Research and News
Posts tagged core training
Is resistance training on unstable surfaces effective?
May 6th
Instability training, or exercising while on unstable surfaces, has become both popular and controversial. Performing resistance training on unstable surfaces such as exercise balls, balance boards, stability disks, and foam pads has been shown to reduce force output, but increase activation of “core” muscles of the trunk (Behm and Anderson 2006). No studies, however, have directly compared training outcomes on stable and unstable surfaces.
In a paper published in the Journal of Strength and Conditioning Research, researchers performed a 7 week study of resistance training exercises in 2 groups: one using unstable surfaces and the other on stable surfaces. The researchers hypothesized that the instability resistance training group would demonstrate significantly greater gains in functional testing after the program.
Forty, college-aged, healthy untrained subjects volunteered for the study. Subjects performed squats and vertical jumps, as well as 3 machine-resisted upper body exercises: lat pull down, butterfly, and bench press. Both groups performed upper body exercises at 70% of 1RM. The stable surface training group performed squats at 75% 1RM, and the instability group performed squats at 50% 1RM while balancing on wobble boards, stability discs, or a BOSU ball. The instability group also performed 4 trunk stabilization exercises on an exercise ball. Subjects More >
Stable vs. Unstable: Using Exercise Balls with the Overhead Press Exercise
Apr 29th
“Functional Training” has become increasingly popular in both rehabilitation and fitness. “Core training” has often been considered a component of functional training because of the transfer of force through the trunk to the extremities. Unstable surfaces such as Thera-Band® Exercise Balls and Stability Trainers are often used with traditional exercise movements to integrate training of the trunk and extremities.
Canadian researchers Anderson and Behm have shown that instability training can provide similar muscle activation levels at lower resistance levels compared to training on stable surfaces. Unfortunately, however, unstable surface training also results in a decrease force output of prime movers. California State University researchers set out to evaluate the electromyographic (EMG) activity of prime movers and core stabilizers during a seated overhead press exercise. 30 healthy, resistance-trained subjects performed an overhead press with dumbbells and barbells while sitting on a stable surface and on an exercise ball. The investigators were interested in looking for differences in EMG levels between the stable load (barbell) and unstable load (dumbbell), on both stable (bench) and unstable surfaces (exercise ball). Subjects used a 10RM resistance (maximum amount of weight lifted for 10 repetitions) for each of the 4 conditions; thus, each condition had a slightly different absolute load.
As expected, More >
Exercise ball more effective at activating abdominal muscles
Apr 8th
The exercise ball is a popular device for core training, and is often used to increase muscle activation, particularly of the abdominals. Most studies have concluded that the exercise ball increases electromyographic (EMG) activity of the abdominal muscles. In England, Dr. Michael Duncan investigated the muscle activation in 2 different parts of the rectus abdominus muscle (the upper and lower portions) during exercise both on and off an exercise ball. The 3 exercises were the abdominal curl-up, roll-out, and jack knife. Subjects also performed a curl-up on the floor.
The exercise ball consistently had significantly more rectus activation than the curl-up on the floor. The chart below provides the percent of maximal contraction (MVIC) of each portion of the abdominals during each exercise:
Floor Curl-up Ball Curl-up Jack knife Roll-out Upper Rectus 68% 84% 93% 104% Lower Rectus 64% 93% 111% 98%The study also found that the jack knife was the best exercise for lower abdominal activation compared to all other exercises. This may help clinicians choose an exercise that specifically targets one portion of the abdominals over another. However, some researchers suggest that isolating one muscle may not be beneficial for core stabilization, instead focusing on quick and strong activation of More >
Training program improves throwing accuracy in baseball players
Mar 31st
Core training is thought to be important to improve functional sport activities, particularly those involving force transfer through the abdominals and back, into the extremities. For example, much of the strength and power required to throw a baseball comes from the force transmitted through the core from the legs. This is an example of the ‘kinetic chain,” where different parts of the body are interconnected and all contribute in some way to performing a functional activity.
Few studies have investigated the effects of core training on functional performance. Athletic training researchers investigated the effects of a shoulder training program with and without core stability exercises. 19 baseball players were randomly assigned to an open and closed-chain exercise program, or the same program with additional core training. 15 healthy age-matched non athletes were used as a quasi-control group. Each subject was tested for throwing accuracy, core stability, and proprioception before and after the 6-week program.
Both groups performed a shoulder training program that included free weights, closed-chain balance board, step-up, and exercise ball exercises, as well as plyometric ball tosses. The core training group also performed stabilization exercises such as the dead bug, sit-up, bridge, wall slides, and sitting on an exercise ball.
After the training program, More >
Musculoskeletal Injury Prevention & Performance Enhancement Screening for Professional Tennis Players
May 16th
by Todd S. Ellenbecker, DPT, MS, SCS, OCS, CSCS
For the last three years, the Association of Tennis Professionals (ATP) has provided musculoskeletal screenings to its players at the Italian Open in Rome Italy. Led by orthopedic surgeon Dr. Gary Windler of Charleston, South Carolina, and physical therapist Todd Ellenbecker of Scottsdale, Arizona, these screenings consist of a series of musculoskeletal tests focusing on scapula and core stability, rotator cuff strength, and both upper and lower body flexibility and range of motion measurement.
Testing with Thera-Band Soft Weights
One of the key components of this program is the immediate follow-up of exercises for tennis players following their testing. Results are immediately tabulated and shared with the player, his coach, and physiotherapist, and often their personal strength and conditioning specialist. Based on the test results, players are given a series of individualized, tennis-specific exercises which utilize the Thera-Band® product line. These include Thera-Band elastic bands, tubing, and loops; Stability Trainers, Pro Series exercise balls, FlexBars, and Soft Weights. These products have been chosen due to their effectiveness as well as for their portability since professional tennis players travel most weeks of the year and need to have their exercise programs accessible to them at all times. Exercises to increase the strength More >
