Most coaches use a battery of tests to evaluate the status of their athletes and determine areas of strength and weakness. Tests such as the vertical jump, broad jump, pro agility shuttle and 40-yard dash are often used when testing athletes in a variety of sports. While many coaches are content with the quantitative number (how high did they jump, how fast did they run, etc.) derived from the test results, a qualitative evaluation of the results (how effectively did they absorb force, how (more…)
Post-workout meals and snacks are essential if you’re working out every day. Make sure to eat something as soon as possible after workouts, because your snacks and meals provide the nutrients needed for muscle rebuilding and recovery. The sooner you start the building and recovery process the better.
The following exercise was recommended by Vern Gambetta. I have used it with good success, first with the Mets and currently with the Rangers. This exercise has three movement sequences that emphasize the loading and unloading of the hips and hamstrings in the sagittal, frontal and transverse plane. It can be used as both a conditioning and rehabilitation exercise.
Lunge and Reach to Floor. Emphasis: Stand erect with a DB in each hand. Set the abs, step (lunge) forward on the left leg and reach forward with both hands until the DBs lightly touch the floor. Pause for 2-3 seconds and then push back to the starting position with the lead leg. Perform the assigned number of reps on the left leg and then repeat on the opposite leg. For variety and more balance and coordination, alternate right and left legs and do 10 reps on each side. Keep the abs tight throughout the exercise. As you reach to the floor the hamstrings are loaded at both the origin and insertion. This is functionally similar to the load placed on the hamstrings during running at foot contact. When you touch the floor, push off the ground explosively with the lead leg. This is similar to the load from foot contact to the push off phase. Keep the neck and head in a straight line with the trunk throughout the exercise. Benefits: Eccentric loading of the hamstrings.
Lunge and Reach Overhead. Emphasis: This exercise emphasizes the loading and unloading of the hip flexors and adductors in the sagittal plane. In this exercise both the hip flexors and adductor group are lengthened. This load is necessary to effectively unload the hip creating an explosive knee drive during running. Stand erect with feet shoulder-width apart, arms extended and hands overhead with palms facing forward. Set the abs and lunge forward on the left leg until the back knee almost touches the ground. Push back with the lead leg and return to the starting position. Perform the assigned number of reps on the left leg and then repeat on the opposite leg. For variety and more balance and coordination, alternate right and left legs and do 10 reps on each side. Keep the abs tight, arms extended and hands overhead from start to finish. Do not arch the back. Perform the exercise with a MD Ball, DBs or kettle bells to increase the intensity of the movement. Benefits: Eccentric loading of the hip flexor and adductor group and increased range of motion in shoulders and T-Spine.
Lunge and Twist. Emphasis: This exercise emphasizes the loading and unloading of both the hip flexors, adductors and abdominals in the transverse plane. Most baseball movements occur in the transverse plane, making this exercise very appropriate. Stand erect with arms extended and hands together in front of the body at chest height. Keep the palms together, set the abs and lunge forward on the left leg until the back knee almost touches the ground. As the back knee approaches the ground, twist the trunk, arms and hands toward the lead leg. Pause for 1-2 seconds, twist back until the arms are directly in front of the body and then push back with the lead leg to return to the starting position. Perform the assigned number of reps on the left leg and then repeat on the opposite leg. For variety and more balance and coordination, alternate right and left legs and do 10 reps on each side.
Keep the abs tight, arms extended and palms together throughout the exercise. Perform the exercise with a MD Ball, DBs or kettle bells to increase the intensity of the movement. To increase range of motion, balance and coordination, bring both hands up and over the shoulder on the side of the lead leg. Benefits: Transverse training of the hip flexors, adductors, core and T-spine.
Jose Vazquez, PT, CSCS
Head Strength Coach, Texas Rangers
The sliding leg curl is a good, closed chain, hip dominant exercise that simultaneously works the muscles involved in knee flexion and hip extension, increases strength and improves coordination among the muscles of the posterior chain. This is a complex and extremely functional exercise when performed correctly in that it uses the glutes to stabilize the pelvis while the hamstrings work to assist with pelvic stabilization and control flexion and extension at the knee.
Sliding leg curls can be performed using either a slideboard or Valslide discs. Since slideboards are hard to pack and seldom available on the road, we prefer to use portable Valslide discs because they enable us to perform the exercise in the same manner both at home and on the road.
The starting position is a supine, bridged position with the feet and knees together; ankles dorsiflexed, heels on the Valslides and legs extended until the buttocks almost touch the ground. Next, set the abs, squeeze the glutes and perform a leg curl without flexing at the hips. Pause at the top, return to start and repeat. Keep the hips up throughout the exercise. Don’t let the butt sag as this takes glutes out of the exercise and severely diminishes the effectiveness of the exercise. Don’t extend the lumbar spine. Proper execution requires hip extension, not lumbar extension. The hip and hamstring actions in this exercise mimic those used in running, i.e., the glutes act as hip extensors while the hamstrings act as both synergists for hip extension and knee flexion.
When you can perform 2-3 sets of 6-8 reps with perfect form, progress to single-leg curls and then resisted double- and single-leg curls. To perform double-leg resisted curls, put a small plate on top of each Valslide and repeat the exercise. Start slow, adding as little as 5 pounds can significantly increase in the intensity of the exercise.
Note: some athletes, especially those with glute-firing issues, will not be able to switch from the eccentric to the concentric movement while maintaining glute contraction. In this case, the hips will drop and flex during the concentric movement. If this happens, perform eccentric only movements with a 5-second count down until strength and function are improved. Start with toes up and heels on the Valslides in double-leg bridge. Set the abs, squeeze the glutes and slowly slide out from the hip-flexed bridge position until the legs are out stretched. Relax, walk the feet back to the bridge position and repeat for 3-5 reps.
Brian Jordan, RSCC*D, is the Head Strength and Conditioning Coach for the Colorado Rockies.
During the off-season, I try different activities and think about how I might be able to use a few of these new exercises and drills with my players. Two years ago, I attended a “barre class” that used non-impact, small movement exercises to isolate individual muscle groups. One muscle group that these exercises had the most impact on was my glutes. After doing some of the exercises, I walked out of class feeling like I had just done 1,000 squats and lunges. Although the classes were predominantly filled with women trying to “firm and tone” their bodies (especially their backsides), I found that these exercises were great for activating the glutes before a lower body workout and/or when the glutes are inhibited. Since many of the exercises are performed while standing, they offer a unique alternative to those typically performed while lying on the ground. The following are five exercises that I have had success with. Do 1-2 sets of 15-20 reps on each leg. Start with one set and gradually build to 2 sets of each with perfect form. Do one set of the standing figure 4 stretch between each set of exercises and hold each stretch for 20-30 seconds.
Straight Leg Raise
Set-Up. Stand facing a bar with feet shoulder-width apart and toes pointing forward. Place both hands on the bar with arms fully extended and bend forward at the waist until the back is flat. Retract the scapula, set the core, square up the hips and slightly bend both the support and non-support leg at the knee. This is your starting position.
Movement. Extend the non-support leg until it is parallel to the ground, point the toes (plantar flex the foot) and raise and lower the leg from the hip about two inches at a time in a “pulsing” movement for 15-20 reps and then switch legs.
20 Degrees Out and Raise
Set-Up. Same as the previous exercise.
Movement. Start by extending the non-support leg until it is parallel to the ground with the toes pointed (plantar flexed). Abduct the non-support leg 20 degrees (move leg away from hip), raise and lower the leg about 2 inches and return to the midline. This is one rep. Do 15-20 reps and switch legs.
Open Hip Leg Raise
Set-Up. Same as the previous exercise
Movement. Extend the non-support leg until it is parallel to the ground, point the toes, rotate the non-support leg outward about 90 degrees (open the hip) and raise and lower the leg from the hip about 2 inches at a time. Keep the non-support leg parallel to the ground and return the leg to the midline after each rep. Do 15-20 reps and switch legs.
Movement. Keeping a slight bend in the support leg, point the toes of the non-support leg, abduct the leg about 200 out away from the hip and extend the non-support leg backwards about 2 inches. Return to start and repeat in a pulsing movement for 15-20 reps. Switch legs and repeat.
Set-Up.Stand arms’- length away and facing the bar with feet shoulder-width apart and toes facing forward. Grab the bar with both hands and place the ankle of one leg just above the knee of the opposite leg. This is your starting position.
Movement. Keeping the trunk erect, set the core, drop the hip of the non-support leg until both hips are level and then bend the knee of the non-support leg to stretch the glutes on that side of the body. Hold for 20-30 seconds, return to start and repeat on the opposite leg..
Ed W. Yong, MS, CSCS
Spokane Indians – Texas Rangers
The most important thing to remember about getting faster is: “In order to improve speed, you must run fast in training.” So, running up and down a track or field at 60-70% of max effort will not make you a faster runner. Research indicates that you must run at 95-100% of max speed to increase sprinting speed. In effect, you need to train your brain to activate and recruit your fast-twitch muscle fibers to move your body quickly. The more muscle fibers you ‘teach’ your brain to recruit, the faster you will be able to accelerate. But in order to train at high intensity, you must be fresh and well rested before each workout and between every rep. Some key tips to remember when planning and implementing sprint workouts are presented below:
• Train for the right kind of speed. Most team sports are games of acceleration, starting, stopping and change directions. Train to run fast in game situations. Limit your runs to short distances (5 to 30m) and work on improving your ability to start, stop and change directions.
• Emphasize “quality” for each sprint. Run at 95-100% of max for the entire distance. If you are running at less than 95% of max, you are working on something other than speed. If you don’t run fast, you won’t get faster.
• Don’t jog. If you spend 80% of your time jogging, you are spending 80% of your time practicing to be slow.
• Observe adequate rest and recovery between workouts and sprints. Don’t rush through workouts. Rest at least 90 sec between sprints. Allow adequate time for rest and recovery between workouts. It takes 48 hr for your central nervous system to recover from high intensity sprint training. Don’t do sprint workouts on consecutive days.
• Race against or chase your teammates during sprint drills to motivate yourself to run faster. Competition helps ensure that you give 100% effort.
• Time your runs. You must know how fast you are running to ensure that you are giving enough effort to stimulate improvement.
• Limit the volume of sprint work during workouts. The total volume for sprint workouts should not exceed 300m for team sports athletes (e.g., 10x30m or 3x5x20m). When team sports athletes exceed this volume the neuromuscular system becomes extremely fatigued, the body can’t consistently produce 100% effort, technique breaks down and the risk of injury increases.
Derek Hansen works with athletes in all sports, including the Canadian National Team. To read more from Derek, go to http://www.strengthpowerspeed.com/
In the words Yogi Berra, “you can see a lot by watching”. Over the years, I have learned a lot by talking with and watching opposing strength and conditioning coaches as they put their teams through pre- and post-game warm-ups and workouts. The following is a good, multi-plane, multi-joint, total body, warm-up exercise that is used by Dong Lien (CSCS, RSCC), strength and conditioning coordinator for the Philadelphia Phillies. It’s a dynamic exercise that targets most of the muscles in the upper and lower body, engages the core, challenges balance and engages the muscles used when running. It can be used as an essential part of a pre-practice / pre-game warm-up routine and/or to prepare for running drills.
Stand with your feet shoulder-width apart with both arms extended down the sides. Set the core, squeeze the glutes and then step forward with your left leg into a lunge position until your left thigh is parallel to the ground and your right knee is almost touching the ground. As you descend into the lunge position, extend the left arm straight down and the right arm out and up toward the sky. From this low lunge position with one arm up and the other arm down, slowly rotate your torso and right shoulder up and over your lead (left hip). Both arms should form a straight line. Hold this position for 2-3 seconds. Push back with the lead (left) leg to return to a standing, split-squat position with both arms down the sides. Step forward with the opposite leg and repeat the sequence. Continue alternating legs until you have performed 5-6 reps on each leg.
If you have trouble with balance or lack adequate walking space, perform the exercise in-place repeating the movement sequence 5-6 times on one leg before working the opposite leg. For added range of motion, twist the trunk toward the lead leg as you reach overhead. To increase balance, perform the drill while lunging backwards.
Gene Coleman was the Head S&C Coach for the Houston Astros from 1978-2012 and is currently a strength and conditioning consultant for the Texas Rangers and Professor in the Fitness and Human Performance Program at the University of Houston – Clear Lake.
Track and field coaches divide sprint training into three components; acceleration, maximum velocity, and speed endurance. Acceleration is the process of increasing your velocity. Maximum velocity is running all out. Speed endurance is your ability to maintain your maximum velocity. For a sprinter, all three are important. For a jumper, they may just focus their training on the first two.
For non-track and field athletes, this is a little more difficult of a concept. A world-class sprinter may take 60-80 meters to reach maximum velocity. The truth is that the faster someone can sprint, the longer it takes them to reach maximum velocity. The distinction between acceleration and maximum velocity sounds like splitting hairs, but it’s actually important because sprinting technique is a little different between the two.
During pure acceleration, the first few steps, the athlete is low to the ground. They are focusing heavily on front-side mechanics while sprinting (i.e. knee up, toe up, pushing the body as they sprint). As their velocity increases, they become more upright and as that happens they begin to focus on backside mechanics as well (bring the heel to the hip, drive the foot down towards the ground using the hip muscles). Their sprinting focuses on pushing and pulling the body along.
Outside of track and field, rarely do athletes get to run in a perfectly straight line for 60 to 80 meters. Athletes have to take a few steps, change directions, react to situations, and factor the ball into the equation. This has led to the thought that athletes don’t need to perform maximum velocity work in their speed training.
The challenge here is that maximum velocity is the goal whether the athlete takes three steps or runs for 100 meters, in other words this is where the athlete is attempting to get to. The other challenge is that after 5-10 meters, the athlete will be running upright and will be using both front side and backside mechanics even though they aren’t at maximum velocity yet.
What this means is that by failing to focus on some maximum velocity training, we may not be preparing our athletes for outliers during the game (i.e. there are times when people make mistakes and the athlete gets to run flat out for 40 meters) and we are not preparing our athletes to be running with proper technique. All of this combined can limit performance and increase the odds of injuries.
With training time being limited, there are a number of tools that can be used to help focus on this without devoting an exhausting amount of time to it. These include:
• Sprinting technique drills: Technique drills are done at slower speed than sprinting and break the motion down into its components. These can be used as warm-up, mobility work, and to reinforce proper technique. Note that these are not a substitute for sprinting, but when combined with the other tools can be very effective at reinforcing good habits.
• 40-60 meter sprints: The best way to train athletes to run at maximum velocity is to have them do it. Sprints at this distance require a serious warm-up, must be done at 100%, require full recovery, and the coach must consistently focus on good technique. Performing a thorough warm-up, three to five of these sprints, then doing some shin splint/hamstring work will make a very effective speed training session.
• Flying sprints: After the athlete has consistent technique, these can be introduced into their speed training. This is a little more game-specific in that the athlete must learn to run in different gears. Classically this involves a 20-40 meter run up, followed by sprinting 20-40 meters all out. But, this approach can be modified for athletes to reinforce the need to change gears while having great technique. Again, three to five of these sandwiched in between a warm-up and injury prevention exercises makes an effective workout. For example:
o 20 meter run up
o 10 meters all out
o 10 meter jog
o 10 meters all out
A few quick principles for the strength coach when it comes to speed training in general:
• More is not better. More leads to fatigue, which leads to poor mechanics and learning to run slowly. Both of these are things we don’t want to teach. If our intent is to work on speed, focus on quality over quantity. If our intent is to work on conditioning and mental toughness, then that’s something else but the downside is that by doing 50 40-yard sprints (for example), we’re teaching bad habits.
• Full recovery. Give the athletes two to three minutes between each sprint so they are able to run with good mechanics and at full speed.
• Promote competition. Athletes will perform better with competition, whether it’s against other athletes or against the stopwatch.
• Strengthen the hamstrings. The hamstrings need to be strong in a lengthened position. Lots of RDLs, good mornings, back raises, etc. should be used in a program.
• Focus on one speed quality in each workout. Have a day devoted to acceleration, a day devoted to maximum velocity, etc. You can have more than one day each week devoted to the same thing, but the idea is to focus the athlete in each session. A sample week for a typical field sport athlete might look like:
o Monday: Lower body weights, acceleration
o Tuesday: Upper body weights
o Wednesday: Conditioning
o Thursday: Lower body weights, maximum velocity
o Friday: Upper body weights
o Saturday: Acceleration, plyos
John M. Cissik is Director of Fitness and Recreation at Texas Woman’s University in Denton, Texas and founder of Human Performance Services, LLC, a limited liability company established to provide athletes and their coaches a resource to aid in improving their athletic performance and to develop research based strength and conditioning programming.
In exercise science, the principle of specificity says that “you get what you train for”. Thus, if you train by doing a lot of long distance, jogging, cycling or other forms of “cardio” work you will improve your aerobic fitness, but you won’t improve your ability to perform on the field. Why? Because the art of pitching is an anaerobic activity, not an aerobic activity. Making a pitch takes place in a fraction of a second followed by 20-30 seconds of rest. Success requires strength, speed and power, not aerobic fitness.
If you are doing a lot of cardio, you are not only training a system that you won’t use, you are weakening the primary system (anaerobic system) that you need to be successful in baseball. Research shows that even small amounts of aerobic training (20 minutes a couple of times per week) when combined with strength / power training can decrease both the rate at which you can produce force and your peak power (1). In other words, “if you spend 80% of your training time doing cardio, you are spending 80% of your time practicing to be slow”.
How does aerobic training interfere with speed / power development? First, it causes the body to recruit “slow twitch” muscle fibers over “fast twitch” fibers (2). This shift favors low-force, sustained exercise over the high-force, short duration efforts needed for pitching, and a shift towards slow-twitch fibers is the opposite of what you need for speed / power. Second, it can lead to an increase in cortisol (catabolic hormone) and a decrease in testosterone (anabolic hormone). This hormonal shift encourages muscle wasting over muscle building and lower levels of “naturally” occurring anabolic hormones, including testosterone (3). Can you see any reason to intentionally lower your “naturally” occurring steroids?
Don’t pitchers need endurance? Yes, but not the low-force, steady-state endurance produced by aerobic training. Pitchers need power endurance, i.e., anaerobic endurance. A high level of anaerobic endurance will allow you to throw a baseball 90+ mph, rest for 20-30 sec and repeat it 130 times without a drop in velocity (power).
How do you develop this power? By running high intensity interval sprints (HIT). Research shows the improvements in both aerobic and anaerobic power are significantly higher when athletes run HIT sprints than when they run long distance (5), how long, how hard and how often do you need to run? Very seldom should a pitcher run more than 100 yards and all running should be at or above 70% of max sprint effort. There are a number of effective HIT interval off-season, pre-season and in-season workouts that work. An example of an effective in-season, anaerobic, running program is presented in Table 1.
What about “flush runs” the day after a start to flush out lactic acid and reduce arm soreness? They are not needed for a variety of reasons. First, there is no lactic acid to flush out. There is no accumulation of measurable amounts of lactic acid when you pitch (4). Why? It takes less than 5 sec to make a pitch. It takes 30+ sec of sustained all-out effort to produce lactic acid. The main fuels for pithing are adenosine triphosphate and creatine phosphate (ATP-CP), not lactic acid. ATP-CP are stored in the muscles, re-built in the muscles between pitches and provide the energy needed for HIT efforts lasting up to 6-8 sec. Any effort beyond 6-8 sec uses carbohydrates (blood glucose, muscle glycogen and liver glycogen) to produce energy for HIT muscle contractions and these do not produce lactic acid. The only way a pitcher is going to make measurable quantities of lactic acid is by legging out a triple. The bottom line is that steady-state flush runs interfere with power development. Pitching does not produce lactic acid and even if it did, it would be cleared in less than 24 hours.
So what causes soreness after pitching if not lactic acid? There are several factors. First there is mechanical damage to soft tissue (muscle and muscle-tendon complex). Soreness also occurs as a result of nerve traction forces and general inflammatory mediators recruited for the healing process. Don’t blame lactic acid.
Is there anything about aerobic training that might have benefits to baseball players? Yes, it improves glucose uptake, CP regeneration, blood flow, body composition and strength and endurance in cartilage, tendons and ligaments. However, each of these positive adaptations can be achieved more effectively with HIT interval training without negatively affecting strength, speed and power.
The system used, is the system trained. Doing cardio uses and trains the aerobic system. Doing HIT interval sprints uses and trains the anaerobic (ATP-CP) system. Baseball is an anaerobic sport. Doing cardio not only trains a system that you won’t use, it also interferes with the system that you need for successful performance.
Table 1. Sample In-Season Running Program between Starts
Day After Start
Reps x Distance (yd.)
Rest between reps (sec)
2×100 yd. in 15-20 sec
4×75 in 10-12 sec
6×50 in 6-8 sec
8×25 in 4-5 sec
10×10 in 2 sec
4×75 in 10-12 sec
6×50 in 6-8 sec
8×25 in 4-5 sec
10×10 in 2 sec
6×50 in 6-8 sec
8×25 in 4-5 sec
10×10 in 2 sec
10×50 in 6-8 sec
- Hennessy, LC, Watson, ASW. The interference effects of training strength and endurance simultaneously, J Strength Cond Res, 1994.
- Thayer, et al. A decade of aerobic endurance training: histological evidence for fiber type transformation. J Sports Med Phys Fitness, 2000.
- Kramer, WJ, et al. Compatibility of high intensity strength and endurance training on hormonal and skeletal muscle adaptations. J Appl Physiol, 1995.
- Elliott, MCCS, et al. Power athletes and endurance training. Physiologic and biomechanical rational for change. Sports Med, 2007.
- Tabata I, et.al. Metabolic profile of high intensity intermittent exercises”. Med and Sci in Sports and Exercise, 1997.
Gene Coleman was the Head S&C Coach for the Houston Astros from 1978-2012 and is currently a strength and conditioning consultant for the Texas Rangers.
Everyone in the game of baseball understands the importance of core strength and stability. Hitting and pitching coaches empirically know that the core is where power comes from. Scientists have shown that core strength and stability are necessary to prevent injuries, improve mobility and optimize performance (1, 2). Athletic trainers and strength coaches have used both the empirical evidence provided by position coaches and research provided by scientists as a basis for developing a number of exercise choices. While there seems to be near-universal acceptance of the importance of core strength and stability, until recently there was little consensus as to which exercise or type of exercise is most effective. Current research reveals two key points about core training. First, exercises performed from a standing position are more related to the movements required in game situations than those performed in a horizontal position and second, compound movements are more effective than isolated movements such as crunches and lateral crunches (3, 4,5).
While research indicates that compound, multi-joint movements performed in a horizontal position, such as planks with hand reach, bird dogs with resistance and mountain climbers, are effective for engaging both the deep and proximal muscles of the trunk, we prefer to use these as “level 1” or preparatory exercises for players with stability issues and use sport-specific, multi-joint exercises such as resisted MD ball rotations, chops and lifts to develop the functional core strength and stability needed to reduce the risk of injury and improve performance.
Resisted MD Ball Rotations. Stand in a “ready” position facing a partner. Hold a MD ball at chest level with both arms fully extended and hands on each side of the ball. Set your abs and keep your arms straight and the ball still as your partner applies pressure with one hand on the ball in an attempt to make you rotate to one side. Using eccentric contractions of the muscles of the core slowly resist the rotary force applied to the ball as your body rotates in the direction of the applied force. Rest for 5-10 sec, repeat for the prescribed number of reps, and then repeat the exercise on the opposite side.
Resisted MD Chops. Start from the same position used in the previous exercise holding a MD ball at chest level with both arms fully extended and one hand on top and the other hand under the ball. Your objective in this exercise is to eccentrically resist the downward force (chopping motion) applied by your partner. Rest for 5-10 sec, repeat the exercise for the prescribed number of reps, and then repeat on the opposite side.
Resisted MD Lifts. Start with both arms fully extended and the ball outside one knee. Hold the ball with one hand on top and the other hand under the ball. Your partner kneels down outside the ball and applies and upward (lifting) force to the ball. Your objective is to eccentrically resist the upward (lifting) force applied by your partner. Rest for 5-10 sec, repeat the exercise for the prescribed number of reps, and then repeat on the opposite side.
Jose Vazquez, PT, CSCS
Head Strength Coach, Texas Rangers
Minor League Strength and Conditioning Coordinator, Texas Rangers
- Okada, T., et. al, Relationship Between Core Stability, Functional Movement, and Performance. J Strength Cond Res. 25: 252-261, 2011.
- Brophy, R., et. al. The Core and Hip in Soccer Athletes Compared by Gender. International Journal of Sports Medicine. 30: 663-667, 2009.
- Gottschall, j., et al. Integration Core Exercises Elicit Greater Muscle Activation Than Isolation Exercises. J Strength Cond Res. 27:590—596, 2013.
- Colado, J., et al. The Progression of Paraspinal Muscle Recruitment Intensity in Localized and Global Strength Training Exercise is not Based on Instability Alone. Arch Phys and Med Rehab. 92:1875-1883, 2011..
- Okada, T., et. al, Relationship Between Core Stability, Functional Movement, and Performance. J Strength Cond Res. 25:252-261, 2011.