Serve -Is raising the hitting shoulder the last big stretch?

[Chas Tennis]

Serve - Is raising the hitting shoulder the last big stretch?

Background - My interpretation of some biomechanical research results on the serve-

During the service motion, first, the tossing shoulder is up and the hitting shoulder is down. Then the hitting shoulder is very rapidly moved high using trunk lateral flexion. Last, the final racket head speed is increased to ball impact using mostly internal shoulder rotation. Internal shoulder rotation contributes the most to racket head speed.

The internal shoulder rotators are pre-stretched by the leg thrust. The stretch occurs because the upper arm is at about 90° to the body and the racket and forearm are at about 90° to the upper arm when the legs thrust up and carry along the shoulder. This externally rotates the shoulder stretching the internal shoulder rotator muscles. The internal shoulder rotator muscles are the lat (Latissimus Dorsi), pec (Pectoralis Major), Teres Major and some others. The largest muscle connected to the arm is the lat, the second largest is the pec. Both insert on the front of the upper arm at the same location and internally rotate the shoulder by pulling on the humerus at that insertion point.

The question is what part does raising the hitting shoulder play in farther stretching the lat or in maintaining the stretch?

Apparently it is well known that raising the shoulder can increase the lat stretch.

From the Manual of Structural Kinesiology, C. Thompson, R. Floyd, 15th ed., page 89:

paraphrasing

The stretch (of the lat) may be increased ................by then laterally flexing and rotating the trunk to the opposite side.

(This is a great basic reference. It is a popular college text and the latest edition is $75 while the recent editions like the 15th are just $10 or so.)

Lateral trunk flexion is just the side bend that puts the hitting shoulder up. Rotation of the trunk is just the trunk turn that is used for serving. Both of these lat stretches can easily be felt by just holding the upper arm at 90° to the body and rotating the forearm up and back as in the service motion to give the internal rotators some stretch. When stretched in that way, laterally(side) bend the trunk, feel the lat stretch. Also rotate the trunk and feel the lat stretch.

In Knudson's book, Biomechanical Principles of Tennis Technique, I think he discusses the speed of stretched muscles as more rapid.

Does this late trunk flexion and rotation play an important part for the serve by final stretching of the lat for added racket head speed?

 

[LeeD]

Maybe you should look at throwing a ball. You are waay overthinking a simple motion. Learn to serve, not learn what is behind the mechanics of serving.
OTOH, this thread is a nice excercise in useless information, so it should draw plenty of replies, most very good reading.

 

[TennisCJC]

Yes, throw a heavyball like a football to get the feel and don't over think it.

If that doesn't work, isolate a few key points in the serve, like get the front arm and shoulder up and hitting "up the mountain" as you go up and into contact.

If that doesn't work, see a pro for some lessons to debug your serve.

 

[tricky]

The question is what part does raising the hitting shoulder play in farther stretching the lat?

Mmm, the casual relation itself is actually in reverse. The lat stretches due to the tilt of the trunk, and the tilt of the trunk is partially effected by the tossing motion (if the hips are loading.) When the lats stretches, this causes a shoulder adduction, but as the eccentric phase.

What happens with many servers is that they self-consciously form the trophy pose by lifting the shoulder, as if making a touchdown gesture. When they do this, they break the kinetic chain from the trunk to the shoulder. Not only does it weaken the serve, but it throws off the timing of the motion.

It all comes together if your toss is good, and your weight moves into court from the beginning of the toss.

 

[Chas Tennis]

................. The lat stretches due to the tilt of the trunk, and the tilt of the trunk is partially effected by the tossing motion (if the hips are loading.) When the lats stretches, this causes a shoulder adduction, but as the eccentric phase.

What happens with many servers is that they self-consciously form the trophy pose by lifting the shoulder, as if making a touchdown gesture. When they do this, they break the kinetic chain from the trunk to the shoulder. Not only does it weaken the serve, but it throws off the timing of the motion.
......................

I am trying to identify all stretch details of the lat associated with motions of the serve.

Here is some more detail. I'd be interested in how the points that you mentioned correspond to these points.

This description from the Manual of Structural Kinesiology is not for the serve but in general identifies some motions and their effect on stretching the lat. These motions are all present in the serve, in fact, the description reads like part of the service motion.

"The latissimus dorsi is stretched with the teres major when the shoulder is externally rotated while in a 90-degree abducted position. This stretch may be accentuated further by abducting the shoulder fully while maintaining external rotation and then laterally flexing the trunk and rotating the trunk to the opposite side."

Breakdown-

1) "The latissimus dorsi is stretched with the teres major when the shoulder is externally rotated while in a 90-degree abducted position."

The corresponding parts of the service motion are 1) the upper arm aligned with the line between the shoulders ("90-degree abducted position"). 2) External rotation occurs from the shoulder external rotators and also because the forearm and racket are bent, say, at very roughly 90 degrees to the upper arm when the legs thrust up. The inertia of the forearm and racket stretch the internal shoulder rotators.

2) ......"This stretch may be accentuated further by abducting the shoulder fully while maintaining external rotation..."

There is no corresponding part of the serve because it does not occur in proper technique since farther abducting the shoulder results in more risk of impingement. (McLennan & Ellenbecker videos on shoulder injury) The upper arm should remain in a rough line with line between the shoulders.

3) "...while fully maintaining the external rotation and then laterally flexing the trunk ......................"

The corresponding part of the serve is the lateral trunk flexion that brings down the tossing shoulder and raises the hitting shoulder. Probably starting, as often recommended, with the front hip bowed forward allows more range of trunk flexion and therefore greater lat stretch. ? I have not seen another clear explanation as to why having the hip forward would help the serve.

4) "while fully maintaining the external rotation and then .........rotating the trunk to the opposite side."

The corresponding part of the serve would be 'body turn' (sometimes loosely called 'shoulder turn.') Rotating the trunk can stretch the lat. Also, pointing the chest up, stretching the lat, and then rotating the trunk forward can farther stretch the lat. This may account for the 'chest up' recommendation often heard. Otherwise, what is the reason?

I have sort of a stretch-then release viewpoint where the lat muscle is first stretched for internal shoulder rotation and then released. Maybe some of these stretching motions could also drive the serve very fast more directly. ?

 

[decades]

there is a bill tilden teaches the serve video floating around. he isn't thinking about bio mechanics. if we all could just capture that fluidity.

 

[CRWV]

... a nice excercise in useless information...

LeeD
G.O.A.T.
Join Date: Dec 2008
Posts: 15,858

Guy wasn't looking for good advice about his tennis playing, he asked a specific question. (an interesting one, at that)

 

[Chas Tennis]

Thoracic Extension/Flexion along with raising the hitting shoulder move the origins and insertions of muscles, especially the lat, and may affect the stretch of muscles or the forces applied to the upper arm (humerus).

See also thread

Thoracic Extension of the Spine and the Serve

WARNING - How your spine is used during the serve can risk injury. Many backs are not capable of much Thoracic Extension. ? http://www.racquetfit.com/articles/Screening/if_you_can%27t_extend_from_your_thoracic_spine_you%27re_squandering_power_and_inviting_injury The extension of the...

tt.tennis-warehouse.com

"Thoracic Extension then Thoracic Flexion on the tennis serve (slice). Timing.

Use full screen. Single frame on Youtube use the "."& "," keys.
This video has brief messages that last only a few frames.
1) Leg Thrust Starts (at 408ms)
2) Maximum Thoracic Extension (at 133ms)
3) Near Straight Back (at 50ms)
The back goes from 2) to 3) in 83 milliseconds (100ms = 1/10 second).

With 4 second pauses on frame with messages.
Thoracic Extension then Thoracic Flexion on the tennis serve (slice). Timing.

"

 

[LeeD]

Drop toss arm hard, rotation takes over.

 

[user92626]

Way too many words to describe an action.

Can you keep this image in your mind when you contact the ball?

Whatever you do, try to get into this position. Good?

 

[Chas Tennis]

I believe that this is the image to keep in mind for understanding the biomechanics of the serve around 100 milliseconds before impact.
1) the shoulder blade is rising and that lengthens the distance between the lat's origin and insertion on the upper arm.
2) at about the same time Thoracic Extension or Flexion is occurring and those also affect the distance between the lat's origin and insertion.
3) Final motion of upper arm is ISR and maybe other shoulder joint motions for racket head speed.

Consider that distance and go frame-by-frame through the videos in post #8. Federer has straightened his back in the frame of your post so that is later than the Thoracic Extension/Flexion cycle, maybe after impact?