A 10-Week Training Study Comparing Resistaball® and Traditional Trunk Training

The Resistaball^® is an inflatable plastic ball designed for “stability training” of the trunk. The purpose of this study was to compare traditional floor work (T) with Resistaball^® exercise (R) in training the abdominal and back extensor muscles. Fifty-five female subjects ranging in age from 20 to 40 years participated in the study. The T group (15 subjects) and R group (20 subjects) participated in pretesting, 10-weeks of exercise, and post-testing; while the non-exercising controls (C group; 20 subjects) participated only in pretesting and post-testing. The exercise program for both the T and R groups consisted of crunches, oblique twists, and back extensions on the floor (T) or ball (R). Subjects performed no other abdominal or back training over the 10-week period. The pretest and post-test consisted of double leg lowering (DLL), trunk flexion (AB), and back extension (BE). For DLL, each subject was supine with hips flexed at 90° and was asked to slowly lower both legs. The point at which there was any movement at the lower back or pelvis was measured using a Universal goniometer. The AB and BE tests were conducted on Cybex^® machines. Subjects self-selected a resistance they determined to be “somewhat hard to hard” and flexed or extended repeatedly against that resistance to volitional failure or until they were unable to perform the movement correctly. During post-testing, subjects completed the AB and BE tests to volitional failure using the pretest resistance. A one-way ANOVA with paired t-tests and General Linear Model were used to analyze the data for initial differences, net gain, percent gain, and group factor. For DLL, those in the R group using the Resistaball^® improved significantly more than either those who used traditional floor work or controls (p < 0.05). For AB, there was no significant difference between any of the groups (p > 0.05). For BE, both those who used Resistaball^® training and those who used traditional floor work improved significantly more than controls (p < 0.05), but there was no difference between the R and T groups (p > 0.05). In conclusion, exercise training with the Resistaball^® was comparable to traditional floor work for training the abdominal and back muscles and may be of greater benefit for functional activities that require spinal and pelvic stabilization.