Swiss Balls and Stability Training Research
(References for the article “Swiss Balls and Stability Training: Effective Workout or Pointless Fad?“)
1. Anderson KG, Behm DG. (2004). Maintenance of EMG activity and loss of force output with instability. Journal of Strength and Conditioning Research. 18(3): 637-40.
Experiment: The objective of this study was to measure differences in force output and electromyographic (EMG) activity of the pectoralis major, anterior deltoid, triceps, latissimus dorsi, and rectus abdominus for isometric and dynamic contractions under stable and unstable conditions. Ten healthy male subjects performed a chest press while supported on a bench or a Swiss Ball.
Conclusions: (1) “Unstable isometric maximum force output was 59.6% less than under stable conditions. However, there were no significant differences in overall EMG activity between the stable and unstable protocols”, (2) “Greater EMG activity was detected with concentric vs. eccentric or isometric contractions”, (3) “The decreased balance associated with resistance training on an unstable surface may force limb musculature to play a greater role in joint stability”, (4) “The diminished force output suggests that the overload stresses required for strength training necessitate the inclusion of resistance training on stable surfaces”.
2. Bair C, Buckley B, Pralle R, Schroeter M, Smith B, Jorgensen1 M. (2009). Shoulder muscle EMG activity in women during push up on varying surfaces. Proceedings of the 5th Annual GRASP Symposium, Wichita State University.
Experiment: 18 female college students were recruited to perform a push up on a BOSU® ball and on an exercise bench while EMG muscle activity was measured in 7 muscles (biceps, triceps, rectus abdominus, external oblique, pectoralis major, latissimus dorsi, and posterior deltoid).
Conclusions: (1) Overall, muscles used during a push up performed on the bench showed the greatest EMG muscle activity, (2) “Unexpectedly, the greatest EMG muscle activity occurred in the rectus abdominus and the triceps muscles on the bench push up compared to the standard push up and the unstable push up”, (3) “This study showed a significant increase in EMG muscle activity during the bench push up compared to the BOSU pushup, contradicting the finding of previous research.”
3. Behm DG, Anderson K, Curnew RS. (2002). Muscle force and activation under stable and unstable conditions. Journal of Strength and Conditioning Research. 16(3): 416-22.
Experiment: The objective of this study was to determine differences in isometric force output, muscle activation (interpolated twitch technique), and EMG activity of the quadriceps, plantar flexors (PF), and their antagonists under stable and unstable conditions. Instability in subjects was introduced by making them perform contractions while seated on a “Swiss ball”. Eight male subjects performed unilateral leg extensor (LE) and PF contractions while seated on a bench (LE), chair (PF), or a ball.
Conclusions: (1) “Swiss balls may permit a strength training adaptation of the limbs, if instability is moderate, allowing the production of overload forces”, (2) Unstable LE and PF forces were 70.5 and 20.2% less than their stable counterparts, (3) Unstable quadriceps and PF activation averaged 44.3 and 2.9% less than activation under stable conditions, (4) Unstable antagonist/agonist ratios were 40.2 and 30.7% greater than stable ratios in the LE and PF protocols.
4. Behm DG, Burry SM, Greeley GED, Poole AC, Mackinnon SN. (2006). An unstable base alters limb and abdominal activation strategies during the flexion-relaxation response. Journal of Sports Science and Medicine. 5: 323-332.
Experiment: The study compared 14 subjects (7 men, 7 women) who flexed at the hips and back while standing on a stable floor or an unstable dyna-disc while EMG readings were taken of select trunk and leg muscles to test for the flexion-relaxation phenomenon of the erector spinae.
Conclusions: Found no effect of an unstable base on the flexion-relaxation response of the upper lumbar erector spinae and lumbo-sacral erector spinae. It was hypothesized that the greater instability of the dyna-disc was dampened to some extent by the greater activity of the plantar flexors and biceps femoris.
5. Behm DG, Leonard AM, Young WB, Bonsey WA, MacKinnon SN. (2005). Trunk muscle electromyographic activity with unstable and unilateral exercises. Journal of Strength and Conditioning Research. 19(1): 193-201.
Experiment: Eleven subjects (6 men and 5 women) between 20 and 45 years of age were used to evaluate the effect of unstable and unilateral resistance exercises on trunk muscle activation. Six trunk exercises, as well as unilateral and bilateral shoulder and chest presses against resistance, were performed on stable (bench) and unstable (Swiss ball) bases. EMG activity of the upper lumbar, lumbosacral erector spinae, and lower-abdominal muscles was monitored.
Conclusions: Instability generated greater activation of the lower-abdominal stabilizer musculature (27.9%) with the trunk exercises and all trunk stabilizers (37.7-54.3%) with the chest press, (2) There was no effect of instability on the shoulder press, (3) Unilateral shoulder press produced greater activation of the back stabilizers, (4) Unilateral chest press resulted in higher activation of all trunk stabilizers, when compared with bilateral presses, (5) Regardless of stability, the superman exercise was the most effective trunk-stabilizer exercise for back-stabilizer activation, (6) The side bridge was the optimal exercise for lower-abdominal muscle activation (again regardless of the stability).
6. Clark KM, Holt LE, Sinyard J. (2003). Electromyographic comparison of the upper and lower rectus abdominis during abdominal exercises. Journal of Strength and Conditioning Research. 17(3): 475-83.
Experiment: 8 healthy adults were used to assess the effects of 6 different abdominal exercises (curl up, Sissel ball curl up, Ab Trainer curl up, leg lowering, Sissel ball roll out, and reverse curl up) on the electrical activity of the upper rectus abdominis (URA) and lower rectus abdominis (LRA).
Conclusions: (1) Both the URA and the LRA recorded significantly higher mean amplitudes during the Sissel ball curl up than during all other exercises, (2) The curl up, Sissel ball curl up, and Ab Trainer curl up had significantly higher normalized EMG activity in both muscle sites than the reverse curl up, the leg lowering exercise, and the Sissel ball roll out, (3) The curl up and the Ab Trainer curl up exercises were not significantly different in terms of their normalized EMG activities for both the URA and the LRA.
7. Cowley PM, Swensen T, Sforzo GA. (2007). Efficacy of instability resistance training. International Journal of Sports Medicine. 28(10): 829-35.
Experiment: 14 women performed a 1 repetition maximum (1RM) barbell chest-press and the YMCA bench press test (YBT) on a stability ball and flat bench, as well as two field tests measuring abdominal power (front abdominal power test and side abdominal power test). The purpose of the study was to evaluate the influence of platform (unstable vs. stable / stability ball vs. flat bench) on strength and work capacity during barbell chest-press as well as to determine the effects of a barbell chest-press training program performed on a stability ball or flat bench on strength, work capacity, and abdominal power.
Conclusions: (1) “Platform (stability ball vs. flat bench) had no influence on strength, but work capacity was initially 12 % lower on the stability ball”, (2) “The increase in work capacity was 32% and 13% on the stability ball and flat bench for the stability ball group, and 27% and 26% for the flat bench group, respectively”, (3) Performance on the front abdominal power test improved by 5% for the stability Ball group, and 22% for the flat bench group, (4) Performance on the side abdominal power test did not change for either group.
8. Drake JD, Fischer SL, Brown SH, Callaghan JP. (2006). Do exercise balls provide a training advantage for trunk extensor exercises? A biomechanical evaluation. Journal of Manipulative and Physiological Therapeutics. 29(5): 354-62.
Experiment: Bilateral muscle activation was recorded from 7 sites (rectus abdominis, external/internal obliques, latissimus dorsi, thoracic/lumbar erector spinae, and multifidus) on 8 subjects. Three-dimensional lumbar spine postures and upper body kinematics were recorded while the participants performed the exercises on both a mat and an exercise ball.
Conclusions: (1) Cocontraction of trunk flexor and extensor muscles was reduced by up to 30% for the extension exercises when performed on the ball, (2) Peak muscle activation remained unchanged or decreased, and spinal loading decreased when the extension exercises were performed on the ball (the lumbar spine postures attained during the exercises did not differ between surfaces), (3) “The assumption that the use of an exercise ball will always create a greater challenge for the musculoskeletal system was not supported…Likewise, in a healthy, young population, there does not appear to be any training advantage to performing extensor exercises on a ball versus a mat.”
9. Drinkwater EJ, Pritchett EJ, Behm DG. (2007). Effect of instability and resistance on unintentional squat-lifting kinetics. International Journal of Sports Physiology and Performance. 2(4):400-13.
Experiment: Fourteen active men performed sets of 3 repetitions of squats under conditions of increasing instability. Each session consisted of standing on a stable floor, foam pads, or BOSU balls.
Conclusions: “Resistance training in an unstable environment at an intensity sufficient to elicit strength gains of the prime movers results in deleterious effects in concentric squat kinetics and squat technique.”
10. Duncan M. (2009). Muscle activity of the upper and lower rectus abdominis during exercises performed on and off a Swiss ball. Journal of Bodywork and Movement Therapies. 13(4): 364-367.
Experiment: 14 healthy adults (7 male, 7 female) were tested to examine differences in upper rectus abdominis and lower rectus abdominis muscle activity during four abdominal exercises (the curl-up, Swiss ball curl-up, Swiss ball jackknife and Swiss ball rollout) using a Swiss Ball and EMG readings.
Conclusions: Muscle activity was greater when exercises were performed on a Swiss ball in comparison to a stable surface.
11. Goodman CA, Pearce AJ, Nicholes CJ, Gatt BM, Fairweather IH. (2008). No difference in 1RM strength and muscle activation during the barbell chest press on a stable and unstable surface. Journal of Strength and Conditioning Research. 22(1): 88-94.
Experiment: “This study compared 1RM strength, and upper body and trunk muscle EMG activity during the barbell chest press exercise on a stable (flat bench) and unstable surface (exercise ball).”
Conclusions: (1) ” The results show that there was no difference in 1RM strength or muscle EMG activity for the stable and unstable surfaces”, (2) “…there was no difference in elbow range-of-motion between the two surfaces”, (3) “…these results do not support the notion that resistance exercises performed on an exercise ball are more efficacious than traditional stable exercises.”
12. Hamlyn N, Behm DG, Young WB. (2007).Trunk muscle activation during dynamic weight-training exercises and isometric instability activities. Journal of Strength and Conditioning Research. 21(4): 1108-12.
Experiment: Sixteen subjects performed squats and deadlifts with 80% 1 repetition maximum (1RM), as well as with body weight as resistance and 2 unstable calisthenic-type exercises (superman and sidebridge). EMG activity was measured from the lower abdominals (LA), external obliques (EO), upper lumbar erector spinae (ULES), and lumbar-sacral erector spinae (LSES) muscle groups.
Conclusions: (1) “…the augmented activity of the LSES and ULES during 80% 1RM squat and deadlift resistance exercises exceeded the activation levels achieved with the same exercises performed with body weight and selected instability exercises”, (2) “Individuals performing upright, resisted, dynamic exercises can achieve high trunk muscle activation and thus may not need to add instability device exercises to augment core stability training.”
13. Kohler JM, Flanagan SP, Whiting WC. (2009). Muscle activation patterns while lifting stable and unstable loads on stable and unstable surfaces. Department of Kinesiology, California State University, Northridge.
Experiment: Thirty resistance-trained subjects performed the shoulder press exercise for 3 sets of 3 repetitions under 2 load (barbell, dumbbell) and 2 surface (exercise bench, Swiss ball) conditions at a 10RM relative intensity. Surface electromyography (EMG) measured muscle activity for 8 muscles (anterior deltoid, middle deltoid, trapezius, triceps brachii, rectus abdominis, external obliques, and upper and lower erector spinae).
Conclusions: (1) “The findings provide little support for training with a lighter load using either unstable loads and/or unstable surfaces”, (2) “Based on the muscle activation patterns, our results do not support the use of training with dumbbells or Swiss Balls over training with the heavier loads associated with a barbell on an exercise bench for developing core musculature during the overhead lift”.
14. Lehman, GJ. (2007). An unstable support surface is not a sufficient condition for increases in muscle activity during rehabilitation exercise. Journal of the Canadian Chiropractic Association. 51(3): 139–143.
Experiment: Examination of current literature related to the title.
Conclusions: (1) “… just as not all muscles increase their activation levels during push ups when performed on an unstable surface (e.g. pectoralis major, external oblique) not all individuals respond in a similar manner to changes in surface stability…”, (2) “Merely adding labile surfaces may not increase the load on the neuromuscular system for specific patients. An argument can even be made that adding Swiss balls to certain exercises (wall squats and spine extensor exercises) decreases the stress on the musculature due to decreases in muscle activation following the incorporation of a Swiss ball.”
15. Lehman GJ, Gilas D, Patel U. (2008). An unstable support surface does not increase scapulothoracic stabilizing muscle activity during push up and push up plus exercises. Manual Therapy. 13(6): 500-6.
Experiment: 10 males participated in the study, which measured EMG readings of the upper trapezius, lower trapezius, serratus anterior and biceps brachii while performing push up exercises with the feet or hands placed on a bench and separately on a Swiss ball.
Conclusions: (1) “There was no statistically significant difference in mean EMG amplitude on a Swiss ball when compared with the same exercise performed on a bench”, (2) “Significant differences in muscle activity were seen in the upper trapezius and serratus anterior as a result of changes in foot position relative to hand position irrespective of surface stability.”
16. Lehman GJ, Gordon T, Langley J, Pemrose P, Tregaskis S. (2005). Replacing a Swiss ball for an exercise bench causes variable changes in trunk muscle activity during upper limb strength exercises. Dynamic Medicine. 4:6.
Experiment: Participants performed 5 different upper-body resistance exercises while the myoelectric activity of 4 trunk muscles was monitored. Swiss Balls were compared to a fixed weight bench.
Conclusions: (1) “Selected trunk muscle activity during certain upper limb strength training exercises is not consistently influenced by the replacement of an exercise bench with a swiss ball”, (2) “These findings suggest that the incorporation of swiss balls instead of an exercise bench into upper body strength training regimes may not be justified based only on the belief that an increase spinal stabilizing musculature activity is inherent. Biomechanically justified ground based exercises have been researched and should form the basis for spinal stability training as preventative and therapeutic exercise training regimes.”
17. Lehman GJ, Hoda W, Oliver S. (2005). Trunk muscle activity during bridging exercises on and off a Swiss ball. Chiropractic & Osteopathy. 13: 14.
Experiment: Compared myoelectric activity in 4 trunk muscles in both prone and supine bridging exercises on and off a Swiss Ball.
Conclusions: (1) The addition of an exercise ball didn’t affect the Internal Oblique or Erector Spinae in either bridging exercise, (2) The addition of an exercise ball didn’t affect the Rectus Abdominus or External Oblique during a supine bridge, but did during a prone bridge.
18. Lehman GJ, MacMillan B, MacIntyre I, Chivers M, Fluter M. (2006). Shoulder muscle EMG activity during push up variations on and off a Swiss ball. Dynamic Medicine. 5:7.
Experiment: Thirteen males were used and surface electromyograms were recorded from the triceps, pectoralis major, latissimus dorsi, rectus abdominis and external oblique while performing push up exercises with the feet or hands placed on a bench and separately on a Swiss ball.
Conclusions: (1) “Not all muscles responded with an increase in muscle activity”, (2) “The pectoralis major muscle was not influenced by surface stability”, (3) The triceps and rectus abdominis muscles showed increases in muscle activity only when the hands were on the unstable surface”, (4) “The external oblique muscle was only influenced by surface stability during the performance of the push up plus exercise”, (5) “No muscle showed a change in activation level when the legs were supported by the Swiss ball instead of the bench”, (6) “Muscle activity can be influenced by the addition of surface instability however an increase in muscle activity does not influence all muscles in all conditions.”
19. Marshall P, Murphy B. (2006). Changes in muscle activity and perceived exertion during exercises performed on a swiss ball. Applied Physiology, Nutrition, and Metabolism. 31(4): 376–383.
Experiment: Twelve healthy subjects performed squats, push ups and double leg lowering with a Swiss Ball while the differences in EMG activity of prime mover and abdominal muscles were recorded.
Conclusions: The Swiss Ball increased muscle activity only when it was the base of support.
20. Marshall PW, Murphy BA. (2005). Core stability exercises on and off a Swiss ball. Archives of Physical Medicine and Rehabilitation. 86(2): 242-9.
Experiment: 8 healthy volunteers were used to assess lumbopelvic muscle activity during 4 different core stability exercises (inclined press-up, upper body roll-out, single-leg hold, and quadruped exercise) on and off a Swiss ball with EMG measurements.
Conclusions: “Although there was evidence to suggest that the Swiss ball provides a training stimulus for the rectus abdominus, the relevance of this change to core stability training requires further research because the focus of stabilization training is on minimizing rectus abdominus activity.”
21. Marshall PW, Murphy BA. (2006). Increased deltoid and abdominal muscle activity during Swiss ball bench press. Journal of Strength and Conditioning Research. 20(4): 745-50.
Experiment: 14 resistance-trained subjects were used to investigate muscle activity using surface EMG of upper-body and abdominal muscles during the concentric and eccentric phases of the bench press on a Swiss Ball compared to on a bench press machine.
Conclusions: (1) Deltoid and abdominal muscle activity was increased for repetitions performed using the swiss ball, (2) “Provides scientific evidence for anecdotal reasoning behind swiss ball use as a potential core stability training device”, (3) “This study demonstrates that the acute effect of utilizing the Swiss Ball in the performance of bench press exercise is an increase in the muscle activity of stability muscles associated with the task”, (4) “The Swiss Ball did not lead to increased activity for the prime movers of the exercise, the pectoralis and triceps”.
22. Martins J, Tucci HT, Andrade R, Araújo RC, Bevilaqua-Grossi D, Oliveira AS. (2008). Electromyographic amplitude ratio of serratus anterior and upper trapezius muscles during modified push-ups and bench press exercises. Journal of Strength and Conditioning Research. 22(2): 477-84.
Experiment: The study aimed to identify exercises that would selectively activate the upper trapezius and serratus anterior (UT/SA) muscles for use in rehabilitation. 12 healthy men were tested with surface EMG of the trapezius and serratus anterior as they performed isometric contractions over a stable base of support and on a Swiss ball during wall push-up (WP), bench press (BP), and push-up (PU) exercises.
Conclusions: “The results demonstrate that UT/SA ratio was influenced by the exercises and by the upper limb base of support. The practical application is to show that BP on a stable surface is the exercise preferred over WP and PU on either surfaces for serratus anterior muscle training in patients with imbalance between the UT/SA force couple or serratus anterior weakness.”
23. McBride, JM, Cormie P, Deane R. (2006). Isometric Squat Force Output and Muscle Activity in Stable and Unstable Conditions. The Journal of Strength and Conditioning Research. 20(4): 915-918.
Experiment: The purpose of this study was to assess the effect of stable vs. unstable conditions on force output and muscle activity during an isometric squat. Nine men involved in recreational resistance training participated in the investigation by completing a single testing session. Within this session subjects performed isometric squats either while standing directly on the force plate (stable condition, S) or while standing on inflatable balls placed on top of the force plate (unstable condition, U). EMG was recorded during both conditions from the vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), and medial gastrocnemius (G) muscles.
Conclusions: “The primary finding in this investigation is that isometric squatting in an unstable condition significantly reduces peak force, rate of force development, and agonist muscle activity with no change in antagonist or synergist muscle activity. In terms of providing a stimulus for strength gain no discernable benefit of performing a resistance exercise in an unstable condition was observed in the current study.”
24. Norwood JT, Anderson GS, Gaetz MB, Twist PW. (2007). Electromyographic activity of the trunk stabilizers during stable and unstable bench press. Journal of Strength and Conditioning Research. 21(2): 343-7.
Experiment: Surface EMG was measured from 6 muscles (latissimus dorsi, rectus abdominus, internal obliques, erector spinae, and soleus) while subjects performed a 9.1-kg bench press on stable and unstable surfaces. There were 4 exercises in total: (a) stable surfaces for shoulders and feet, (b) upper-body instability, (c) lower-body instability, and (d) dual instability.
Conclusions: “The results show significant increases in EMG with increasing instability. Specifically, the dual instability bench press resulted in the greatest mean muscle activation of the 3 stability conditions, with single instability conditions being significantly greater than the stable condition. This pattern of results is consistent with the position that performing the bench press in a progressively unstable environment may be an effective method to increase activation of the core stabilizing musculature…”
25. Nuzzo JL, McCaulley GO, Cormie P, Cavill MJ, McBride JM. (2008).Trunk muscle activity during stability ball and free weight exercises. Journal of Strength and Conditioning Research. 22(1): 95-102.
Experiment: 9 resistance-trained men participated in one testing session in which squats (SQ) and deadlifts (DL) were completed with loads of approximately 50, 70, 90, and 100% of one-repetition maximum (1RM). Isometric contractions during 3 stability ball exercises (quadruped, pelvic thrust, ball back extension) were also completed. During all exercises, average integrated EMG from the rectus abdominus, external oblique, longissimus, and multifidus were compared.
Conclusions: “…activity of the trunk muscles during SQs and DLs is greater or equal to that which is produced during the stability ball exercises. It appears that stability ball exercises may not provide a sufficient stimulus for increasing muscular strength or hypertrophy; consequently, the role of stability ball exercises in strength and conditioning programs is questioned.”
26. Petrofsky JS, Batt J, Davis N, Lohman E, Laymon M, De Leon GE, Roark H, Tran TM, Ayson EG, Vigeland KM, Payken CE. (2007). Core muscle activity during exercise on a mini stability ball compared with abdominal crunches on the floor and on a Swiss ball. Journal of Applied Research. 7(3).
Experiment: Ten subjects were examined to determine muscle use that occurred during core body exercise using a 7-inch diameter mini stability ball compared with abdominal crunches on the floor and on a Swiss Ball. Muscle use was evaluated through the surface EMG recorded above the abdominal and lower back muscles.
Conclusions: (1) Crunches on the Swiss ball used approximately 50% more muscle work per second of exercise as did work with floor crunches, (2) The lightest exercise (sitting crunches with the mini stability ball behind the back) was about equal to half of the work per second as floor crunches, (3) the most intense exercises with the mini ball were as much as 4 times the work as abdominal crunches per second of exercise, (4) The greatest difference in the mini stability ball exercise was seen when the degree of flexion/extension was increased from 50 to 90 degrees (which cannot be accomplished with standard floor crunches or with the Swiss Ball due to its larger diameter and size).
27. Stanton R, Reaburn P, Humphries B. Swiss ball training: current research and future recommendations. Australian Conference of Science and Medicine in Sport 2002.
Experiment: Examination of current literature related to the title.
Conclusions: (1) “… empirical data to support the claims made by clinicians, trainers and users of Swiss Balls are lacking”, (2) “Data from Swiss Ball studies conducted thus far indicate greater activation of the abdominal musculature, when compared to other forms of abdominal training”, (3) “Moreover…it appears Swiss Ball training may lead to greater core stability, however this is not reflected by superior athletic performance”, (4) The study noted that due to poor standards of quantification for the measurement of core stability, “the prescription of Swiss Ball exercises should be viewed with caution”.
28. Stanton R, Reaburn PR, Humphries B. (2004). The effect of short-term Swiss ball training on core stability and running economy. Journal of Strength and Conditioning Research. 18(3): 522–528.
Experiment: 18 young male athletes were tested for six weeks to determine the effects of using a Swiss Ball on core stability and running economy, with assessments conducted both before and after for stature, body mass, core stability, EMG activity of the abdominal and back muscles, treadmill VO2 max, running economy, and running posture.
Conclusions: (1) While data analysis revealed a significant effect of Swiss ball training on core stability in the experimental group, no significant differences were observed for myoelectric activity of the abdominal and back muscles, treadmill VO2 Max, running economy, or running posture, (2) “It appears Swiss ball training may positively affect core stability without concomitant improvements in physical performance in young athletes.”
29. Verhagen E, van der Beek A, Twisk J, Bouter L, Bahr R, van Mechelen W. (2004). The effect of a proprioceptive balance board training program for the prevention of ankle sprains: a prospective controlled trial. American Journal of Sports Medicine. 32(6): 1385-1393.
Experiment: 116 male and female volleyball teams (66 intervention teams with 641 players; 50 control teams with 486 players) were followed prospectively during the 2001–2002 season. Intervention teams followed a prescribed balance board training program; control teams followed their normal training routine. The coaches recorded exposure on a weekly basis for each player and injuries were registered by the players within 1 week after onset.
Conclusions: (1) Significantly fewer ankle sprains in the intervention group were found compared to the control group, (2) A significant reduction in ankle sprain risk was found only for players with a history of ankle sprains, (3) The incidence of overuse knee injuries for players with history of knee injury was increased in the intervention group, (4) History of knee injury may be a contraindication for proprioceptive balance board training.
30. Wahl MJ, Behm DG. (2008). Not all instability training devices enhance muscle activation in highly resistance-trained individuals. Journal of Strength and Conditioning Research. 22(4): 1360-70.
Experiment: The objective of this study was to measure the EMG activity of the soleus, bicep femoris, rectus femoris, lower abdominal, and lumbosacral erector spinae muscles with a variety of instability devices, stable and unstable exercises, and a fatiguing exercise in 16 highly conditioned individuals. Devices used included Dyna Disc, BOSU ball, wobble board, and a Swiss ball.
Conclusions: (1) The experiment found increased activity for all muscles when standing on a Swiss ball and all muscles other than the rectus femoris when standing on a wobble board, (2) Only lower abdominals and soleus EMG activity increased while squatting on a Swiss ball and wobble board, (3) Devices such as the Dyna Disc and BOSU ball did not exhibit significant differences in muscle activation under any conditions, except the lumbosacral erector spinae in the standing Dyna Disc conditions, (4) During the exercise protocol, there were no significant changes in muscle activity between stable and unstable conditions, (5) With the fatigue protocol, soleus EMG activity was 51% greater with a stable base, (6) These results indicate that the use of moderately unstable training devices did not provide sufficient challenges to the neuromuscular system in highly resistance-trained individuals.
31. Willardson JM. (2007). Core stability training: applications to sports conditioning programs. Journal of Strength and Conditioning Research. 21(3): 979-85.
Experiment: Examination of current literature related to the title.
Conclusions: (1) “Based on the current literature, prescription of core stability exercises should vary based on the phase of training and the health status of the athlete”, (2) Preseason and in-season: “…free weight exercises performed while standing on a stable surface are recommended for increases in core strength and power. Free weight exercises performed in this manner are specific to the core stability requirements of sports-related skills due to moderate levels of instability and high levels of force production”, (3) Postseason and off-season: “Swiss ball exercises involving isometric muscle actions, small loads, and long tension times are recommended for increases in core endurance. Furthermore, balance board and stability disc exercises, performed in conjunction with plyometric exercises, are recommended to improve proprioceptive and reactive capabilities”.
32. Willardson JM, Fontana F, Bressel E. (2009). Effect of surface stability on core muscle activity for dynamic resistance exercises. International Journal of Sports Physiology and Performance. 4(1).
Experiment: Twelve trained men performed the back squat, dead lift, overhead press, and curl lifts. The activity of the rectus abdominis, external oblique abdominis, transversus abdominis/internal oblique abdominis, and erector spinae muscles was assessed both on stable ground as well as on a BOSU Balance Trainer.
Conclusions: “The current study did not demonstrate any advantage in utilizing the BOSU Balance Trainer. Therefore, fitness trainers should be advised that each of the aforementioned lifts can be performed while standing on stable ground without losing the potential core muscle training benefits.”
33. The Truth on Fitness: Should We Use Unstable Surfaces? by Paul M. Juris. Cybex Institute, March 2009.
34. The Case Against Stability Training, Bigger Faster Stronger, Mar/April 2007, pp. 70-72.