanging at the
sides
• Palms facing forward
Directional Terms
Superior closer to the head
Inferior farther from the head
Anterior toward the front of the body
Posterior toward the back of the body
Medial toward the midline of the body
Lateral away from the midline of the body
Proximal closer to the trunk
Distal away from the trunk
Superficial toward the surface of the body
Deep away from the surface of the body
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4. Anatomical Reference Planes
• Three imaginary perpendicular planes that
divide the body in half by mass
Sagittal Frontal
(coronal)
divides into divides into
right and left front and back
halves halves
Transverse
(horizontal)
divides into upper and lower halves
Planar Movements
• Movement is said to occur within a plane if the
movement is parallel to the plane
Sagittal Frontal
Motion Motion
forward/back right/left
up/down up/down
Transverse
Motion
forward/back; right/left
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5. Anatomical Reference Axes
• Imaginary lines about which rotations occur
• Pass through a joint’s center of rotation
• In reference position, are perpendicular to anatomical
planes
Mediolateral Anteroposterior
axes for axes for
sagittal plane frontal plane
rotations rotations
Longitudinal
axes for transverse plane rotations
Sagittal Plane Movements
• Flexion
Anterior-directed rotation with respect to proximal segment
Exceptions:
– Posterior-directed rotation of leg with respect to thigh
– Upward rotation of the foot (ankle dorsiflexion)
• Extension (Hall, 2003)
(& ankle plantarflexion)
Opposite of flexion
• Hyperextension
Extension beyond the
anatomical position
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6. Frontal Plane Movements
• Abduction (& wrist radial deviation)
Laterally-directed rotation of longitudinal axis with respect
to proximal segment
Exception: Trunk right & left lateral flexion
• Adduction (Hall, 2003)
(& wrist ulnar deviation)
Opposite of abduction
• Elevation & Depression
of the shoulder girdle
Transverse Plane Movements
• Internal Rotation (& forearm pronation, ankle eversion*)
Medially-directed rotation of anterior aspect (or foot dorsal
surface) with respect to proximal segment
Exception: Head and trunk right & left rotation
(Hall, 2003)
• External Rotation
(& forearm supination,
ankle inversion*)
Opposite of internal
rotation
• Foot Abduction &
Adduction
* frontal plane movements Internal External
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7. Multiplanar Movements
The structure/geometry of most joints allows
movement in multiple planes simultaneously
Examples:
• Hip: (3 planes)
flexion/extension, abduction/adduction,
internal/external rotation
• Wrist: (2 planes)
flexion/extension, abduction/adduction
• Subtalar joint: (3 planes)
pronation (dorsiflexion, abduction, eversion)
supination (plantarflexion, adduction, inversion)
Planar vs. Multiplanar Skills
primarily
planar
skills
multiplanar
skills
(Hall, 2003)
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8. Qualitative Analysis
• Based on the descriptive observation of:
– technique
– performance outcome
• Role of biomechanics:
– Understand mechanical requirements of task
– Identify underlying cause of problem in
technique or performance
– Differentiate unrelated factors
Planning a Qualitative Analysis
1. What are major questions to be answered?
2. Determine the optimal viewing perspective(s)
3. Identify appropriate viewing distance
4. How many trials / executions needed?
5. Performer’s attire
6. Select an appropriate environment
7. Visual observation or video camera?
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9. Conducting a Qualitative Analysis
(Hall, 2003)
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