Research and News
Research Updates
Why is force output decreased while sitting on an exercise ball? The core stability debate continues.
Jun 3rd
“Core Stability” has become a very popular term when discussing topics ranging from functional performance in athletes to rehabilitation for patients with low back pain. The exercise ball has long been used to promote core stability through specific exercises aimed at activating core muscles including the abdominals, low back, and pelvic stabilizers. The use of unstable surfaces such as a Thera-Band® exercise ball has been shown to increase muscle activity compared to a stable surface by providing additional challenge to postural stability. Researchers have shown, however, that exercises on an unstable surface reduce force output, suggesting that traditional resistance training exercises should not be performed on an unstable surface when the goal is to increase core activation. This lack of force output on unstable surfaces is thought to be related to a lack of core stability.
Researchers in New Zealand set out to determine if the loss in force output while performing an overhead press exercise on an exercise ball was related to core muscle endurance. They were interested in the ‘specificity vs. generality” of core stability; in other words, is core stability related to overall physical performance, or simply a measure of core muscle endurance?
30 resistance-trained, healthy young males participated in the study. More >
Exercise with Thera-Band® Stability Trainers helps improve dynamic balance in patients with hip osteoarthritis and replacement
Jun 1st
According to the American Academy of Orthopedic Surgeons, there are over 200,000 hip replacements performed each year in the United States. The most common reason for hip replacement is osteoarthritis, the most common form of arthritis. “Hip School,” an exercise program for patients with osteoarthritis and hip replacement was developed in Germany in 1995 by orthopedic surgeon Thomas Horstmann and physiotherapist Georg Haupt. In the program, small groups of patients (10-15) exercise under the supervision of a physical therapist. Home exercises are also performed 3 to 4 times per week. The exercises focus on strength and balance exercises for 20 minutes, including:
- 1-leg balance, 15-30 seconds for 5 reps on each leg
- 1-leg balance with opposite leg movement for 1 to 3 sets of 15-25 reps
- Hip lift for 3 sets of 15-25 reps
- 2-leg calf raise with 2-second hold, 1 to 3 sets for 15 to 25 reps.
- Patients progress from a stable surface to Thera-Band Stability Trainers.
In a paper published in the Journal of Geriatric Physical Therapy, German researchers wanted to compare their Hip School participants with a non-exercising control group of hip patients. Each group was tested before and after 3 months using an oscillating platform (Posturomed®) to measure their static and dynamic balance. More >
Thera-Band® strength training for older adults: from acute care to home exercise
May 27th
One of the most common clinical mistakes is to arbitrarily assign resistance training levels to older adults, often choosing very low intensities. These low loads are often insufficient to increase muscle strength. Drs. Dale Avers and Marybeth Brown of the American Physical Therapy Association’s Section on Geriatrics published a whitepaper in the Journal of Geriatric Physical Therapy on strength training for older adults.
Both the Section on Geriatrics and the American College of Sports Medicine recommend strength training at 60% of 1 repetition maximum (RM) as the minimal intensity for strength gains. 1RM is the maximal amount of resistance an individual can move for only one repetition. Unfortunately, it’s often difficult to determine 1RM capabilities in older adults. Even using a multiple RM equation to estimate 1RM may not be accurate, since they haven’t been validated in older adults. However, using Thera-Band® resistance to quantify a multiple RM level has been validated in older adults (Manor et al.)
Using a “rating of perceived exertion” or RPE scale has been advocated to better estimate resistance exercise intensity. There are 2 popular RPE scales: the Borg scale and Omni scale. Several studies on older adults using elastic resistance have used Borg’s RPE scale to dose intensity, and More >
What to consider when combining elastic and traditional barbell exercises
May 20th
Strength and conditioning professionals have been adding elastic resistance bands to traditional squat and bench press exercises. It’s thought that adding elastic bands to these traditional barbell exercises will increase force output. Researchers at Loyola Marymount University in Los Angeles published a paper in the Journal of Strength and Conditioning Research that quantified the force production of thick elastic bands during elastic-augmented barbell exercises.
The researchers noted that the exact loading pattern provided by elastic bands needs to be quantified for programming optimal exercise variables. They were concerned with 3 variables: the thickness of the bands, the attachment of the band, and the exercise performed. The researchers attached different thicknesses of bands as they would be used during a bench press or squat. Four elastic band lengths were used for bench press compared to 2 lengths for the squat. Elastic force was determined as the bands were stretched 200 to 300%, and prediction equations were calculated. As expected, the bench press set-up (4 band length equivalents) produced about twice as much force and slope as the squat (2 band length equivalents).
It’s important for practitioners to know the volume of exercise during a combined free weight plus elastic band exercise. The authors suggest that More >
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 >
