Traditionally, fitness professionals design programming and deploy measures to improve elemental fitness qualities, such as strength, muscular endurance, flexibility, and aerobic capacity, giving little if any thought to balance training.
At the dawn of the millennium, “functional training” was all the rage in the fitness industry. Everyone from mainstream pundits to esteemed strength and conditioning coaches extolled the seemingly interminable scroll of benefits functional training.
During that time, functional training struck a razor edge balance between contrarian and charlatanistic — it deviated from conventional resistance training which until that point, comprised almost exclusively of free weights and machines — and introduced a bevy of accessories that were purported to provide a safer alternative while improving balance and stability. Further, some disillusioned and somewhat naïve coaches advocated for performing sport-specific movements while using accessories consisting of elastic bands and tubing, wobble boards, physioballs, and hemispheric domes.
While their efforts were well-intentioned, they were largely misguided. Force production capabilities are greatly diminished when performing exercises on an unstable surface. And with elasticized resistance, it can be challenging to match strength curves associated with sporting movements — most movement in sport has an ascending strength curve, meaning when leverage is gained throughout the range of motion, less force is required. Elasticized resistance has a descending strength curve, meaning more force is required as leverage is gained due to change in tensile properties of the band or tubing (loss of slack and added tension). Sure, elasticized resistance can be added to accommodate the strength curve (i.e., help a powerlifter near lockout on a given lift), but that’s another entire article.
Exploring the Underpinnings of Balance
In order to train for balance, we need to understand sensorimotor function and the ternion of systems which influence it — visual system, proprioceptive system, and vestibular system.
According to Shumway-Cook and Woollacott (2007), sensorimotor function encompasses all sensory and motor elements necessary for an individual to interact with their environment (5), more specifically afferent (feed-forward), efferent (feedback) signaling, processing, and integration components of the brain stem and the muscles to whom and from, neural communications are exchanged.
The visual system captures and processes light through refraction, a process through which light rays are manipulated and projected onto the retina to form the images, such as the text of this very sentence. Disruptions in refractions can manifest as blurred vision, nearsightedness, farsightedness, and astigmatism.
The proprioceptive system is adorned with mechanosensory neurons spanning our body’s musculoskeletal system that are divided into four key groups and their respective primary transmitting functions —: Golgi tendon organs(GTOs) — change in muscle tension, muscle spindles — change in muscle length, Ruffini endings — sensations of stretch, warmth, and deformation within joint capsules, and Ruffini corpuscles — sensations of pressure and vibration. Information from these mechanoreceptors is transmitted via afferent signals to the brain stem of the central nervous system which rapidly interprets and processes information to deploy a response of muscles via efferent signals at speeds of 70-120 meters per second or the speed of a redlining Bugatti Veyron ripping through the Bonneville Salt Flats.
The vestibular system consists of a bundle of structures found embedded within the inner ear including three semicircular canals that are sensitive to head movement in the transverse plane and two otolith organs that are sensitive to head movement in the sagittal plane. Sudden or unanticipated head movement can perturbate the vestibular bundle causing dizziness or temporary disorientation. When the head moves, the vestibular system transmits information to the visual system engaging an involuntary response known as vestibulo-ocular reflex, which stabilizes gaze. Try it for yourself: Re-read the last sentence and turn your head to the right, the eyes will move to the left or turn your head to the left and you’ll discover the eyes move to the right. The eyes seemingly default to an axis of rotation due to this phenomenon.
Putting it all Together
Standing is a task that many of us take for granted. To achieve and sustain a standing position requires an almost seamless interplay of the abovementioned systems that influence sensorimotor function that collectively capture and transmit information to the central nervous system which relays messages that induce reflexive activation of local stabilizer muscles which regulate the positioning and centration of passive restraints (i.e., non-contractile elements such as bones, joints and the crossing or attaching ligaments).
To achieve and sustain balance is a much more challenging and energetically demanding task that requires the activation of global mobilizer muscles or agonists and synergists, such as the muscles of the hip flexors, quadriceps, and calves that initiate gait via near simultaneous hip, knee, and dorsi- flexion. Continuous dynamic stabilization of global stabilizer muscles (i.e., rectus abdominus and erector spinae) and local stabilizer muscles (i.e., quadratus lumborum, multifidi, rotares, transversus abdominus) are also required to uphold locomotion. As greater gait speeds are achieved the activation of global mobilizers and dynamic stabilization demands of the global and local stabilizer muscles intensifies.
What do an offensive lineman, a person doing yardwork, and an elderly person have in common? A perpetual need to maintain balance.
For an offensive lineman, maintaining balance might help them ward off the bullrush of a hard-charging outside linebacker salivating over the quarterback’s nameplate — serving as the demarcation between a pulverizing sack or a successful conversion.
For the person doing yardwork, maintaining balance as they navigate the mulch bed enveloping the perimeter of their home with potters in tow could mean the difference between making their neighbors envious of their green thumb or their neighbors taking them to the ER with a broken thumb among other fractures.
And for the elderly, whose balance diminishes beyond the age of 60 (1) as the collective result of decrements in visual, proprioceptive, and vestibular system functioning, improving it could prolong their independence and quality of life as they age.
In each scenario, to avoid succumbing to a devastating fall that could impact the outcome of a competition or health, their center of gravity (BOS) must fall within their base of support (BOS).
Establishing and maintaining a base of support (BOS) that accommodates your center of gravity (COG) requires sufficient dynamic and isometric strength. Muscular force demands are multiplied when velocity is increased (i.e., running > walking), external loading is added (i.e., lifting weights or grocery bags), or the body has external forces acting upon it as in competitive sports.
Balance Training Considerations
Though it may seem convenient and less obtrusive to tap a niche balance training modality or rely on a functional training accessory, force production and muscle activation was lessened amid unstable training environments versus stable conditions (2). A randomized control study entailing the execution of leg extension and leg curl exercises with incremental progressive overload over a 12-week period drew significant improvements in strength, step test performance, and balance measurements among elderly men and women aged 72.4±3.4 (4). And while unstable training environments have demonstrated benefits, with unstable surface training with free weights evoking similar results in strength, power, and balance with training on stable surfaces conducted twice weekly over a 10-week period (3), it is worth noting that these sessions were apart of a supervised study and training in this manner can impede sufficient external loading that is requisite to stimulate an osteogenic or hypertrophic response, which among elderly persons, are sorely needed to optimize metabolic and musculoskeletal function.
Performing off-loaded or unilateral exercises are a more economical and efficient means to activate local stabilizer muscles intimately involved in balance. Unilateral carries, presses, rows and one-legged deadlift and squat variations have been shown to activate contralateral (opposite side) and ipsilateral (same side) stabilizer muscles sans the need for elaborate contraptions and set-up requirements of functional training accessories and surfaces.
Prescribing exercises to improve posture such as those exhibiting maladaptive forward head posture, excessive kyphosis (thoracic convexity) or lordosis (lumbar concavity) will also contribute to improving static balance that will set the foundation for fluid and pain-free dynamic movements ranging from walking and progressing to faster gait speeds.
A modern-day interpretation of functional training is to restore and uphold function, not malign function with gimmicky training exercises and accessories. Balance, like strength, and muscular endurance, can be achieved through resistance training that employs incremental progressive overload, incorporates appropriate variety while mitigating risk.
- Abrahamova, D. & Hlavacka, F. (2008). Age-related changes of human balance during quiet stance. Physiological Research, 57, 957-964.
- Behm, D., Anderson, K., & Curnew, S. (2002). Muscle force and neuromuscular activation under stable and unstable conditions. Journal of Strength and Conditioning Research, 16 (3), 416-422.
- Eckardt, N. (2016). Lower-extremity resistance training on unstable surfaces improves proxies of muscle strength, power, and balance in health older adults: a randomized control trial. BMC Geriatrics, 16, 191.
- Lee, I. & Park, S. (2013). Balance improvement by strength training for the elderly. Journal of Physical Therapy Science, 25 (12), 1591-1593.
- Shumway-Cook, A., & Woollacott, M.H. (2007). Motor control: Translating research into clinical practice. Philadelphia: Lippincott Williams & Wilkins.