The basis of communication is done through anatomical positional terms. Learning these terms will give us a common language and increase your knowledge with the common words used in this field. Note: this is not a complete list, but it will start you on the right path.

Scapula (aka shoulder blade)

Retraction (i.e. Front Lever) the scapula is squeezed together. This will also create a small natural supination of the forearm.
Protraction (i.e. Planche) the scapula is pushed away from each other. This will also create a small natural pronation of the forearm
Elevation (i.e. Handstand) the scapula is moved directly up, to bring the shoulders to the ears
Depression (i.e. Support) the scapula is pressed down, to bring the shoulders towards the lower spine
Upward Rotation (i.e.Lateral Raise Up) the scapula moves up and slightly rotates outward as the arm moves up toward overhead
Downward Rotation (i.e. Lateral Raise Down) the scapula moves down and slightly rotates inward as the arm moves down toward the floor

Pelvis

Posterior Pelvic Tilt (PPT) the pelvis is rotated forward, tucking the butt in (contracting the glutes) and creating a rounding of the lower back
Anterior Pelvic Tilt (APT) the pelvis is rotated backward, sticking the butt out (relaxing the glutes) and creating an arch of the lower back

Forearm

Supination (i.e. Chinup) the palm is rotated up as to face towards yourself, this will create a natural and small amount of humeral external rotation
Pronation (i.e. Pullup) the palm is rotated down as to face away from yourself, this will create a natural and small amount of humeral internal rotation

Arm/Leg Relationship

Ipsilateral (same side) meaning the same side leg and arm are working together. If the right leg is forward then the right arm is forward. I.e. throwing a ball
Contralateral (opposite side) meaning the opposite side leg and arm are working together. If the right leg is forward then the left arm is forward. I.e. walking

Joint Movement

Flexion joint is moving closer to the body. I.e. bending the knee towards the butt
Extension joint is moving further away from the body. I.e. straightening the knee
External Rotation the joint is rotating away from the center of the body.
Internal Rotation the joint is rotating toward the center of the body.
Adduction the appendage is moving toward the body. I.e. Leg comes from away from second leg, to closer to second leg
Abduction the appendage is moving away from the body. I.e. Leg comes from close to the second leg, to further away from the second leg

Planes of Movement

Sagittal (i.e. back squats, vertical jumping, walking) Movements in this plane of motion are done forward and backward only. No twisting or side flexion would be used.
Coronal or Frontal (i.e. side bending, adduction and abduction) Movements in this plane of motion are done laterally with the body. No twisting or forward/backward motion will be used.
Transverse or Horizontal (i.e. spinal or hip rotation, pushups) Movements in this plane of motion are done rotationally. *note any adduction or abduction done at 90degrees is also considered to be in the transverse plane (like the pushup)