1. OVERVIEW AND DESCRIPTION
Balance, also known as postural control, is the ability to maintain, attain, or correct the center of mass in relation to the base of support1 and it is necessary for successful daily life tasks. Maintaining normal balance requires multiple systems (somatosensory, vestibular, visual, musculoskeletal system, and cognition) working in integrative fashion, and the disorders affecting one or more of these systems may lead to impaired balance. With aging, even normal individuals show increased truncal sway and reduced postural control due to change in the individual system as well as central ability to integrate these systems (e.g. attention, reaction time) to work effectively.
Balance is maintained through a complex process involving sensory detection of body motions, integration of sensorimotor information within the central nervous system, and execution of appropriate musculoskeletal responses.
Contributing Factors for Balance Impairment are
- Decreased peripheral sensation (e.g. somatosensory inputs from ankle joints)
- Muscle weakness (e.g. hip abductor, knee extensor/flexor, ankle dorsiflexors)
- Limited range of motion of lower limb joints (e.g. ankle eversion)
- Poor sensory input (visual acuity, reduced vestibular function)
- Pain syndrome
- Fear of falling
- Reduced central integrative processing and cognitive ability (e.g. executive function)
- Specific neurological (central and peripheral) and musculoskeletal disorders
- CNS disorders: Stroke, Parkinson’s disease, cervical myelopathy, hydrocephalus, vitamin B12 deficiency, cerebellar degeneration
- PNS disorders: polyradiculopathy, ganglionopathy, peripheral neuropathy, myopathy
- musculoskeletal conditions (e.g. knee instability from osteoarthritis, painful foot conditions)
- Extrinsic factors
- Poor footwear (too high or too low heeled shoes)
- Environmental factors (uneven terrain, slippery surface, barriers).
Lower limb muscle power (force x velocity of shortening) seems to be more important than muscle strength correlating with balance deficit. It is hypothesized that when threat to balance (narrowed base of support, perturbation, loss of vision or proprioception) occurs, rapid responses must be engaged to maintain postural stability.2 The velocity at which high muscular forces can be generated may be the critical determinants to maintain balance and prevent a fall.2 Ankle range of motion particularly ankle eversion declines with aging and is associated with reduced postural control.3 Central integrative processing or the ability for a person to process the information for appropriate response is a key aspect of postural control mechanism. In older adults, reaction time in the presence of conflicting sensory inputs is prolonged. There has been increasing evidence that higher level brain function, particularly executive cognitive function is required for optimal balance.4 Balance is often impaired during dual task situations particularly in older adults, which might be explained by the divided attention between maintaining balance and performing secondary tasks. Psychological distress including fear of falling is also associated with reduced balance in patients with various neurological disorders.5,6
2. RELEVANCE TO CLINICAL PRACTICE
A study based on the National Health Interview Survey (NHIS) showed that approximately one in five older individuals in the United States reported balance problems with higher prevalence in women compared to men.7 Notably, more than 20% of patients with balance problems reported that their symptoms are triggered by medications (18.7% by prescription medications, 1.7% by over the counter medications). Balance impairment is more than 2.5 times more prevalent among older individuals with pain.8 Falls are well recognized as the most significant consequences of balance impairment. In addition to falls, nearly 30% of elderly with balance problems reported that poor balance prevents them from participating in activities (61% in exercise, 46% in social events, 47% in driving, 38% in work). More importantly, one in four of those with balance impairment had difficulty in activities of daily living (ADLs).7 Literature showed that various exercise interventions (e.g. Tai Chi) can improve balance and potentially reduce the risk of the falls in older individuals and individuals with various disabilities. Balance exercises, thus, improves quality of life, socialization and associated morbidity/mortality.
3. CLINICAL AND LABORATORY ASSESSMENT
History taking should include self -perceived balance impairment and falls. History taking can be framed for both patient’s complaints of specific system issues (e.g. foot pain) and description of overall balance impairment (feeling unsteady). Clinicians should pay attention to associated symptoms (e.g. bradykinesia, spasticity, back pain) to identify underlying conditions associated with balance impairment:
- Acute and chronic medical problems (recent illness, surgery, hospitalization)
- Medications history including number of medications, new medications, over the counter medications and any dosing adjustment
- Fall history including circumstances and symptoms (if yes – functional balance test indicated)
- Fear of falling
- Mental Health assessment (e.g. depression, delirium, dementia)
- Functional history (use of assistive device, personal assistance)
- Home environment, including railing on staircase, door width, floor surface (area rugs), grab bars in the bathroom and shower, equipment (shower chair, etc.)
- Social History of alcohol use, illegal drug use, smoking, other supplements
- Cardiovascular history (arrhythmia, murmurs)
Clinicians should focus on:
- Vitals, including orthostatic blood pressure and heart rate
- Neurologic examination
- Cognitive function (e.g. Mini Mental Status Examination, Montreal Cognitive Assessment Test)
- Cranial nerves, Sensation (proprioception/vibration), Motor (upper/lower limb and trunk), reflexes, muscle strength, tone, coordination and Cerebellar function.
- Visual acuity including visual field testing as appropriate
- Hearing & vestibular function (if applicable)
- Musculoskeletal examination
- Standing posture for kyphosis of spine, loss of lumbar lordosis
- Range of motion of hips, knees, ankle, and foot (tightness of hip flexors, knee flexors, and gastrocnemius muscles)
- Joint swelling and any deformity or instability.
- Looking for excessive worn out pattern on the sole that may threaten stable base of support, Appropriate heel height,
- Relatively thin sole is better for the balance than excessively thick cushioned sole
- Evaluation of gait mechanics
- Slow gait speed, base of support (wide based), short step/stride length, reduced cadence, increased double support time
- Reduced ability to tandem walk
- Need for any assistance for gait.
Clinical Balance Assessment
Clinical measurement tools for balance are used to quantify the functional capacity of the sum of multiple systems that enable postural stability. They are often used as screening tools to identify individuals at elevated risk for falls requiring further evaluation. However, the value of balance assessment in discriminating fallers from non-fallers is somewhat limited since fall is multifactorial condition. The norms, cutoff scores for fall risk, sensitivity and specificity of each tool varies depending on the cutoff scores and population tested.1,9
4. SUMMARY OF CLINICAL BALANCE TESTS
|Simple Balance Tests (Readily tested in the clinic)|
|Balance Test||Procedure||Mean Value (range)||Cutoff/|
|Sensitivity, Specificity for fall prediction||Pros||Cons|
|Functional Reach Test10|
|Individual is asked to reach forward farther than arm’s length without changing the base of support in standing,|
1-2 minutes to complete.
|13.2”: older M|
10.5”: older F living in community
Predicting falls in older adults
|73%/88.5%, others report inconsistent results||Can be done in a small room||Only assessing static balance|
|Short Physical Performance Battery (SPPB)11||Balance, Gait Speed, Chair Stand Tests|
Measures lower extremity function
Score range 0-12 (higher score is better balance)
|11-12: healthy elderly|
10: 4x risk for mobility disability
|Risk of falls in older adults|
|81%/52% for frailty in older adults12||Separate component of mobility can be tested.||Space to perform walking (4m)|
|Timed Up and Go test (TUG)13|
|Individual stands up from an arm chair, walks a distance of 3 m, turns, walks back, and sits down again in the chair (higher score indicating worse balance)||7-11: older M|
7-12: older F living in community
|>13.5 sec in older adults for fall risk||87%/87% for falls in older adults14||Dynamic balance||Space to perform TUG|
|Detailed Balance Test|
|Berg Balance Scale15||14 items with each item scoring from 0 to 4 (total score range 0-56), higher score indicating better balance)||50-55 for living in community||<45-49: high risk for falls||53%/96% for falls in older adults||High specificity|
|>15-20 min to perform, low sensitivity for fall prediction|
|Performance Oriented Mobility Assessment (POMA) Scale by Tinetti16||Total score range 0-28 (higher score is better balance), consisting of|
|25-27: 65-79 of age||<19: high risk of falling|
|No better than the simple test in discriminating fallers||Time consuming|
(15 min to complete)
Instrumental Balance Assessment
Instrumental balance assessments (e.g. posturography) may have a role in understanding pathophysiology of balance disorders and evaluating the response to intervention, however, they may have limited role in predicting risk of falling in patients.17
|Instrumental Balance Test||Description, Advantage, Disadvantages|
|Computerized Dynamic Posturography (CDP)|
|Posturography utilizing force plates18|
|Trunk sway measured by Angular Velocity Sensors (AVS)19|
Laboratory workup and imaging studies
Based on the clinical evaluation, further work-up should be initiated as needed.
For patients with suspected central nervous system (stroke, myelopathy), brain and/or spinal cord (cervical/thoracic spine) imaging is recommended. If peripheral neuropathy is suspected, the full work-up for neuropathy including vitamin B12, hemoglobin A1C, thyroid function test (e.g. thyroid stimulating hormone), serum protein electrophoresis, and electrodiagnosis can be performed. In patients without a clear diagnosis a complete blood count and a comprehensive metabolic panel should also be considered. Lower limb joint instability and pain may require imaging studies.
5. TREATMENT STRATEGIES
Treatment starts with identification of modifiable risk factors for balance problems. Physiatrists will play a critical role in setting realistic goals of intervention and rehabilitation plan to achieve them. Clinicians should focus on patient education about the causes and potential implications of balance impairment and rationale for treatment options including exercise program and home modifications for reduction of anxiety and enhancing compliance.
Specific strategies are
- Review modifiable risk factors for falls and address them (see the risk factors in the table above, Please see the Fall Prevention chapter as well)
- Explore the patients’ perceptions of the causes of balance impairments (and falls) and willingness to make changes to reduce the risk of falls. Approaches facilitating behavior change: providing choices, personalizing options, and focusing strategies on enhancing quality of life.
- Careful review of medications (including over the counter) considering 20% of unsteadiness in older adults may have pharmacologic etiology, may reveal medications triggering the unsteadiness
- Pain medications, antispasticity, psychoactive medications-antidepressant, anxiolytic medications
- Being sensitive about emotional distress of older patients with balance impairment related to falls, potential loss of independence, and further deterioration of conditions.
- Use of ambulatory aids is often associated with the perception of being “old and disabled”. Therefore, prescription of ambulatory aids should be one after discussing with the patients the need for these devices, how they can help with their balance, the potential plan to wean off the devices, and their willingness to use these aids.
- Discuss the importance of strength and balance exercise (Stretching, walking have not been shown to reduce falls).
- To improve balance, balance exercises should be moderate to high challenge and progress in difficulty, minimum of 2 hours per week for 25 weeks. Assist patients to find a place where they can engage in this type of exercise (PT, community programs, home programs)20
- Strengthening exercise, three dimensional exercise (Tai Chi, qi gong, dance, yoga)
- Vitamin D 800 IU per day for those at risk of fall and suspected vitamin D deficiency.
- Offer ongoing monitoring and follow-up
Impact of balance training
Balance training improved balance as measured by the Berg Balance Scale and quantitative postural sway, resulting in a significant reduction in the rate of falls in older adults. Recent Cochrane review reported that exercise programs involving gait, balance, coordination, and functional exercises decrease the rate of falls. Strengthening exercise, three dimensional exercise (Tai Chi, qi gong, dance, yoga), and combination of these exercises all appear to improve balance quantifiably.21 However, there is insufficient evidence on the effects of general physical activity (e.g. walking, cycling), and exercise involving computerized balance program, or vibration plates on balance.21
6. CUTTING EDGE/UNIQUE CONCEPTS/EMERGING ISSUES
As balance impairment has been recognized as an important public health issue in US healthcare system, there is a growing interest from private companies to build supportive tools for patients with balance impairment (ambulatory monitoring device, high tech glasses enhancing foot placement, virtual reality). For specific disease population (Parkinson’s disease), trials of neurosurgical tools (e.g. subthalamic or pallidal deep brain stimulation) are ongoing for balance improvement.22
7. GAPS IN KNOWLEDGE/EVIDENCE
The major pitfalls in the literature and clinical practice in management of balance impairment include lumping balance disabilities despite the different pathophysiology, failure of enhancing compensatory mechanisms, and failure to sustain effective exercise interventions. Implementation and Dissemination of currently available findings about balance assessment and intervention is greatly needed, including the transition of care from the hospital or clinic to the community.
- Noohu MM, Aparajit BD, H. ME. Relevance of balance measurement tools and balance training for fall prevention in older adults. Journal of Clinical Gerontology & Geriatrics 2014;5:31-35.
- Orr R, de Vos NJ, Singh NA, Ross DA, Stavrinos TM, Fiatarone-Singh MA. Power training improves balance in healthy older adults. J Gerontol A Biol Sci Med Sci 2006;61:78-85.
- Bok SK, Lee TH, Lee SS. The effects of changes of ankle strength and range of motion according to aging on balance. Ann Rehabil Med 2013;37:10-16.
- van Iersel MB, Kessels RP, Bloem BR, Verbeek AL, Olde Rikkert MG. Executive functions are associated with gait and balance in community-living elderly people. J Gerontol A Biol Sci Med Sci 2008;63:1344-1349.
- Bryant MS, Rintala DH, Hou JG, Protas EJ. Influence of fear of falling on gait and balance in Parkinson’s disease. Disabil Rehabil 2014;36:744-748.
- Schinkel-Ivy A, Inness EL, Mansfield A. Relationships between fear of falling, balance confidence, and control of balance, gait, and reactive stepping in individuals with sub-acute stroke. Gait Posture 2015.
- Lin HW, Bhattacharyya N. Balance disorders in the elderly: epidemiology and functional impact. Laryngoscope 2012;122:1858-1861.
- Patel KV, Phelan EA, Leveille SG, Lamb SE, Missikpode C, Wallace RB, Guralnik JM, Turk DC. High prevalence of falls, fear of falling, and impaired balance in older adults with pain in the United States: findings from the 2011 National Health and Aging Trends Study. J Am Geriatr Soc 2014;62:1844-1852.
- Jernigan SD, Pohl PS, Mahnken JD, Kluding PM. Diagnostic accuracy of fall risk assessment tools in people with diabetic peripheral neuropathy. Phys Ther 2012;92:1461-1470.
- Gates S, Smith LA, Fisher JD, Lamb SE. Systematic review of accuracy of screening instruments for predicting fall risk among independently living older adults. J Rehabil Res Dev 2008;45:1105-1116.
- Vasunilashorn S, Coppin AK, Patel KV, Lauretani F, Ferrucci L, Bandinelli S, Guralnik JM. Use of the Short Physical Performance Battery Score to predict loss of ability to walk 400 meters: analysis from the InCHIANTI study. J Gerontol A Biol Sci Med Sci 2009;64:223-229.
- da Camara SM, Alvarado BE, Guralnik JM, Guerra RO, Maciel AC. Using the Short Physical Performance Battery to screen for frailty in young-old adults with distinct socioeconomic conditions. Geriatr Gerontol Int 2013;13:421-428.
- Barry E, Galvin R, Keogh C, Horgan F, Fahey T. Is the Timed Up and Go test a useful predictor of risk of falls in community dwelling older adults: a systematic review and meta-analysis. BMC Geriatr 2014;14:14.
- Shumway-Cook A, Brauer S, Woollacott M. Predicting the probability for falls in community-dwelling older adults using the Timed Up & Go Test. Phys Ther 2000;80:896-903.
- Muir SW, Berg K, Chesworth B, Speechley M. Use of the Berg Balance Scale for predicting multiple falls in community-dwelling elderly people: a prospective study. Phys Ther 2008;88:449-459.
- Faber MJ, Bosscher RJ, van Wieringen PC. Clinimetric properties of the performance-oriented mobility assessment. Phys Ther 2006;86:944-954.
- Nardone A, Schieppati M. The role of instrumental assessment of balance in clinical decision making. Eur J Phys Rehabil Med 2010;46:221-237.
- Sawacha Z, Carraro E, Contessa P, Guiotto A, Masiero S, Cobelli C. Relationship between clinical and instrumental balance assessments in chronic post-stroke hemiparesis subjects. J Neuroeng Rehabil 2013;10:95.
- Whitney SL, Roche JL, Marchetti GF, Lin CC, Steed DP, Furman GR, Musolino MC, Redfern MS. A comparison of accelerometry and center of pressure measures during computerized dynamic posturography: a measure of balance. Gait Posture 2011;33:594-599.
- Sherrington C, Whitney JC, Lord SR, Herbert RD, Cumming RG, Close JC. Effective exercise for the prevention of falls: a systematic review and meta-analysis. J Am Geriatr Soc 2008;56:2234-2243.
- Howe TE, Rochester L, Neil F, Skelton DA, Ballinger C. Exercise for improving balance in older people. Cochrane Database Syst Rev 2011:CD004963.
- Maetzler W, Nieuwhof F, Hasmann SE, Bloem BR. Emerging therapies for gait disability and balance impairment: promises and pitfalls. Mov Disord 2013;28:1576-1586.
Mooyeon Oh-Park, MD
Nothing to Disclose
Natasha Mehta, MD
Nothing to Disclose