Introduction to STABLE

Specific Training According to BaLance Evaluation (STABLE) is an genuine approach to measure individual balance abilities, focus exercises towards specific limitations and monitor change.

Prescribing exercises in STABLE, three principal factors must be taken into consideration: 

  • The patients´ history and personal preferences
  • The patients´ Impairments of body structures and functions
  • The patients´ abilities within six domains of balance

STABLE graphics

History and personal preferences

The patients´ history and personal preferences should be considered because each patient may have good or bad experiences with exercising or with specific exercises or physical activity in general. Further, the patient can report specific challenging or symptom provoking activities, contexts or movements which might not become evident in the physical examination, but nevertheless should be addressed in the treatment.

Impairments of body structures and functions

Limitations in physical function can be a consequence of various impairments of body structures, which often interact. To improve functional limitations it can be necessary to target specific impairments of body structures with specific exercises or other interventions. E.g. limitations in reaching out over ones base of support can be caused by vestibular impairment or neuropathy in lower extremities and can be improved with exercises designed to improve stability limits, but if the patient has severe low back pain or impaired range of motion in any joint involved in the reaching task, first priority might be exercises or other interventions to improve local joint range of motion and diminish the pain.

Abilities within six domains of balance

Quantifying the patients´ relative abilities within six domains of balance is a core property in STABLE. Six clinical measures are applied to measure the six domains of balance: 

  • The "adjusted sit to stand test (ASTS)" is applied to measure "power"
  • The "maximum reach test is (mReach)" is applied to measure "stability limits"
  • The "turn and touch test (TAT)" is applied to measure "anticipatory turning"
  • The "reactive four square step test (RFSST)" is applied to measure "reactive stepping"
  • The "test of reference frame interaction in balance (TRIB)" is applied to measure "sensory orientation"
  • The "cognitive timed up and go (CTUG)" is applied to measure "cognitive-motor interaction"

The score of each measure quantifies the patients´ balance ability within the target domain. By plotting the scores relative to the normative score of each measure a personal balance profile is produced. This profile shows:

  • How is the patients´ ability within each balance domain (i.e. how "good" or "bad" does the patient perform within each domain relative to other patients)
  • How is the the patients´ "overall" balance ability (i.e. how "good" or "bad" does the patient perform in all domains overall)
  • How is the patients´ relative abilities between the six domains (i.e. in which domain(s) does the patient perform "worse" and does the patient perform relatively better in some domain(s)) 

The overarching premise of STABLE is that exercises are prescribed to target the most compromised balance domain(s), because this/these domain(s) are “the weakest link in the chain” and eventually define the patients´ overall balance ability.

In some situations, though, it can be preferred to choose a different focus when prescribing exercises. There are two primary exemptions from targeting the most compromised domain:

  1. The difference between the scores is negligible:

The scale in the online balance profile calculator adjusts automatically according to the plotted scores. Thus, differences between scores can appear graphically as momentous although the clinical importance of the differences is dubious. We recommend only applying the balance profile as the primary clinical guidance if the difference between the most compromised domain and the average z-score is minimum z>0.5.

If for instance the balance profile of a patient shows that turning has the lowest z-score, but the difference between the z-scores of turning and the average z-scores is less than 0.5, then the balance profile is attributed with less importance and the focus domain is chosen based on the patients´ history, physical examination and personal preferences.

If the patient reports falls or balance impairment related with an specific domain, exercises related with this domain can be prescribed. Or exercises targeting multiple domains can be prescribed if no other clinical signs justify focusing on one single domain.

  1. Other factors overrule focusing on the most compromised domain:

It can be more immediate prescribing exercises which target other domains, if other clinical findings overrule focusing on the most impaired domain.

E.g. the balance profile of a patient might show that the most compromised domain is “sensory orientation”, but the patient reports several falls related with tripping over obstacles. Additionally, the clinical examination shows unilateral weak dorsiflexion of a foot. Then exercises targeting “reactive stepping” could be prescribed even if this domain is not the most compromised according to the balance profile. We recommend though, always to consider the relationship between the result of the balance profile and the additional clinical findings. Less apparent interactions can sometimes become clear only when looking deeper into the mechanisms of the patients´ balance impairment and falls. For instance, a detailed anamnesis might reveal that, what this patient perceives as obstacles which makes her trip is often uneven surfaces like cobblestone pavement, and the falls is more likely explained by losing balance because of her inability to maintain balance on the uneven surface. In this context the relationship between the balance profile and the patients´ personal experiences is more obvious and the domain “sensory orientation” might be chosen as the primary focus anyway.

Prescribing exercises according to a less impaired domain can be relevant for instance if the patient is too affected by fear of falling to practice exercises related with the most compromised domain or the assessor judge that the patient will benefit from experiencing some degree of self-efficacy by practicing “easy” exercises when initiating the rehabilitation process. Exercises related with more impaired domains can then be prescribed later during the rehabilitation period.

In conclusion, the balance profile is a crucial guide for prescribing exercises, but comprehensive clinical judgement should always be the basis of any clinical decisions. Any target domains can be chosen if regarded appropriate, but it is recommendable though, eventually to target the patients' most compromised domain(s) at some time during rehabilitation. Otherwise it is likely that “the weakest link in the chain” will not be fixed.

Please refer to figure 2 for an overview of the clinical decision algorithm applying the balance profile in relation to additional factors.

Currently, we offer two methods for producing the STABLE balance profiles. The profiles can be produced "manually" by plotting the patients´ scores relative to the normative values. Additionally, the balance profiles can be produced on this website applying the online calculator.

 decision tool STABLE 11