Joint Actions

 by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS

Joint Actions -

- describe motion occurring at joints.  Much like anatomical directions, these terms are specific language (jargon) used to communicate motion between 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 is similar to the class activity in the video above):

• Note: If you did not do the graph in Lesson 2, skip to Activity #2

1. Under the Plane of Motion write in the joint actions associated with that plane
2. Next to each exercise write out the associated joint actions

• Sample of Activity
• Answer Key

Activity #2: Joint Action Graphs

• Note: If you did Activity #1, it is not necessary to do Activity #2; however, the additional practice may be beneficial

1. Fill in on the joint actions available for the joint listed (Hint: one joint action per box).
2. Name the plane that each joint action is associated with.
3. List an exercise you are familiar with that is an example of that joint action.
4. The first joint action graph has been filled out for you in red as an example.

Printable PDF of Graphs Below: Joint Actions Graphs

Answer Key: Joint Actions Graphs Answer Key

Elbow Joint
Action	Plane	Exercise Example
Flexion	Sagittal	Bicep Curl
Extension	Sagittal	Tricep Extension

Knee Joint
Action	Plane	Exercise Example

Shoulder
Action	Plane	Exercise Example

Hip
Action	Plane	Exercise Example

Spine
Action	Plane	Exercise Example