Amputee Mobility Predictors Bethany Hightower, Lexi Okurily

Functional Ambulation Achieved Hip disarticulation <10% AKA (unilateral) 10-37% Knee disarticulation 36-76% BKA (unilateral) 70-100% Less than 10% of people with a hip disarticulation can ambulate

What is it? Assessment tool utilized to determine a lower limb amputee’s functional mobility status with or without a prosthesis Helps determine amputee’s K Level for Medicare Also helps estimate an amputee’s six minute walk test distance Can be utilized for partial foot, transtibial, knee disarticulation, transfemoral, hip disarticulation

What is it? Designed to measure hip extensor and abductor strength which both predict successful prosthetic ambulation Helps maintain pelvic control during ambulation Influences symmetrical step length Age plays a role Takes about 15 minutes to administer; Test is completed in a hard chair with arms

AMPPRO Vs. AMPnoPRO Scoring 0= Unable to perform task 1= Required minimal assistance or task was minimally performed 2= Independence of task AMPPRO Total score with prosthesis is out of 47 K Level… K1= 15-26, K2= 27-36, K3= 37-42, K4= 43-47 AMPnoPRO Total score without prosthesis is out of 43 K0= 0-8, K1= 9-20, K2= 21-28, K3= 29-36, K4= 37-43

It is a 20-item assessment tool designed to evaluate the skills required for successful prosthetic ambulation. Items 1 and 2 assess sitting balance; 3 through 7 assess simple mobility: transfers and coming from sit-to-stand; 8 through 13 assess standing balance activities: single-limb stance and pick up object from floor; and 14 through 20 assess components of gait: step length, transverse obstacle, and ascend and descend stairs. All subjects performed the AMP wearing their prostheses.

Components of AMP Sitting balance Sitting reach Chair to chair transfer Sit to stand Attempts to sit to stand Immediate standing balance Standing balance Single limb standing balance Standing reach Nudge test Sitting balance- arms across chest; Sit reach- 12in beyond extended arms midline to sternum; Chair to chair- chairs at 90 degrees, patient can use UE; Sit to stand= arms across chest; Attempts to sit to stand= unable without assistance, 1 or more than 1 attempt; Single limb- time up to 30 seconds, both limbs (grade quality, not quantity); Standing reach- same as sitting; Nudge test- feet as close together as possible, examiner pushes lightly on pts sternum with palm of hand 3x (toes should rise)

Components of AMP Continued 11. Eyes closed 12. Pick up objects off the floor 13. Sitting down 14. Initiation of gait 15. Step length and height 16. Step continuity 17. Turning 18. Variable cadence 19. Stepping over an obstacle 20. Stairs 21. AD selection AD Selection 0= Bed bound 1= Wheelchair/Parallel bars 2= Walker 3= Crutches (axillary or forearm) 4= Cane (straight or quad) 5= None

K Classifications K0= Ability to sit and stand without difficulty K1= Able to sit to stand, moderate standing balance, initiates gait, uses an AD, low endurance K2= Standing balance, maintain balance with assistance when nudged, able to take full stride with one foot, can complete 3 step turn without intervention K3= Single limb balance, balance without assistance when nudged, “normal” gait (good stride length & continuity), turns independently with less than 3 steps, able to climb stairs and step over obstacles K4= Single limb balance with both legs, able to perform most tasks with good balance, gait is symmetrical (able to vary cadence, navigate obstacles, and stairs independently) AMPnoPRO K0= 0-8 AMPnoPRO(out of 43) and AMPPRO (out of 47)= K1-K4

Evidence Measurement study with 191 lower limb amputees (18-100 y/o) Gailey (2002) showed the validity and reliability of the tool (AMPPro & AMPnoPRO) Interrater reliability was.99 for subjects tested with and without their prosthesis; intrarater reliability was.96 and.97. AMP has a strong correlation with the 6MWT and amputee activity survey AMP has a negative correlation with age and comorbidities 191 LE limb amputees aging 18-100 That decision is based on a subjective evaluation of the patient's past history (including prior prosthetic use, if applicable); the patient's current condition, including the status of the residual limb; concommitant medical problems; and the patient's desire to ambulate. To standardize this process would require an instrument that could classify the amputee subject by functional level and quantify function. The instrument would need to be applicable across a wide range of functional abilities. The Amputee Mobility Predictor© (AMP), was designed to meet the following criteria: (1) to be administered before prosthetic fitting; (2) to be clinically feasible in terms of time, resources, and ease of use, and; (3) to assist in assigning an MFCL for prosthetic prescription of Medicare-eligible patients.

A model for evaluating mobility among seniors with lower-limb amputations of vascular origin Observational and transversal study with 10 participants Proposition of a new model to evaluate the mobility of older amputee population Potential mobility indicators do not accurately predict effective mobility In the population assessed, these factors reduced effective mobility: living alone no rehabilitation Pain limited social support poor muscle strength This model integrates the concepts of potential mobility (e.g. balance, speed of movement), effective mobility (e.g. life habits, movements in living areas) and factors that modulate these two types of mobility (e.g. strength, sensitivity, social support, depression). The model generated 4 different profiles (categories) of participants ranging from reduced to excellent potential mobility and low to excellent effective mobility, and characterized the modulating factors. participants who perform well on traditional measures done in the laboratory or clinic are not always those who perform well in the real world Population ranging 51-83 y/o, assessing 8-18 months post discharge of acute care. Only 10 participants

What about Bilateral Lower Limb Amputees? Cross-sectional study with 26 males Does not effectively assess the mobility of BLLAs Current AMP has unintentional bias for those with bilateral limb loss Presence of at least one knee is necessary to achieve a maximum score Required modifications to appropriately determine participation restrictions and abilities. Without modifications, even the highest functioning BLLAs could not obtain a maximal score Cross sectional study of 26 males- BLLAs (BTTA most common, then BTFA or combo ) example, for a person with two prosthetic knees, the ability to rise out of chair without the use of the upper limbs is regarded as impossible

Clinical Ramifications Helps determine a lower limb amputee’s functional mobility status with or without a prosthesis Aides in the justification of improving K Levels Justification for different prosthetic Medicare reimbursements

References Amputee Mobility Predictor Questionnare Accessed at http://www.oandp.com/opie/ampdownloads/assets/pdfs/amppro.pdf Gailey RS, Roach KE, Applegate EB, Cho B, Cunniffe B, Licht S, Maguire M, Nash MS. The amputee mobility predictor: an instrument to assess determinants of the lower-limb amputee's ability to ambulate. Archives of physical medicine and rehabilitation. 2002 May 31;83(5):613-27. http://www.austpar.com/portals/gait/tools.php Raya MA, Gailey RS, Gaunaurd IA, Ganyard H, Knapp-Wood J, McDonough K, Palmisano T. Amputee Mobility Predictor-Bilateral: A performance-based measure of mobility for people with bilateral lower- limb loss. J Rehabil Res Dev. 2013 Jul 1;50(7):961-8. Vincent C, Demers É, Moffet H, Corriveau H, Nadeau S, Mercier C. Use of an innovative model to evaluate mobility in seniors with lower-limb amputations of vascular origin: a pilot study. BMC geriatrics. 2010 Sep 20;10(1):1.