Jan Schroeder, Ph.D by Jan Schroeder, Ph.D
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In daily life, adequate postural control is needed to safely manage activities of daily living (e.g., walking or climbing the stairs without sustaining a fall). The ability to effectively perform balance activities throughout the lifespan is important for health as well as activity-related components of everyday life. Individuals who experience deficits in balance performance increase their risk of falling and sustaining an injury. Therefore, training for improved balance performance becomes a critical piece of exercise programming. The question becomes: Should we train balance in older adults the same way that we train younger adults?

Balance performance encompasses both static conditions in which the base of support, such as the feet, and the ground remain stationary, as well as dynamic conditions in which both the base of support and the center of mass shift. Balance can be further subdivided to include static steady state balance, dynamic steady state balance, proactive balance (also called anticipatory balance) and reactive balance (see Table 1 for definitions).

As we age, certain physiological systems begin to decline, which can greatly influence the ability to maintain adequate postural control or balance. Age-related declines in the vestibular (inner ear), visual, somatosensory, musculoskeletal and central nervous system, as well as orthopedic issues and cognitive impairments, all contribute to a deterioration in balance (da Silva Borges et al., 2014; Lord et al., 1994). As a result, older adults may begin to show impairments in balance and stability, which increases the risk of falling during both static and dynamic conditions.

The ability to maintain balance and effectively perform activities of daily living is dependent upon the person’s ability to effectively regulate the relationship between the body’s center of mass and the base of support. The postural control system has to integrate the sensory information on body sway and activate the muscles appropriately in terms of order and intensity.

Let’s look at how younger adults and older adults differ in the way they try to maintain balance. In steady-state balance, such as quiet standing, compared to young adults, older adults activate up to three times more muscle to maintain their balance (Laughton et al., 2003). It is suggested that weakness in the leg muscles, particularly the tibialis anterior and the vastus lateralis, may impair the ability to correct a shift in the body’s center of gravity. An older adult may need to maintain these leg muscles in an activated state to provide additional stability with increased muscle weakness. Strengthening the muscles of the leg may help an older adult correct shifts in the body’s center of gravity.

If we look at dynamic steady-state balance, such as stepping activities, we also see differences in the way that younger and older adults maintain balance. When an external perturbation occurs, such as a slip, a common strategy to use is a step, either as an anterior-posterior or medial-lateral movement. In anterior-posterior movements, older adults tend to adopt similar recovery strategies as younger adults, but they take significantly more time to execute the step strategy, which can result in a fall (Porter and Nantel, 2015). In a medial-lateral movement, older adults tend to take a step forward prior to a medial-lateral direction, which can compromise the ability to recover and may result in a lateral fall (Porter and Nantel, 2015). In addition, older adults tend to move the arms and grasp safety handrails more frequently than younger adults and are more likely to experience a collision between the swing foot and the stance limb during a medial-lateral disturbance in balance (Maki et al., 2000). The lack of lateral stability may cause the older adult to fall to the side, which may lead to a debilitating hip fracture. As we age, we also tend to take more steps to recover our equilibrium from a lateral step than we did when we were younger.

And finally, we can look at anticipatory and reactive balance strategies. Older adults tend to rely more on reactive balance strategies than proactive strategies, meaning they tend to wait to react to a disturbance in balance compared to a younger adult who anticipates a disturbance and makes the appropriate adjustments to maintain balance (Paxton et al., 2008).

While static, dynamic, proactive and reactive balance require the integration and coordination of the same systems, each places a different demand on the control systems. For example, during static stance (i.e., standing still) the body’s center of mass moves slowly with small sways created by small external forces acting on the body. During dynamic activities, however, greater external forces are present and more variations in the environment occur, which place higher demands on all balance control systems (Hrysomallis et al., 2006; Winter et al., 1996).

Therefore, multiple exercises that provoke dynamic/static, steady state, proactive and reactive types of balance should be used during training to target each balance dimension individually. Older adults may need to perform additional activities in the frontal plane to promote stability with a medial-lateral disturbance. See Table 2 for suggested activities for each type of balance.

Table 1: Definition of Types of Balance

Term

Definition

Example

Static steady-state balance

Maintaining a steady position while stationary

Maintaining balance while sitting or standing

Dynamic steady-state balance

Maintaining a steady position while moving

Maintaining balance while walking

Proactive balance

Anticipation of a predicted postural disturbance

Maintaining balance while reaching up to a shelf

Reactive balance

Compensation of unpredicted postural disturbance

Maintaining balance after slipping on a wet floor

Table 2: Sample Activities for Different Types of Balance

Balance Component

Sample Activities

Static steady-state balance

Standing with changes in base of support (feet shoulder-width apart; narrow stance; staggered stance; single-leg stance)

Dynamic steady-state balance

Walking with changes in base of support (feet shoulder-width apart; semi-tandem; heel to toe); lateral stepping

Proactive balance

Ball catch with changes in base of support; obstacle courses

Reactive balance

Unanticipated nudge; use of foam pads

 

 

References

da Silva Borges, E.G. et al. (2014). Postural balance and falls in elderly nursing home residents enrolled in a ballroom dancing program. Archives of Gerontology and Geriatrics, 59, 2, 312–316.

Hrysomallis, C. et al. (2006). Relationship between static and dynamic balance tests among elite Australian footballers. Journal of Science and Medicine in Sport, 9, 4, 288–291.

Laughton, C.A. et al. (2003). Aging, muscle activity and balance control: Physiological changes associated with balance impairment. Gait and Posture. 18, 101-108.

Lord, S.R. et al. (1994). Physiological factors associated with falls in older community-dwelling women. Journal of the American Geriatrics Society, 42, 10, 1110–1117.

Maki, B.E. et al. (2000). Age-related differences in laterally directed compensatory stepping behavior. The Journals of Gerontology Series, Biological Sciences and Medical Sciences, 55, M270-M277

Paxton, J. et al. (2008). Cognitive control, goal maintenance, and prefrontal function in healthy aging. Cerebral Cortex, 18, 1010–1028.

Porter, S. and Nantel, J. (2015). Older adults prioritize postural stability in the anterior-posterior direction to regain balance following a volitional lateral step. Gait and Posture, 41, 666-669.

Winter, D.A. et al. (1996). Unified theory regarding A/P and M/L balance in quiet stance. Journal of Neurophysiology, 75, 6, 2334–2343

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