Make Sure You Measure Up - Mobile Physical …

1 make Sure You Measure Up Part III of IV. by Kenneth L. Miller, PT, DPT. This article is the third in a series of four devoted to stan- gait speed can be easily misinterpreted or confusing. Gait dardized tests that may be performed in the home setting speed has been reported in multiple units of time and mul- for community dwelling older adults. Parts III and IV of tiple units for distance in both the English and metric sys- this series will describe two testing measures: gait speed tems : ft/sec, m/sec, cm/sec, ft/min, m/min and mph to and single limb stance, respectively, which are included in name a ,4,5,6,7. the Motor Function Domain of the National Institutes of In a more recent study using a larger sample size to Health (NIH) Gait speed (GS) is commonly determine normal (comfortable) gait speed Bohannon known as walking speed , gait velocity and walking veloc- compared gait speed measured over 8 and 20 The ity.

2 GS is included in the NIH toolbox because of its objec- Summary of Gait speed over 8 and 20 feet stratified by tivity, validity, reliability, freely available for use and ease gender and age is found on Table 3. Mean gait speeds were of administration. Gait speed is highly recommended as the ft/sec and ft/sec over 8 and 20 feet sixth vital sign because of its ability to predict future Speeds measured over both the 8 and 20 foot distances health status, its ease of administration, ease of grading and were correlated strongly (r=.933, p<.001).6 Bohannon con- interpretation and minimal cost cluded that measurement of gait speed was feasible in the In order to use gait speed as an objective test, adminis- home care setting for distances of less than 20 feet as long tration of the test needs to be con- as one step is possible before mea- sistent.

3 Researchers have reported surement is ,9 Finding dis- Table 1. Mean of comfortable gait speed and using differing distances such as tances of 8 feet of unobstructed maximum gait speed presented by gender 20 ft, 10 m or 20 m for determina- floor space with one step distance and decade of tion of gait ,2,3 Gait speed before and after the test distance is Gender/ Comfortable gait Maximum has been divided into two different much more readily available in the decade speed (cm/sec) gait speed gait speed measures; one called home setting over the longer dis- (cm/sec). comfortable (or preferred) gait tances used to Measure gait speed . Men speed (cgs) and the other called The strong correlation that exists 20s fast (or maximum) gait speed for cgs measures from 8 and 20. 30s (fgs). Comfortable gait speed is feet gives the home care clinician 40s defined as a person's usual or confidence to use the cgs for com- 50s comfortable, self-selected pace and parison to normative data and for fast gait speed as a person's as 60s its predictive value.

4 Fast as safely possible , self-se- 70s In the protocols described by lected ,4 Normative data has Women Bohannon, Lusardi et al, and been provided for both cgs and fgs 20s Steffen et al, there is an accelera- by Bohannon and Lusardi et ,5 30s tion phase and deceleration phase See Table 1 and 2 for normative 40s as part of the gait speed Measure - data for gait speed . The data is 50s ment ,4,5 See Table 4 for gait stratified by gender and age. 60s speed measurement procedure. Lusardi et al accounted for use of 70s Bohannon measured the time for a assistive devices in their data col- subject to walk a distance of lection and as expected, those sub- m (25 feet) allowing for several jects who used an assistive device had slower cgs than sub- meters to accelerate and decelerate before and after the test jects who did Steffen et al reported strong test-retest Lusardi et al measured the gait speed using a dis- reliability for both cgs (ICC=.)

5 97) and fgs (ICC=.96).3 The tance of m (12 feet) allowing for 3 m before and 3 m researchers noted trends for decreased cgs and fgs with in- after the test distance allowing for acceleration and decel- creasing ,4,5 Use caution when comparing normative eration, Steffen et al had the subjects walk 10. data from different authors because the units of Measure for m and the test distance was the middle 6 m allowing for 2. 12 Home Health Section - APTA Fall 2009. m acceleration and 2 m The protocol as out- cross busy city Knowing required gait speed to lined in the NIH toolbox instructs the participant to walk as cross a street safely, can assist a therapist in establishing a quickly as possible at a pace he or she can maintain for the patient's homebound status and/or functional status. 20 foot walk distance as Can gait speed be the time is used to predict a risk for Gait speed is a Table 2.

6 Mean of comfortable gait speed and maximum gait speed falling? Yes, Harada et powerful tool that can presented by gender, age and use of assistive al found gait speed to have predictive value. demonstrate good sensi- Cesari et al reported that Age (yr) Group Mean for Mean for tivity and specificity gait speed of less than 1 Comfortable gait Maximum gait (80% and 89% respec- m/sec identifies persons speed (m/sec) speed (m/sec) tively). The cut off at high risk of health- 60-69 Male value was 34 m/min at related outcomes includ- Female increased risk for fall- ing mortality and physi- Overall Being able to pre- cal disability in well- 70-79 Male dict falls risk, determine functioning older Female health risk and mortal- Montero- Overall ity, predict discharge Odasso et al found that 80-89 Male disposition and length gait speed is also predic- Female of stay, define commu- tive of adverse health- No Device nity ambulation and related outcomes in Device home bound status us- well-functioning elderly Overall ing objective quantifi- persons and recommend 90-101 Male able data makes gait it be considered as a Female speed a very powerful vital sign.

7 11 Hardy et No Device tool for the therapist al reported that im- Device treating patients in the provements in gait Overall home or in any setting. speed predict a substan- How do you know if tial reduction in mortal- gait speed improve- Studenski et al reported that gait speed of less than .6 ments are truly a meaningful change? It has been reported m/sec is predictive for future risk of hospitalization and by Perera et al that the best initial estimates of small mean- decline in health and Rabadi and Blau reported ingful change are near m/sec for gait speed and sub- that a gait speed of .15 m/sec or less is predictive of length stantial meaningful change is closer to 14. of stay and discharge disposition to a sub acute facility. Palombaro et al reported a standard error of the Measure Not only can gait speed be used as a predictive mea- and minimal detectable change for habitual (cgs) and fast sure of health and mortality, it can be used as a Measure to (fgs) to be m/sec and m/sec respectively after hip establish safety when ambulating outdoors.

8 Robinett and Vondran studied distance requirements and gait velocity in Gait speed is a quick, inexpensive test that is valid, order for a person to be considered a community ambulator. reliable and easily administered in the home care setting. Necessary velocity varies from m/min ( m/sec) in Necessary equipment is minimal and the power of this tool a rural setting to m/min ( m/sec) in an urban set- is great. This Measure should be considered for vital sign ting in order to cross a walkway Shumway-Cook et status as it can predict mortality, hospitalization, discharge al report necessary gait speeds of 70 m/min to 73 m/min to disposition and for adverse health outcomes in well-func- tioning older adults. The norma- Table 3. Summary of Gait speed (ft/sec) over 8 and 20 feet stratified by gender and tive data available is useful as a age.

9 6 guide for comparison with pa- Gender Age Range (years) Gait speed over 8 Feet Gait speed over 20 Feet tient values. These scores can be Means SD (95%CI) Means SD (95%CI) used to document meaningful Female 50-59 progress that is quantifiable and 60-69 reproducible. Gait speed data is 70-79 available as a reference to deter- 80+ mine if a patient is a safe com- Male 50-59 munity ,15 Would the 60-69 patient make it across the street safely before the light changes 70-79 green? Is the patient at risk for 80+ adverse health outcomes and Home Health Section - APTA Fall 2009 13. falling? These questions can be answered with a gait speed 7. Robinett CS, Vondran MA. Functional Ambulation Ve- measurement which only takes minutes to complete. Con- locity and Distance Requirements in Rural and Urban sider adding this tool to your assessment toolbox.

10 The NIH Communities. Phys Ther 1988;68(9):1371-1373. did. 8. Bohannon RW. Measurement of Gait speed of Older Adults is Feasible and Informative in a Home-care Setting. References J Geriatr Phys Ther 2009;32(1):22-23. 1. NIH Toolbox. Assessment of Neurological and Behav- 9. Breniere Y, Do MC. When and how does steady state ioral Function. gait movement induced from upright posture begin? J. WebPart%20 Accessed September 12, Biomech 1986;19:1035-1040. 2009. 10. Cesari M, Kritchevsky SB, Penninx BWHJ, Nicklas BJ, 2. Fritz S, Lusardi M. White Paper: Walking speed : the Simonsick EM, Newman AB, Tylavsky FA, Brach JS, Sixth Vital Sign. J Geriatr Phys Ther 2009;32(2):2-5. Satterfield S, Bauer DC, Visser M, Rubin SM, Harris TB, 3. Steffen TM, Hacker TA, Mollinger L. Age- and Gender- Pahor M. Prognostic Value of Usual Gait speed in Well- Table 4.