From the Lab

Stroke-specific outcome measures for the lower extremities (LEs) are, relative to upper extremity (UE) tests, simple. There are several reasons for this. LE tests produce physically large results. These results tend to be easy to see.

Consider the difference between the distal portions of the upper vs. lower extremity. The lower-extremity analogue of the hand is not visible, and not tested.

This goes to the core of the "gotcha" question often asked by clinical instructors of their students: "What comes back first after stroke: the arm or the leg?"

A politically wise student will answer, "the lower extremity." That is typically what instructors want to hear. However, the premise of the question is questionable. A more thoughtful question is, "What comes back first, finger extension or toe extension?" The analogue to the fingers, typically thought of as the last and least predictable part of the body to recover after stroke, are the toes. But nobody ever looks at the toes.

Other reasons that the lower extremities are easier to test are illuminated by the motor and sensory homunculi, the point-to-point representation of muscles on the brain. The representation of the hand is very large. The representation of the foot is very small.

The intricacies of the hand, and all that the hand can accomplish, requires intricate testing. Further, from a purely anatomical standpoint, not only does the hand do more things than the foot, the shoulder moves through many more planes than its analogue, the hip.

Top Predictor

Walking speed is core to LE testing. Walking speed is reliable, valid and very sensitive. Walking speed is predictive of everything from future health status and discharge location (i.e., home, skilled nursing) to falls and fear of falling.¹

The sensitivity of gait speed bodes well for therapists in their attempt to convince payers that further LE therapy is needed. For instance, while speed of gait may be increasing incrementally and subtly, that same progress would not be captured across either the assistance needed (min/mod/max) or distance walked continuum. In other words, the more subtle the outcome measure, the easier it is to justify further treatment. Vis-à-vis gait speed, there is no analogue in the UE-although UE tests do include speed as part of the outcome measure.

The nature of "function" in the UE requires testing across a never-ending set of abilities. There are two primary categories of testing in the LEs-transfers and ambulation. In the UEs there are dozens just for grasp. There is cylindrical grip, tip grip (one for each finger against the thumb), hook grip, palmar grasp, spherical grip, lateral grip and on and on and on. And all of these grasp types are multiplied by varying what is grasped; standardized tests in the UE are completed within the context of activities as diverse as using the phone, buttoning, using a fork and knife, and flipping cards.

Because of all the possibilities and potential of the UE, its testing tends to be based on highly nuanced qualifiers.² Examples of the qualifiers include words such as "some," "attempts to," "influenced to some degree by synergy," "slightly slower," "lacks precision," etc.

And there is another problem with some of these UE tests. Consider this group: the Box and Block (B&B), Arm Motor Ability Test (AMAT), the upper-extremity portion of the Fugl-Meyer (AMFM) and the Action Research Armtest (ARA). All of the tests require special equipment.

The equipment needed falls into these four categories: 1) very easy to find items (AMFM); 2) easy to find but a lot of items (AMAT); 3) items that must be purchased in a specialty rehab catalog or store (B&B); and 4) items that must be manufactured because they are not available for purchase (ARA).

Getting Real

Despite their complications, there are several good reasons to embrace the nuanced snapshot these tests provide. First and foremost is the fact the UE is tagged as either "non-functional" or "functional." But much of recovery is a leap of faith that happens between the two.

So a test that provides insight to the incremental sub-steps between non-functional and functional will provide a realistic view of recovery.

Further, this nuanced perspective on progress of recovery can provide justification, just as the sensitive measure of gait speed does, for further therapy. UE tests are nuanced because they have to be; nuanced measures provide nuanced results. UE tests are worthwhile despite their pain.

Stroke survivors deserve a nuanced perspective on their recovery. Therapists deserve a more three-dimensional view of recovery than the min/mod/max/functional/non-functional perspective. And both therapists and stroke survivors deserve tools that provide the justification, if warranted, for further treatment. 

References

1. Fritz, S., & Lusardi, M. (2009). White paper: Walking speed: The sixth vital sign. Journal of Geriatric Physical Therapy, 32(2), 2-5.

2. Levine, P. (2009). Upper-extremity, stroke-specific testing: Are lab-tested, stroke-specific outcome measures ready for clinical prime time? Physical Disabilities Special Interest Section Quarterly, 32(3), 1-4.

Peter G. Levine is co-director of the Neuromotor Recovery and Rehabilitation Laboratory (rehablab.org) and the author of Stronger After Stroke (Demos Health, 2008). He also conducts seminars teaching research-based, neuroplasticity-producing stroke recovery strategies. E-mail him at strongerafterstroke@yahoo.com.