Chas Stumpfel
Active
Coach
Video Library (13 videos)
| Name |
FPS |
Duration |
Internal Shoulder Rotation: Key to Serving Power (1 of 6)
Chas Stumpfel’s internal shoulder rotation animation for the serve, filmed from a neutral instructional angle. The animation clearly separates trunk coil from upper arm motion so you can see the shoulder internally rotate only after the torso has begun to uncoil in the kinetic chain.
|
|
11.4s |
Setting Up the Shoulder Rotations on a World Class Serve (1 of 7)
Chas Stumpfel’s serve biomechanics animation from a central baseline position, filmed from a side/court-level angle. The sequence clearly depicts the racket face closing as it approaches contact, with the ball struck slightly above head height as the racket head accelerates upward along the swing path.
|
|
8s |
Internal Shoulder Rotation: Key to Serving Power (2 of 6)
Chas Stumpfel’s external shoulder rotation animation for the serve, filmed from a neutral instructional angle. The hips and legs are shown in a stable base with moderate knee bend, emphasizing how a grounded lower body supports upper-body rotation without excessive hip turn.
|
|
12.3s |
Setting Up the Shoulder Rotations on a World Class Serve (2 of 7)
Chas Stumpfel’s 2Animation5Motions serve biomechanics animation from a neutral court position, filmed from a side/sagittal angle. The animation clearly separates the timing of shoulder external rotation, trunk coil, and uncoil so you can see how upper trunk rotation lags behind hip rotation before accelerating into contact.
|
|
14.6s |
Internal Shoulder Rotation: Key to Serving Power (3 of 6)
Chas Stumpfel’s internal shoulder rotation animation for the serve from a neutral reference position, filmed from a side biomechanical angle. The animation clearly depicts the racket-hand wrist staying relatively firm while the rapid internal shoulder rotation drives racket head speed, with minimal independent wrist snap at contact.
|
|
10.1s |
Setting Up the Shoulder Rotations on a World Class Serve (3 of 7)
Chas Stumpfel’s serve biomechanics animation focuses on the upper arm and shoulder action, viewed from a neutral, instructional camera angle. The animation clearly emphasizes how the wrist stays relatively loose while the upper arm and shoulder drive the motion, with pronation occurring late as the racquet approaches contact.
|
|
6.8s |
Setting Up the Shoulder Rotations on a World Class Serve (4 of 7)
Chas Stumpfel’s serve biomechanics animation from a neutral court position, filmed from a side view. The animation clearly depicts how the shoulder line and trunk progressively coil as the legs drive up, then uncoil in sequence from the ground through the hips and torso into the serving arm.
|
|
9s |
Internal Shoulder Rotation: Key to Serving Power (4 of 6)
Chas Stumpfel’s external shoulder rotation segment in the serve motion, filmed from a biomechanics-focused instructional angle. His follow-through brings the hitting arm up and back while the torso continues rotating, and he quickly re-centers his weight to a neutral stance ready to progress into the rest of the kinetic chain.
|
|
13.5s |
Internal Shoulder Rotation: Key to Serving Power (5 of 6)
Chas Stumpfel’s serve biomechanics animation from a central baseline position, filmed from a side/court-level angle. The animation clearly depicts the timing of the leg drive into a strong shoulder-over-shoulder motion with an open-to-neutral landing stance on the front foot.
|
|
11.8s |
Setting Up the Shoulder Rotations on a World Class Serve (5 of 7)
Chas Stumpfel’s serve torso turn animation from a neutral position, filmed from a side angle. The follow-through clearly continues the torso rotation toward the court with the non-hitting arm dropping and the body weight transferring forward into a balanced landing stance.
|
|
7.5s |
Internal Shoulder Rotation: Key to Serving Power (6 of 6)
Chas Stumpfel’s serve contact animation from a neutral position, filmed from a side biomechanical angle. The racket face is slightly tilted forward at contact with the ball just above shoulder height, clearly illustrating rapid internal shoulder rotation driving racket head speed through the hitting zone.
|
|
11.1s |
Setting Up the Shoulder Rotations on a World Class Serve (6 of 7)
Chas Stumpfel’s serve biomechanics animation focusing on shoulder tilt, viewed from a side angle. The animation clearly depicts the upward tilt of the front shoulder relative to the back shoulder during the loading phase, emphasizing how this alignment is established before initiating the upward swing.
|
|
7.8s |
Setting Up the Shoulder Rotations on a World Class Serve (7 of 7)
Chas Stumpfel’s serve biomechanics animation from a neutral position, filmed from a side angle. The animation clearly depicts strong knee flexion into the loading phase and an explosive upward leg drive that propels the hips into a pronounced forward and upward thrust.
|
|
11.7s |
