righting, protective and equilibrium reactions
The antigravity, balance and power producing capacity of the body can be simply thought of, in terms of physical skills, as righting, protective and equilibrium reactions.
Automatic righting reactions maintain or restore body alignment as it relates to the position of the head, trunk and limbs. Muscle spindles monitor the rate at which muscles lengthen and play a big role in maintaining balance at rest. Spindle feedback helps the body stay centered while standing on the Balance Trainer dome and visually tracking one hand from in front of the body to the side, and then to an overhead position. Muscle spindles also play a role when trying to maintain balance over the center of the dome with the eyes closed. When a body part is suddenly displaced, righting reactions come into play. An arm or leg shooting up or out to the side counters the weight displacement and is largely automatic, thanks to sensory feedback coming from the muscle spindles. If weight shifts are slow and controlled, constant muscular activity and adjustment is subtle, rather than dramatic.
Equilibrium reactions can be thought of as an integration of righting and protective reactions as the body fine tunes, through practice, a coordinated, complex and automatic response. The aim of the response is to preserve or restore balance during any type of activity. Reactions and attempts to maintain balance are common whenever the center of gravity of the body is displaced over any base of support. When centered on the Balance Trainer, this displacement is ever present as the properties of the dome provide a dynamic surface that continually attempts to displace the body's center of gravity.
balance training research
An irony of past balance research is that researchers have found it difficult to measure or show balance improvements in individuals who have “normal” balance. However, that does not mean that improvements do not occur. Limited research has been performed on unstable surfaces with healthy or highly conditioned athletes. Data (Behm et al. 2003, 2005) suggest that trunk stabilizer muscles are activated to a greater degree by unstable versus stable exercises and that unilateral resistance exercises cause greater muscle activity in the contra-lateral (opposite) side trunk stabilizers. Exercises that include an overhead shoulder press while seated on a stability ball and squat exercises performed on progressively more unstable surfaces, have demonstrated this increased muscle activation (Anderson and Behm 2005). Both McGill (2001, 2002, 2004) and Vera-Garcia showed increased muscle activity on an unstable surface when compared to a stable surface. It is important to remember that the goal of training on unstable surfaces is to increase muscle activity without necessarily increasing load.
balance research and the older adult
Balance research has historically focused on older adult populations because this group is at an increased risk for fall related fractures. Because proprioceptive feedback capability is often reduce in active or diseased older adult populations, this group can show marked improvement in both balance and physical improvement even with non-specific, or nonbalance focused conditioning approaches. Research also shows that specific strength and/or balance exercises enhance stability and reduce the risk of falling, as well as increase overall physical performance (LaStayo et al. 2003; Spirduso 1995; Judge et al. 1993).
balance research in rehabilitation and injury prevention programs
Significant research has focused on injured and disabled populations. Restoring (rehabilitating) or maintaining (prevention) proprioception allows the body to maintain stability and body orientation during static and dynamic activities. During rehabilitation, proprioceptive programs are specifically tailored to each patient, and as is true for any functional rehabilitation program, should include balance training, closed kinetic chain exercise (CCE) like leg presses, single leg balance, hops or jumps, back strengthening exercise and quadruped stabilization (i.e., position on the hands and knees or “all-fours” to stabilize the scapulae in a closed-kinetic chain position), as well as sport specific training and drills (Carmeli et al. 2003; McCurday and Conner 2003; Gauchard et al. 1993; Judge et al. 1993; Laskowski et al. 1997).
It is believed that impaired “joint position sense,” when overlooked in a rehabilitation program, may be a leading cause for recurrent injuries. On the other hand, proprioceptive and balance training have been shown to significantly reduce the incidence of anterior cruciate ligament (ACL) injury in soccer players (reported in Laskowski et al. 1997, pg. 97). The goal of proprioceptive training during rehabilitation is to maximize protection from injury and restore one hundred percent, or optimal, function (Laskowski et al. 1997). From this perspective, it would make perfect sense that this type of functional and balance training would be a necessary part of any training or rehabilitation program, and be appropriate for all types of people, regardless of program goals.
Rehabilitation and injury prevention oriented programs can be designed to challenge, enhance and improve the proprioceptive system. By affecting (training) various central nervous system pathways and reflex arcs, “prophylactic” (protective) proprioception training programs may protect against injury (Caraffa et al. reported in Laskowski et al. 1997).
static and dynamic joint stability
A major category of proprioceptive or functional training is balance training. An example of training the proprioceptive system and joint stability in a mostly static way includes one-legged standing balance exercises. The ability of appropriately activated muscles to stabilize a joint during more complex movement defines dynamic joint stability (Laskowski 1997, pg. 98). Progressive and dynamic challenges, for example, hopping from one Balance Trainer dome to another on one leg, jumping vertically and landing on the dome or performing push-ups on the platform side of the Balance Trainer while simultaneously keeping the platform level, changes the nature of the required joint stability to
functional training controversy:
science vs. science?
It seems that “two sides” have evolved with regard to whether or not functional training can have an impact on performance. Experts on both sides are in agreement that proprioceptive training is valuable to rehabilitation. Research that is ongoing will soon point to additional training benefits that go beyond what has been discussed in this text. As mentioned, the difficulty as it relates to objective test data, is for researchers to figure out how to measure balance improvements with people who have normal balance capability (Brown, ed. 2002, 2005; Willardson 2004).
How can two sides, which both base their claim on science, be at such odds? Many of the issues will come down to semantics and how we define training result as it relates to performance. This topic will be greatly affected by current testing methods and interest in this type of training. Fitness professionals and consumers are trying to sort through the seemingly contradictory information and it is placing a burden on the scientific community to provide answers and guidelines with regard to what this type of training can and cannot accomplish. This scenario will accelerate research and learning.
Ultimately, for an understanding of the subject to move forward, “both sides” will have to move from all or none positions and identify the value of traditional approaches to training, as well as functional and integrated movement approaches. This would allow and encourage future research to define the possibilities of functional training and its impact on performance improvement (Brown, ed. 2002, 2005; Willardson 2004; IDEA 2003).
It is obvious that functional or proprioceptive training programs work. Functional and balance training teaching methodology should be built on an understanding of the “why, when and how” behind exercise choice, implementation and progression. Rather than taking a haphazard approach to designing functional training programs, or not fully understanding why this type of training is being offered, it is therefore important to identify what is being accomplished with functional training workouts. It is also important to understand why and how functional training dovetails with, and complements other science-based aspects of a general fitness and performance training hierarchy.
Strategies for balance training focus on increasing sensory input in a variety of training environments with different proprioceptive challenges (visual affect, contact points, movement and external stimulus). Ultimately, training like this will improve motor skills, kinesthetic awareness and balance. The BOSU Complete Workout System takes you through this exciting and productive process step-by-step.