are you doing the isometrics a la Jay Schroeder's extreme isometrics? There was a whole extended thread here about those a while back. Even if that's not where you got the idea, how are they treating you?
I played around with isometrics since my elbows get often lateral tendonitis from bending them repetitive under load since 7 years (I’m 40 years old). I did a lot of overcoming isometrics in mid position to muscular failure (1 set, 60-90 seconds, ramping up the intensity every 20-30 seconds). I also did a lot of BW static (yielding) holds in mid position. I felt good, but a little stiff (like a board with joints(?)). I incoorperated OS and crawling since 3 years into my training template, but I got no mobility benefits. During crawling my anterior chain/pressing chain were flexed, so my chest, front delts , triceps and especially my hip flexors got stronger but seemed to shorten. Since I incooperated the static holds in the stretched position, my flexibility, stability, strength over the full range of motion seems to profit, my joints feel better. My recovery time is better too, can do my training (primarily OS and static holds) almost daily with higher intensity, but feeling fresh and ready 30 minutes afterwards. But even with poor / low protein diet I make progress this way, I feel surprisingly fit. But this is just my experience, everybody has to find his own way.
If someone wants to read / see / hear something about extreme Isometrics or quasi Eccentric isometrics I recommend to have a look at:
www.just-fly-sports.com
www.just-fly-sports.com
Why the Extreme ISO Lunge Should Be in Your Training Arsenal
Implementing Extreme Isometrics By: Rob Assise I have written about my personal experience with extreme isometrics in the past (here and here). I also conducted a webinar where I discussed the numerous whys behind the method as well as what I feel are the best ways to teach the extreme isometric
www.re-evolutionathletics.com
Erfahrungsbericht ISO Extrem Hold Training nach Jay Schroeder (In German)
Coach Christian Thibaudeau, 4 parts:
Dr. Mark Wetzel: Unpacking Extreme Isometrics, Super Slow Training and Effective CNS Training - Just Fly Sports (he made 3 other podcasts about extreme Isometrics)
Peter Tzemis „Anabolic Streching 2.0“ .He discribes Exercises with weights, but also different training principles for different benefits, which could be adapted to BW variations.
Slow motion BW Isometrics:
A rep is not a rep. Especially when you stretch it out 30 times longer than how it's normally done. Sounds crazy, but so are the gains you'll get from it. Check it out.
www.t-nation.com
Pavels slow twich articles on this board
Drew Baye „Poject Kratos“ (BW HIT)
(this guy made a good video with Steve Maxwell, and some other with isometrics, crawling, breathing and superslow BW workouts, with minimal equipment.
John Little „Time Savers Workout“ (an abbreviated approach, BW, weights, or machines. Three exercises, one set, one rep, once a week, high intensity)
Ellington Darden „30-30-30“ (One rep: 30sec negative, 30 sec positive, 30 sec negative, 8 main exercises, BW, weights or machines)
Steve Maxwell „2 minutes 1 rep“
Overcoming Isometrics:
Matt Schifferle „Overcoming Isometrics“
Drew Baye „Timed Static Contractions“ (HIT with a strap)
Steve Maxwell „Overcoming Isometrics“
Dragondoor „Isometrics Manual“
Other:
Steve Maxwell „ Yielding Isometrics“
…ups this post got longer than I thought, I will stop here. Have a good day.