Internal Rotation (a.k.a. Medial Rotation): A rotational (spinning) movement in which the anterior side of a segment moves toward the mid-line of the body in the transverse plane.

• Opposing Joint Action: External Rotation
• Plane of Motion: Transverse (Horizontal) Plane
• Direction Bias: Inward
• Note: Joint actions may be referred to as "osteokinematic motions" or "osteokinematic joint actions" to differentiate them from "arthrokinematic motions " (e.g., spin, glide, roll, compression, and distraction).

For more (including a video lecture), check out:

• Lesson 3: Joint Actions

Joints that Perform Internal Rotation (and Sample Exercises):

1. Shoulder joint (Glenohumeral joint): Internal rotation occurs when the humerus rotates so that the anterior surface rotates toward the midline, as observed during internal rotator/subscapularis activation exercises .
2. Hip Joint (Pelvifemoral Joint): Internal rotation happens when the femur moves so that the anterior surface of the thigh rotates toward the midline, as observed during the goniometric assessment of hip internal rotation range of motion (ROM) .
3. Knee joint (Tibiofemoral joint): While subtle, internal rotation can occur when the knee is bent. This happens when the anterior surface of the tibia (shinbone) rotates toward the midline of the body relative to the femur. This may be observed during tibial internal rotator activation .