Lesson 3: Joint Actions
by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS
Video #3: Joint Actions
Joint Actions -
- describes motion occurring at joints. Much like anatomical directions, these terms are specific language (jargon), used to communicate joint motion between human movement professionals. Joint actions are specific to Planes of Motion and in most cases are labeled relative to the Anatomical Position.
Sagittal Plane Joint Actions:
- Flexion – A decrease in joint angle (in the sagittal plane)
- Extension – An increase in joint angle (in the sagittal plane)
Sagittal Plane Joint Actions - http://biomechanics.byu.edu
Frontal Plane Joint Actions:
- Abduction - Movement away from the midline of the body (in the frontal plane).
- Adduction - Movement toward the midline of the body (in the frontal plane).
- Lateral Flexion – Displacement of the trunk away from the midline in the frontal plane (in the frontal plane).
Frontal Plane Joint Actions Note: Pay careful attention to Abduction, Adduction & Lateral Flexion - Eversion, inversion, radial and ulnar deviation will in later courses in conjunction with the muscles crossing the wrist and ankle - http://biomechanics.byu.edu
Transverse Plane (Horizontal Plane) Joint Actions:
- External (lateral) Rotation - Movement of the anterior side of a segment away from the midline of the body.
- Internal (medial) Rotation - Movement of the anterior side of a segment toward the mid-line of the body.
- Horizontal Adduction (flexion) – Horizontal motion that results in movement toward the midline.
- Horizontal Abduction (extension) – Horizontal motion that results in movement away from the midline.
Transverse Plane Joint Actions - http://biomechanics.byu.edu
Activity #1: Identify the Joint Actions on the Lesson 2 Activity:
If you printed and filled-in the graph from Lesson 2 (Selecting Exercises for each plane), follow the directions below (this activity