Things are a bit slow tonight, and we’ve got a bunch of coaches on at once, so I figured I’d toss a little bit of academia your way.
[quote]Leetun DT, Ireland ML, Willson JD, Ballantyne BT, Davis IM. Core stability measures as risk factors for lower extremity injury in athletes. Med Sci Sports Exerc. 2004 Jun;36(6):926-34.
INTRODUCTION/PURPOSE: Decreased lumbo-pelvic (or core) stability has been suggested to contribute to the etiology of lower extremity injuries, particularly in females. This prospective study compares core stability measures between genders and between athletes who reported an injury during their season versus those who did not. Finally, we looked for one or a combination of these strength measures that could be used to identify athletes at risk for lower extremity injury. METHODS: Before their season, 80 female (mean age = 19.1 +/- 1.37 yr, mean weight 65.1 +/- 10.0 kg) and 60 male (mean age = 19.0 +/- 0.90 yr, mean weight 78.8 +/- 13.3 kg) intercollegiate basketball and track athletes were studied. Hip abduction and external rotation strength, abdominal muscle function, and back extensor and quadratus lumborum endurance was tested for each athlete. RESULTS: Males produced greater hip abduction (males = 32.6 +/- 7.3%BW, females = 29.2 +/- 6.1%BW), hip external rotation (males = 21.6 +/- 4.3%BW, females = 18.4 +/- 4.1%BW), and quadratus lumborum measures (males = 84.3 +/- 32.5 s, females = 58.9 +/- 26.0 s). Athletes who did not sustain an injury were significantly stronger in hip abduction (males = 31.6 +/- 7.1%BW, females = 28.6 +/- 5.5%BW) and external rotation (males = 20.6 +/- 4.2%BW, females = 17.9 +/- 4.4%BW). Logistic regression analysis revealed that hip external rotation strength was the only useful predictor of injury status (OR = 0.86, 95% CI = 0.77, 0.097). CONCLUSION: Core stability has an important role in injury prevention. Future study may reveal that differences in postural stability partially explain the gender bias among female athletes.[/quote]
Well, well, well. What do you know? Weak glutes (hip external rotators and abductors) are a risk factor for injury. Where have you heard that before? 
Well, duh…
[quote]Goto K, Ishii N, Kizuka T, Takamatsu K.
The impact of metabolic stress on hormonal responses and muscular adaptations.Med Sci Sports Exerc. 2005 Jun;37(6):955-63.
PURPOSE:: The purpose of this study was to examine the impact of exercise-induced metabolic stress on hormonal responses and chronic muscular adaptations. METHODS:: We compared the acute and long-term effects of an “NR regimen” (no-rest regimen) and those of a “WR regimen” (regimen with rest period within a set). Twenty-six male subjects were assigned to either the NR (N = 9), WR (N = 9), or control (CON, N = 8) groups. The NR regimen consisted of 3-5 sets of 10 repetitions at 10-repetition maximum (RM) with an interset rest period of 1 min (lat pulldown, shoulder press, and bilateral knee extension). In the WR regimen, subjects completed the same protocol as the NR regimen, but took a 30-s rest period at the midpoint of each set of exercises in order to reduce exercise-induced metabolic stress. Acute hormonal responses to both regimens were measured followed by a 12-wk period of resistance training. RESULTS:: Measurements of blood lactate and serum hormone concentrations after the NR and WR regimens showed that the NR regimen induced strong lactate, growth hormone (GH), epinephrine (E), and norepinephrine (NE) responses, whereas the WR regimen did not. Both regimens failed to cause significant changes in testosterone. After 12 wk of resistance training, the NR regimen caused greater increases in 1RM (P < 0.01), maximal isometric strength (P < 0.05), and muscular endurance (P < 0.05) with knee extension than the WR regimen. The NR group showed a marked increase (P < 0.01) in muscle cross-sectional area, whereas the WR and CON groups did not. CONCLUSION:: These results suggest that exercise-induced metabolic stress is associated with acute GH, E, and NE responses and chronic muscular adaptations following resistance training.[/quote]
If you take a 30-second break in the middle of each set, you’ll never achieve full MU recruitment and, in turn, sufficient tension or hypoxia to stimulate hypertrophy. Why anyone would take the time to do this study is beyond me.
Eric,
I seem to get a sharp pain on the front part of my shoulder when I do pull ups.
I am currently following NNM to fix some imbalances.
Do you feel that this program addresses my issue? Do you have any contraindications?
EC-anything academic on the leg extension?I’m having an argument with a guy at work( a post rehab training center) That leg extensions are crap for healthy and unhealthy people.The problem is I can’t find any scienetifc articles saying that they hurt the knee but I have read about them adding alot of force on the patella. Whats your thoughts on this issue?
Would you know of any quick links online to any journals?
Eric,
I’ve been thinking about getting into powerlifting, but I first decided to address all of the joint issues and imbalances I seem to have.
Anyways, what type of routine do you recommend to get me started. The more specific you get, the better.
As far as modifying the program is concerned, do the following:
Do your cable woodchops from hip height (not high to low).
In place of the decline close grip bench, do neutral grip decline DB press on a 6010 tempo.
Replace Saxon side bends with regular ol’ DB side bends.
[quote]StrikeT wrote:
Eric,
I seem to get a sharp pain on the front part of my shoulder when I do pull ups.
I am currently following NNM to fix some imbalances.
Do you feel that this program addresses my issue? Do you have any contraindications?
[/quote]
Man, I had a great handout from an old class on patellofemoral joint forces in open and closed chain knee extension. I wish I could remember what I did with it. I’ll have to see if I can dig up a study for you.
[quote]bigpump23 wrote:
EC-anything academic on the leg extension?I’m having an argument with a guy at work( a post rehab training center) That leg extensions are crap for healthy and unhealthy people.The problem is I can’t find any scienetifc articles saying that they hurt the knee but I have read about them adding alot of force on the patella. Whats your thoughts on this issue?
Would you know of any quick links online to any journals?[/quote]
FYI, lateral patellar tracking is a bad thing; leg extensions tend to promote it more than closed-chain knee extension (squatting variations).
[quote]Powers CM, Ward SR, Fredericson M, Guillet M, Shellock FG. Patellofemoral kinematics during weight-bearing and non-weight-bearing knee extension in persons with lateral subluxation of the patella: a preliminary study. J Orthop Sports Phys Ther. 2003 Nov;33(11):677-85.
STUDY DESIGN: Single-group, repeated-measures design. OBJECTIVE: To compare patellofemoral joint kinematics during weight-bearing and non-weight-bearing knee extension in persons with lateral subluxation of the patella. BACKGROUND: The only previous study to quantify differences in patellofemoral joint kinematics during weight-bearing and non-weight-bearing tasks was limited in that static loading conditions were utilized. Differences in patellofemoral joint kinematics between weight-bearing and non-weight-bearing conditions have not been quantified during dynamic movement. METHODS AND MEASURES: Six females with a diagnosis of patellofemoral pain and lateral subluxation of the patella participated. Using kinematic magnetic resonance imaging, axial images of the patellofemoral joint were obtained as subjects extended their knee from 45 degrees to 0 degrees during non-weight-bearing (5% body weight resistance) and weight-bearing (unilateral squat) conditions. Measurements of patellofemoral joint relationships (medial/lateral patellar displacement and patellar tilt), as well as femur and patella rotations relative to an external reference system (ie, the image field of view), were obtained at 3 degrees increments during knee extension. RESULTS: During non-weight-bearing knee extension, lateral patellar displacement was more pronounced than during the weight-bearing condition between 30 degrees and 12 degrees of knee extension, with statistical significance being reached at 27 degrees, 24 degrees, and 21 degrees. No differences in lateral patellar tilt were observed between conditions (P = .065). During the weight-bearing condition, internal femoral rotation was significantly greater than during the non-weight-bearing condition as the knee extended from 18 degrees to 0 degrees. During the non-weight-bearing condition, the amount of lateral patellar rotation was significantly greater than during the weight-bearing condition throughout the range of motion tested. CONCLUSIONS: The results of this study demonstrated that lateral patellar displacement was more pronounced during non-weight-bearing knee extension compared to weight-bearing knee extension in persons with lateral patellar subluxation. In addition, the results of this investigation suggest that the patellofemoral joint kinematics during non-weight-bearing could be characterized as the patella rotating on the femur, while the patellofemoral joint kinematics during the weight-bearing condition could be characterized as the femur rotating underneath the patella.[/quote]
Another nail in the coffin. There goes any hope of functional carryover.
[quote]Stensdotter AK, Hodges PW, Mellor R, Sundelin G, Hager-Ross C. Quadriceps activation in closed and in open kinetic chain exercise. Med Sci Sports Exerc. 2003 Dec;35(12):2043-7.
PURPOSE: For treatment of various knee disorders, muscles are trained in open or closed kinetic chain tasks. Coordination between the heads of the quadriceps muscle is important for stability and optimal joint loading for both the tibiofemoral and the patellofemoral joint. The aim of this study was to examine whether the quadriceps femoris muscles are activated differently in open versus closed kinetic chain tasks. METHODS: Ten healthy men and women (mean age 28.5 +/- 0.7) extended the knees isometrically in open and closed kinetic chain tasks in a reaction time paradigm using moderate force. Surface electromyography (EMG) recordings were made from four different parts of the quadriceps muscle. The onset and amplitude of EMG and force data were measured. RESULTS: In closed chain knee extension, the onset of EMG activity of the four different muscle portions of the quadriceps was more simultaneous than in the open chain. In open chain, rectus femoris (RF) had the earliest EMG onset while vastus medialis obliquus was activated last (7 +/- 13 ms after RF EMG onset) and with smaller amplitude (40 +/- 30% of maximal voluntary contraction (MVC)) than in closed chain (46 +/- 43% MVC). CONCLUSIONS: Exercise in closed kinetic chain promotes more balanced initial quadriceps activation than does exercise in open kinetic chain. This may be of importance in designing training programs aimed toward control of the patellofemoral joint.[/quote]
Wilk (Birmingham, AL) is one of the most respected sports medicine physicians/surgeons in the country.
[quote]
Escamilla RF, Fleisig GS, Zheng N, Barrentine SW, Wilk KE, Andrews JR. Biomechanics of the knee during closed kinetic chain and open kinetic chain exercises. Med Sci Sports Exerc. 1998 Apr;30(4):556-69.
PURPOSE: Although closed (CKCE) and open (OKCE) kinetic chain exercises are used in athletic training and clinical environments, few studies have compared knee joint biomechanics while these exercises are performed dynamically. The purpose of this study was to quantify knee forces and muscle activity in CKCE (squat and leg press) and OKCE (knee extension). METHODS: Ten male subjects performed three repetitions of each exercise at their 12-repetition maximum. Kinematic, kinetic, and electromyographic data were calculated using video cameras (60 Hz), force transducers (960 Hz), and EMG (960 Hz). Mathematical muscle modeling and optimization techniques were employed to estimate internal muscle forces. RESULTS: Overall, the squat generated approximately twice as much hamstring activity as the leg press and knee extensions. Quadriceps muscle activity was greatest in CKCE when the knee was near full flexion and in OKCE when the knee was near full extension. OKCE produced more rectus femoris activity while CKCE produced more vasti muscle activity. Tibiofemoral compressive force was greatest in CKCE near full flexion and in OKCE near full extension. Peak tension in the posterior cruciate ligament was approximately twice as great in CKCE, and increased with knee flexion. Tension in the anterior cruciate ligament was present only in OKCE, and occurred near full extension. Patellofemoral compressive force was greatest in CKCE near full flexion and in the mid-range of the knee extending phase in OKCE. CONCLUSION: An understanding of these results can help in choosing appropriate exercises for rehabilitation and training.[/quote]
It’s like taking candy from a baby:
[quote]
Stiene HA, Brosky T, Reinking MF, Nyland J, Mason MB. A comparison of closed kinetic chain and isokinetic joint isolation exercise in patients with patellofemoral dysfunction. J Orthop Sports Phys Ther. 1996 Sep;24(3):136-41.
Recently, there has been attention to the clinical application of closed kinetic chain and joint isolation exercise. Our purpose was to compare the effect of joint isolation and closed kinetic chain exercise on quadriceps muscle performance and perceived function in patients with patellofemoral pain. Twenty-three patients participated in an 8-week training period and were assigned to either a closed kinetic chain or a joint isolation exercise training group. An 8-inch (20.3 cm) retro step-up test was performed at baseline, 8 weeks, and 1 year. Seated knee extension testing was measured at baseline and at 8 weeks using peak concentric torque on an isokinetic dynamometer at 90 degrees/sec, 180 degrees/sec, and 360 degrees/sec. Perceived functional status was rated as excellent, good, fair, or poor based on questionnaire response. Statistical analysis showed that both groups had significant improvement in peak torque at all speeds, but only the closed kinetic chain group showed significant improvement in closed kinetic chain testing and perceived functional status. We concluded that closed kinetic chain training may be more effective than joint isolation exercise in restoring function in patients with patellofemoral dysfunction.[/quote]
Here’s the one I wanted!
[quote]
Steinkamp LA, Dillingham MF, Markel MD, Hill JA, Kaufman KR. Biomechanical considerations in patellofemoral joint rehabilitation. Am J Sports Med. 1993 May-Jun;21(3):438-44.
Patellofemoral joint biomechanics during leg press and leg extension exercises were compared in 20 normal subjects (10 men, 10 women) aged 18 to 45 years. Knee moment, patellofemoral joint reaction force, and patellofemoral joint stress were calculated for each subject at four knee flexion angles (0 degree, 30 degrees, 60 degrees, and 90 degrees) during leg press and leg extension exercises. All three parameters (knee moment, patellofemoral joint reaction force, and patellofemoral joint stress) were significantly greater in leg extension exercise than leg press exercise at 0 degree and 30 degrees of knee flexion (P < 0.001). At 60 degrees and 90 degrees of knee flexion, all three parameters were significantly greater in leg press exercise than leg extension exercise (P < 0.001). Patellofemoral joint stresses for leg press and leg extension exercises intersected at 48 degrees of knee flexion. This study demonstrates that patients with patellofemoral joint arthritis may tolerate rehabilitation with leg press exercise better than with leg extension exercise in functional ranges of motion because of lower patellofemoral joint stresses.[/quote]
Wow, that’s a loaded question. I’d need to know your strengths and weaknesses in order to point you in the right direction. Dave Tate’s beginner program isn’t a bad start, although you’ll need to be careful jumping right into it if you’ve got some existing joint problems. You might need to modify it to do more prehab for the areas that are giving you trouble.
[quote]StrikeT wrote:
Eric,
I’ve been thinking about getting into powerlifting, but I first decided to address all of the joint issues and imbalances I seem to have.
Anyways, what type of routine do you recommend to get me started. The more specific you get, the better.[/quote]
Eric,
I’m always trying to learn, so here goes: Why would I switch Saxon Side Bends to regular db side bends?
Eric,
Do you have any links to the way that you structure your own training?
I would like to see what you do just for kicks.
Eric,
How did you decide that it was time to get your life into gear and start following your passion? Was it a gradual process or were you just born with it?
If the anterior shoulder pain is most prominent with chin-ups, you’d be wise to avoid overhead activity for a bit. This is especially true of approximation exercises (movements that push the humeral head into the socket).
[quote]StrikeT wrote:
Eric,
I’m always trying to learn, so here goes: Why would I switch Saxon Side Bends to regular db side bends?[/quote]
Just wait until August; I’ll be putting together something based on my current 12-week training cycle. I wouldn’t recommend that people follow my program; I’d rather use it as an educational piece regarding how you can plan your training. You need to be able to justify everything that you do.
TC has another piece of mine that details how I track volume and intensity in my programming. It may seem complex to some, but I’m a type A when it comes to my training, so I appreciate the organization. Plus, my results have been great since I started with this charting, so I’ve stayed the course.
[quote]StrikeT wrote:
Eric,
Do you have any links to the way that you structure your own training?
I would like to see what you do just for kicks.[/quote]
A little bit of both. I got pretty sick my senior year of high school and lost a lot of weight the wrong way. In gaining it back, I fell in love with lifting and proper diet. If you had asked me in high school, I never would have said that I would be in this line of work. I always loved athletics, but I absolutely HATED science. I figured that I would just become an accountant like everyone else in my family.
Anyway, two years into business school I realized that I was more interested in training and reading about it than I was passionate about starting at the ticker all day to see what the Dow and NASDAQ were doing! I was growing like a weed, getting stronger, and feeling a lot better about myself; it was just a logical next step to do what I loved for a living. That was the Spring of 2001, and it’s been smooth sailing ever since.
[quote]StrikeT wrote:
Eric,
How did you decide that it was time to get your life into gear and start following your passion? Was it a gradual process or were you just born with it?
[/quote]
Eric,
My buddy suffers pain in his elbows when he does skull crushers. He also feels a slight discomfort when he benches big numbers. Any thoughts?