nodot nodot
Tennis SET
November 2004 Article

Latest Tennis SET Article

Tennis SET Archive

Send a message to Jani

Tennis Server

Do You Want To Be A Better Tennis Player?

Then Sign Up For A Free Subscription to the Tennis Server INTERACTIVE
E-mail Newsletter!

Tom Veneziano You will join 13,000 other subscribers in receiving news of updates to the Tennis Server along with monthly tennis tips from tennis pro Tom Veneziano.
Best of all, it is free!

Tennis Features Icon TENNIS FEATURES:

TENNIS ANYONE? - USPTA Pro John Mills' quick player tip.
TENNIS WARRIOR - Tom Veneziano's Tennis Warrior archive.
TURBO TENNIS - Ron Waite turbocharges your tennis game with tennis tips, strategic considerations, training and practice regimens, and mental mindsets and exercises.
WILD CARDS - Each month a guest column by a new writer.
BETWEEN THE LINES - Ray Bowers takes an analytical and sometimes controversial look at the ATP/WTA professional tour.
PRO TENNIS SHOWCASE - Tennis match reports and photography from around the world.
TENNIS SET - Jani Macari Pallis, Ph.D. looks at tennis science, engineering and technology.
MORTAL TENNIS - Greg Moran's tennis archive on how regular humans can play better tennis.
HARDSCRABBLE SCRAMBLE - USPTA pro Mike Whittington's player tip archive.

Tennis Community Icon TENNIS COMMUNITY:

Tennis Book, DVD, and Video Index
Tennis Server Match Reports
Editor's Letter
Become a Tennis Server Sponsor

Explore The Tennis Net Icon EXPLORE THE TENNIS NET:

Tennis News and Live Tennis Scores
Tennis Links on the Web
Tennis SET
Green Dot
Tennis Warehouse Logo
Green Dot

Warm Up, Stretch and Flexibility - The Debate: Part II

Jani Macari Pallis, 
Ph.D. Photo
Jani Macari Pallis, Ph.D.

In our initial discussion on "Warm Up, Stretch and Flexibility - The Debate," we reviewed and discussed the basic issues of the problem. Specifically, while warm up is important before play and exercise in general, current research argues that:

  • greater static flexibility does not always decrease the risk of muscular injury;
  • flexibility and stretching may be unrelated to injury risk;
  • stretching has minimal effect of the stiffness of muscle, decreases muscular performance, and modifies the energy recovery of stretched muscle.

Due to the subtleties in some of the meanings of the words "stretching," "warm up," and "flexibility" we reviewed the definitions.

Bottom line: Warm up is important and beneficial; however stretching within the warm up does not furnish the presumed benefits of injury reduction and enhanced muscle performance.

What does stretching do and what are its benefits? What happens to your body when you stretch?

The training (long-term) effects of stretching are beneficial to static flexibility and to performance. Stretching can increase range of motion (static flexibility). Knudson [1] reported stretching increases of 5-20% in static flexibility, although the effects require several weeks to obtain and are short-lived (you need to stick with it or you lose what you have gained).

Short-term increase in static flexibility appears to be largely related to the person's tolerance to the discomfort of a stretching position, not major changes in the material properties of the muscle/tendon. Another caveat to this is that passive stretching (using an external force - often a person) can cause a large amount of tension on the muscle (extension). Vigorous, forceful stretching can weaken and injure muscles by stretching ligaments or creating unsafe loads.

Normal static flexibility refers to "typical" limits in the joint movement between the extreme positions (i.e., range of motion). Those with low or a loss of range of motion (inflexible, anklyosis) and those with an inordinately high range of motion (hypermobile) also have higher injury rates [1]. In the case of those with an extreme range of motion, the cause may be that greater range of motion and less tissue resistance causes a greater instability in the joint.

A growing number of studies have documented decreased muscular performance after stretching. As with other forms of training, stretching temporary weakens the body, prior to the body recovery and it counteracting those effects. Researchers conducting maximum strength tests, running and jumping studies have observed muscle performance reductions of 4-30%. The cause appears to be neuromuscular inhibition (reduced ability to activate the muscle and speed of nerve impulse) and decreased muscle contraction force. Fowles and colleagues [2] observed this to last up to an hour. A recent article by Groner [3] states this could be up to 24 hours.

Another important point to remember is that flexibility is not an overall body characteristic, but is dependant on the specific joint and direction of motion. A person can have normal static flexibility in one part of their body and be inflexible or hypermobile in another. Gender (women typically have more static flexibility than men) and body shape and size affect static flexibility. People can lose static flexibility due to lack of physical activity, or from work or sport related repetitive motions as in the overarm motions in baseball throwing and some tennis strokes. Continual usage of high heels may cause a decrease in ankle flexibility.

While data is available on normal ranges of motion for most joints, it is not known whether there is an "optimal" level of static flexibility for different joints or the entire body. More research is needed to determine this and correlate it with injury reduction.

Using newer methods of measuring flexibility, scientists record "dynamic flexibility" or muscle stiffness, which refers to how quickly the tissue resistance rises in a stretch. Knudson has noted the following, "... stretching does not create a short-term decrease muscle stiffness" and "... several studies have also shown that stretch training over time does not decrease muscle stiffness." While you may feel lower passive tension in the a particular muscle group/joint, this is not an indicator of the mechanical stiffness of a tissue.

However, there are benefits to stretching as pointed out and experts are suggesting that stretching usually or normally be done in your cool-down phase and avoided in warm-up for athletic competition. Knudson [1] notes, "Stretches should slowly elongate and hold muscles with low levels of force for 15 to 30 seconds. Four to five stretches per muscle group or area of the body are usually recommended." Only individuals who need great amounts of flexibility, like gymnasts and dancers, or have severe flexibility limitations would engage in stretching at the end of a warm-up.

Quoting Knudson, "Given that the lowest injury rates seem to correspond to normal flexibility and higher injury rates with the extremes in flexibility (inflexible and hypermobile), maintenance of normal or moderate amounts of static flexibility should be the goal for most people. ... Most athletes with normal flexibility should perform their stretching routines after practice or competition."

Many thanks to Dr. Duane Knudson for his assistance with this column.

Until Next Month ... Jani

Green DotGreen DotGreen Dot

Tennis SET Archive

If you have not already signed up to receive our free e-mail newsletter Tennis Server INTERACTIVE, you can sign up here. You will receive notification each month of changes at the Tennis Server and news of new columns posted on our site.

This column is copyrighted by Jani Macari Pallis, Ph.D., all rights reserved.

Dr. Jani Macari Pallis is the founder and CEO of Cislunar Aerospace, Inc., an engineering and research firm in San Francisco. In addition to her engineering practice, she has led two collaborations between NASA and Cislunar, creating educational materials on the aerodynamics of sports for pre-college students and educators. As the head of NASA's "Aerodynamics in Sports" project, she has led a team of researchers investigating the aerodynamics, physics and biomechanics of tennis. The group has conducted high speed video data capture at the US Open and research of ball/court interaction, footwork, serve speeds, trajectories and ball aerodynamics. Pallis received a BS and MS from the Georgia Institute of Technology, an MS in mechanical engineering from the University of California, Berkeley and a Ph.D. in mechanical and aeronautical engineering from the University of California, Davis. She is a member of the Executive Committee of The International Sports Engineering Association.

Questions and comments about these columns can be directed to Jani by using this form.


Web tennisserver.com
nodot nodot
The Tennis Server
Ticket Exchange

Your Source for tickets to professional tennis & golf events.
Australian Open Tickets
Dallas Open Tickets
Delray Beach Open Tickets
ATX Open Tickets
Mexican Open Tickets
BNP Paribas Open Tickets
Miami Open Tickets
Credit One Charleston Open Tickets
US Men's Clay Court Championships Tickets
Wimbledon Tickets
Citi Open Tennis Tournament Tickets
Mubadala Silicon Valley Classic Tickets
National Bank Open Womens Tennis Canada Tickets
Odlum Brown Van Open r Tickets
Tennis In The Land Tickets
US Open Tennis Championship Tickets
Laver Cup Vancouver Tickets


Popular Tennis books:
Winning Ugly: Mental Warfare in Tennis-Lessons from a Master by Brad Gilbert, Steve Jamison
The Best Tennis of Your Life: 50 Mental Strategies for Fearless Performance by Jeff Greenwald
The Inner Game of Tennis by W. Timothy Gallwey
Most Recent Articles:
October 2022 Tennis Anyone: Patterns in Doubles by John Mills.
September 2022 Tennis Anyone: Short Court by John Mills.




"Tennis Server" is a registered trademark and "Tennis Server INTERACTIVE" is a trademark of Tennis Server. All original material and graphics on the Tennis Server are copyrighted 1994 - by Tennis Server and its sponsors and contributors. Please do not reproduce without permission.

The Tennis Server receives a commission on all items sold through links to Amazon.com.


Tennis Server
Cliff Kurtzman
791 Price Street #144
Pismo Beach, CA 93449
Phone: (281) 480-6300
Online Contact Form
How to support Tennis Server as a Sponsor/Advertiser
Tennis Server Privacy Policy