ENT 214 Biomechanics KINEMATIC CONCEPTS FOR ANALYZING HUMAN

ENT 214 Biomechanics KINEMATIC CONCEPTS FOR ANALYZING HUMAN MOTION Mohd Yusof Baharuddin BBiomed. Eng(UM) MBiomed. Eng(Melbourne) myusof@unimap. edu. my Picture from Mister. Bisson Flickr pages

OBJECTIVES Ø Ø Ø Identify and describe the reference positions, planes, and axes associated with the human body. Define and appropriately use directional terms and joint movement terminology. Identify and describe the uses of available instrumentation for measuring kinematics quantities.

Anatomical reference position Ø erect standing position with all body parts facing forward Ø considered the starting point for all body segment movements

BODY SEGMENT NAMES APPENDICULAR • The lower and upper extremity • Away from trunk become smaller, • faster and their movement • is difficult to observe AXIAL • Accounting 50% of body weight • Moves slower the other parts of the body pe ra rm Forearm Hand NECK Thigh Leg Foot Lower Extremity TRUNK Upper Extremity Head Up

Directional terms: Ø superior: closer to the head Ø inferior: further away from the head Ø anterior: toward the front of the body Ø posterior: toward the back of the body

Directional terms: Ø medial: toward the midline of the body Ø lateral: away form the midline of the body Ø proximal: closer to the trunk Ø distal: away from the trunk

Directional terms: Ø superficial: toward the surface of the body Ø deep: inside the body away from the surface

Reference planes Ø sagittal plane - in which forward and backward movements occur Ø frontal plane - in which lateral movements occur Ø transverse plane - in which rotational movements occur

Reference axes Ø mediolateral axis - around which rotations in the sagittal plane occur Ø anteroposterior axis - around which rotations in the sagittal plane occur Ø longitudinal axis - around which rotational movements occur

Forms of motion Linear motion: motion along a line Ø Rectilinear motion: (along a straight line) Ø Curvilinear motion: (along a curved line)

Forms of motion Angular motion: rotation around an axis

Forms of motion: LINEAR + ANGULAR = GENERAL General motion: a combination of linear and angular motion (includes most human motion)

What is a mechanical system? Ø a body or portion of a body that is deliberately chosen by the analyst Ø examples: throwing arm, kicking leg, the trunk during performance of a lift, the entire body during performance of a maximal vertical jump

What movements occur in the sagittal plane? Ø flexion Ø extension Ø hyperextension Flexion Extension Hyperextension Ø dorsiflexion Ø plantar flexion Dorsiflexion Plantar flexion

What movements occur in the frontal plane? Ø abduction & adduction Ø lateral flexion Lateral flexion Abduction Adduction

What movements occur in the frontal plane? Ø Ø Ø elevation & depression inversion & eversion radial & ulnar deviation Elevation Radial deviation Ulnar deviation Depression Eversion Inversion

What movements occur in the transverse plane? Ø left & right rotation Ø medial & lateral rotation Medial rotation Lateral rotation

What movements occur in the transverse plane? Øsupination & pronation Ø horizontal abduction & adduction Horizontal abduction Pronation Supination

Spatial Reference Systems Ø useful for standardizing descriptions of human motion Ø most commonly used is the Cartesian coordinate system Ø human body joint centers are labeled with numerical x and y coordinates

Spatial Reference Systems Y (x, y) = (3, 7) (0, 0) X Cartesian coordinates of the hip

Spatial Reference Systems y x=y=+ x=+ y=+ x (0, 0) x=y=- x=+ y=- Coordinates can be both positive and negative.

Qualitative Analysis: Planning Ø performer attire Ø lighting conditions Ø background Ø use of video

Qualitative Analysis: Conducting the Analysis Identify Question/Problem Viewing Angle Viewing Distance Performer Attire Refine Question Make Decisions Use of Video End Analysis Communicate with Performer Environmental Modifications Collect Observations Visual Auditory From Performer Interpret Observations From Other Analysts

TOOLS FOR MEASURING KINEMATIC QUANTITIES Objective: To determine the coordinates of the marked points as a function of time Direct Measurement Techniques – – – Goniometers Special Joint Angle Measuring Systems Accelerometers Indirect Measurement (Imaging) Techniques – – Cinematography Television Optoelectric technique Others indirect measurement

TOOL FOR KINEMATICS MEASUREMENT OPTICAL SYSTEM Cinematography (movie cameras) Type of film use depend on lighting available. Television ØThe major difference between Cinematography and Television is the frame rate (The number of images that are shown or sent each second) ØTelevision has high enough field rate for most movement, but too low for quantitative analysis of rapid athletic movement. v. Standard video camera – reflective marker produces a trailing edge and blurs image when there is a rapid movement. v. CCD cameras – eliminates both blurring and skewing v. Infrared cameras – reflected infrared lights from the markers is the only lights picked up by the camera.

Optoelectric Techniques – optical • Subject wear tiny infrared lights on each desired anatomical landmarks. • The lights were flashed sequentially, and detected on a special camera. Non Optical techniques l l l Magnetic System – Sensors are linked by cables to a computer. Electromagnetic System – the subjects wear a body suit. Acoustic Systems –Sonar uses reflected sound waves.

Advantages and Disadvantages of Optical Systems Advantages ØMost systems are not limited to the numbers of markers used. ØEncumbrance to movement is minimal (lightweigth reflective markers). ØInexpensive (VCR and TV cameras). ØTV and Cine can be replayed for teaching purposes or for qualitative analysis of the total body movement. Disadvantages ØMost multiple cameras are expensive. ØSome imaging system cannot be used outdoor.

QUALISYS TRACK MANAGER Oqus camera Control cable USB cable (A/D 16 channel to computer) Analogue to Digital 16 channel USB module Forceplate external amplifier AC/DC power supply 6 channel analogue output cable BNC cable

QUALISYS TRACK MANAGER Calibration frame markers