Objectives: Intended Audience. Upon completing this educational module the participant will:

Transcription

1 An evidence-based guide to Quantifying Fall Risk in Persons with Lower Extremity Amputation(s) M. Jason Highsmith, PT, DPT, CP, FAAOP Stephanie Hart-Hughes, Hughes, PT, MSMS, NCS Gail Latlief, DO, FAAPMR James D. Switzer, PT Donna J. Blake, MD Gail Powell-Cope, PhD, ARNP, FAAN Funded by Veterans Health Administration National Center for Patent Safety Objectives: Upon completing this educational module the participant will: Describe the prevalence and significance of falls in lower extremity (LE) amputees Identify situations and circumstances most likely to cause or result in falls Describe functional performance measures to identify fall risk in this population Identify interventions to minimize falls and fall related injury in this population Intended Audience The intended audience for this educational module includes clinicians and researchers involved in the rehabilitation of persons with lower extremity amputation(s). Authors believe the information will have particular relevance for members of specialized fall clinics or researchers conducting clinical trials that utilize falls as an outcome measure.

2 Background & Significance Module Flow Chart Functional Performance Measures related to Fall Risk Assessment Intervention Neurocom Five Time Sit to Stand Test Four Square Step Test Timed Up and Go Test 8 Up & Go L Test of Function 180 Degrees Turn Test Single Limb Balance Test Functional Reach Test Multi-Directional Reach Test Gait Speed, Velocity Recall of Stumbles & Falls Prosthesis Evaluation Questionnaire-Addendum (PEQ-A) Background & Significance There are 1.8 Million persons in the U.S. living with loss of a limb 1,2 This is 1 in 190 Americans This number is expected to double by the year The annual cost of providing care for this group of individuals on an acute and subacute basis is >$4 Billion annually. The majority of this group is: Male Elderly have loss of the lower extremity due to vascular disease many are veterans. Background & Significance Lower extremity amputation, regardless of etiology, is known to compromise: 3-5 Gait Balance Stability Reaction to slip/fall events When a limb is lost to vascular disease, numerous comorbidities and risk factors are in place further increasing the likelihood of falls f in this unique population. Common comorbidities include: Advanced age Neuropathy of the sound side/intact limb (assuming unilateral) High probability of partial foot ulceration and/or amputation of the sound side/intact limb Presbyopia and/or retinopathy

3 Background & Significance Falling is pervasive in persons with LE amputation % of LE amputees will likely fall while in the inpatient rehabilitation setting 18% of these, will experience an injury associated with the fall 1/3 of LE amputees will have complications associated with a fall while undergoing inpatient rehabilitation The majority of falls occurred during wheelchair use : Self-transfers Reaching Authors indicated that poor balance played a role Background & Significance Risk factors associated with increased risk of falling while admitted for inpatient rehabilitation : 3,5,9 Age of > 71yrs Length of stay b/t days 4 or more comorbidities Cognitive impairment 2 or more as needed medications Use of benzodiazepines or opiates Risk factors associated with fall related injury Bilateral amputation Fall during the day shift Additional considerations: Extrinsic factors (e.g. spills, obstructions, pets) Intrinsic factors (poor vision, poor muscular strength, poor motor or control, poor reaction strategy Background & Significance amputees ambulating at an unlimited community level continue to suffer several falls per month. 6,10,11 MFCL Functional Description Prosthetic Feet Prosthetic Knees K0 Non-ambulatory. Not a candidate for a prosthesis. None None K1 Limited and unlimited household ambulation. Level surfaces. Fixed cadence. Transfers and therapeutic use. Basic Feet: External Keel, SACH, Single Axis Basic knees K2 Limited community ambulation. Able to traverse low-level environmental barriers (curbs, ramps, stairs, uneven surfaces). Multi-axial feet, Flexible Keel feet, Axial rotation (ankle) unit K3 Community ambulation. Variable cadence gait (or potential). Most environmental barriers. Dynamic response feet Fluid & Pneumatic knees K4 Children. Persons with bilateral involvement. Active adult. Athletes. Exceeds basic use. Any Any

4 Background & Significance Several physical rehabilitation strategies, assessment tools and interventions are described in the literature to identify and ameliorate the incidence i and complications associated with falling and mortality in this group. 9,12,13 They range from: very global strategies to maximize functional recovery and optimize ize coordination of care i.e. post-operative operative discharge destination: persons admitted to inpatient rehabilitation immediately following acute care have a significantly higher survivability one year post-amputation than those individuals discharged to either skilled nursing facilities or home. Unfortunately, it is reported that inpatient rehabilitation is insufficiently utilized following amputation secondary to vascular disease. to very specific, individualized interventions i.e. use a stump protector while in inpatient rehabilitation. i.e. use of a chair alarm wheelchair skills training or patient education to prevent falls from wheelchair during self transfer. Functional Performance Measures related to Fall Risk Assessment Please Note: 1. This is not an exhaustive list. 2. The majority of these assessments have not been validated in the amputee population. However, they are widely used in practice despite their t lack of a robust evidentiary basis. Please Note: Use of these assessments and interventions should be conducted by a trained and appropriately credentialed professional. Important considerations include sound clinical judgment, proper safety equipment and an appropriate skill level of the patient. For instance, comorbidities that degrade stability and increase fall risk should all be considered in advance of selecting an appropriate fall risk assessment and/or intervention.

5 Functional Performance Measures related to Fall Risk Assessment The following tools will be reviewed: Neurocom Five Time Sit to Stand Test Chair Stand Test Four Square Step Test Timed Up and Go Test 8 Up & Go L Test of Function 180 Degrees Turn Test Single Limb Balance Test Functional Reach Test Multi-Directional Reach Test Gait Speed, Velocity Prosthesis Evaluation Questionnaire-Addendum (PEQ-A) Recall of Stumbles & Falls Neurocom Non- Evaluate the contribution of sensory inputs and motor control in balance n/a n/a Selected References Kaufman KR et al. Gait Posture Expensive equipment. Time consuming to administer evaluation. Specialized training required. Considered the Gold Standard for Balance Assessment. In non-amputees, able to differentiate between sensory and motor impairments contributing to balance deficits. Neurocom Procedure: Patient stands on a moveable dual force platform while harnessed for safety. Depending on the selected test, the visual surround and/or forceplate(s) ) move. Forceplate accurately measures movement of the Center of Gravity.

6 Non- 5 times sit to stand test To measure the amount of time required to rise from a chair 5 times. Evaluates lower extremity strength, power, endurance and center of gravity control. For non-amputees, normative values are available for the following age ranges: 11.4 sec. (60 to 69 years) 12.6 sec. (70 to 79 years) 14.8 sec. (80 to 89 years) Increased risk for falls in community dwelling elderly if unable to rise from a chair without arm use. N/A Selected References Bohannon RW. Percept Mot Skills Potential for compensatory strategies (ie. Un-weight prosthetic limb during task) Some patients are unable to stand five times Negligible time Negligible equipment Minimal space requirement 5 times sit to stand test Procedure: Patient sits on a standard height chair with their arms crossed over their chest. Therapist times how long it takes for the patient to perform the task of sit to stand task five times. Time begins when therapist vocalizes the go instruction and stops when patient returns to a sitting position following his fifth repetition. Non- Chair Stand Test To measure the number of repetitions of the sit to stand task a patient can perform in 30 seconds. Evaluates lower extremity strength, power, endurance and center of gravity control. N/A for fall risk. Increased risk for falls in community dwelling elderly if unable to rise from a chair without arm use. N/A Selected References Jones CJ et al. Res Q Exerc Sport Hart-Hughes S. Balance Assessment Handbook Potential for compensatory strategies (i.e. un-weight prosthetic limb during task) Preferable for patients who are only able to perform minimal repetitions. Minimal space requirement, minimal equipment and minimal time.

7 Chair Stand Test Procedure: Patient sits on a standard height chair with their arms crossed over their chest. Participant is instructed to rise to a full stand and return back to a fully seated position after the signal go is given The score is the total number of stands executed correctly within 30 seconds. If the patient is more than half way up at the end of 30 seconds it is counted as a full stand. Four square step test Non- To assess the patient s ability to step over low lying objects, rapidly transfer weight from one leg to another and change directions in a coordinated manner. > 12 seconds indicates an increased risk for falls in community dwelling older adults. > 24 seconds identifies multiple fallers in unilateral transtibial amputees Selected References Dite W. Arch Phys Med Rehabil Dite W et al. Arch Phys Med Rehabil Not validated beyond unilateral transtibial amputee involvement. Patient can use preferred walking aid. Incorporates more complex, high level stepping movements and direction changes. Minimal space requirement, equipment and time. Four square step test Procedure: Square formed with 4 canes on floor Patient instructed to step forward, right, backward and left then return to starting square. Timing starts at first foot contact with floor in square 2 and ends with last foot contact in square 1 Patient can use preferred walking aid Start time End time

8 10ft Timed Up and Go (TUG) Test Non- To test functional mobility. Specifically, TUG measures a patient s ability to stand up, walk 10 ft, perform a 180 degree turn and return to the start position. >13.5 seconds identifies increased risk for falls in community dwelling older adults. > 30 sec indicate probable difficulties performing ADLs. >19 sec identifies multiple fallers in unilateral transtibial amputees Selected References Dite W et al. Arch Phys Med Rehabil Shumway-Cook A, et al. Phys Ther Not validated beyond unilateral transtibial amputee involvement. Task may be too simple for higher level patients. Allows for analysis of a combination of functional tasks (transfers, turning, ambulation). Minimal space requirement, equipment and time. Patient can use preferred walking aid. Timed up and go (TUG) test Procedures: Patient is asked to stand up, walk to a line placed on the floor 10 feet away, turn around and return to the original seated starting position. Patient is requested to perform task at comfortable walking speed. Time begins when the go signal is verbally given. Time is stopped once the patient has returned to a seated position. on. Use of preferred walking aid is permitted. Non- 8 ft Up and Go Test To test functional mobility. Specifically to measure patient s ability to stand up, walk around a cone located 8 feet away and return to the start position. > 8.5 seconds identifies increased risk for falls in community dwelling older adults. N/A Selected References Rose DJ, et al. J Aging Phys Activity Not validated in the amputee population. Task may be too simple for higher level patients. Allows for analysis of a combination of functional tasks (transfers, turning, ambulation). Minimal space requirement, equipment and time. Patient can use preferred walking aid. Cone provides a strong visual turning cue for patients. Requires less space to perform compared to the Timed Up and Go (TUG) Test.

9 8ft 8 ft Up and Go Test Procedures: Patient is asked to stand up, walk around a cone placed on the floor f 8 feet away and return to the original seated starting position. Patient is requested to perform task as quickly as possible. Time begins when the go signal is verbally given by the therapist. Time is stopped once the patient has returned to a seated position. on. Use of habitual walking device is permitted. L Test of Functional Mobility Modification of the TUG for persons with LE amputation Non- To test functional mobility. Specifically measures an amputee s ability to perform two transfers and four turns over a total distance of 20 meters. N/A Transtibial s: 29.5 (+ 12.8) sec Transfemoral s: 41.7 (+ 16.8) sec Selected References Dite W et al. Arch Phys Med Rehabil Deathe AB. Phys Ther Requires more space than TUG More complex than the TUG test: requires different types of turns (90 and 180 degree turns) in different directions. Patient can use preferred walking aid. Cone provides a strong visual turning cue for patients. Minimal equipment and time requirements. L Test of Functional Mobility Modification of the TUG for persons with LE amputation Procedures: Patient is asked to stand up, walk 3 meters, turn left around a cone placed on the floor, walk 7 meters, turn around cone and return along the same path finishing in the original seated starting position. Patient is requested to perform task at comfortable walking speed. Time begins when the go signal is verbally given by the therapist. Time is stopped once the patient has returned to a seated position. Use of habitual walking device is permitted. 7m 3m

10 180 degrees turn test To objectively quantify, by step count or time, the common, yet often problematic mobility task of turning around Non- Turn steps > 5 steps Unilateral Transtibial s: Turn time of > 3.7 seconds Turn steps > 6 steps Selected References Dite W et al. Arch Phys Med Rehabil Nevitt MC et al. JAMA Not validated beyond unilateral transtibial amputee involvement. Methods vary in literature. Recommend measuring performance in both directions. Only evaluates a single task. Challenging to guard patient without influencing outcome. Consider a harness. Specifically evaluates ability to turn around. Patient can use preferred walking aid. Minimal space requirement, equipment and time. 180 degrees turn test Procedures: Patient is positioned in standing in an uncluttered space. Patient instructed to turn 180 degrees towards the sound limb. Test repeated turning towards the involved limb. Record turning time and/or number of steps Single Limb Stance Test Non- To quantify the amount of time an individual can stand on 1 foot Single Limb stance time of < 30seconds is associated with an elevated fall risk in older, community dwelling adults. N/A Selected References Hurvitz EA, et al. Arch Phys Med Rehabil Performance may be dependent upon componentry in patients with amputation. Higher level balance test Minimal space requirement, equipment and time

11 Single Limb Stance test Procedures: Patient is asked to cross arms over chest (or clasp hands) and lift one foot off the floor. Timing is initiated when foot is lifted off the floor and stops when any portion of the foot touches the floor. Testing is performed on each leg and recorded separately. Safety: Parallel bars Gait Belt Test sound & amputated sides Non- Functional Reach Test To examine a commonly performed functional task. Specifically, to objectively measure an individual s maximal ability to voluntarily reach forward without moving their feet. Reach <10 inches: 2x more likely to become a recurrent faller* Reach <6 inches: 4x more likely to become a recurrent faller* N/A Selected References Duncan PW et al. J Gerontol A Biol Sci Med Sci Permits compensation via abnormal trunk motions. -Test score not standardized for patient height -Voluntary reaching performance may be confounded by other variables including fear of falling and back pain. -Minimal space requirement and time. -Measures a commonly performed functional task * Recurrent faller is classified as 2 or more falls in a 6 month h period. Functional Reach Test Procedure: Place a yardstick on the wall at the level of the patient s acromion process. Position yard stick level to the floor. Instruct the patient to reach as far as possible in the forward direction without losing balance or moving feet. Score recorded is the difference between ending and starting distance reached as measured by the position of the index finger. Two trials are permitted. Patient s s feet must remain flat on the floor at all times. Trunk rotation on and other extraneous movements are permitted but should be noted. Consider shoulder range and recording accuracy Consider compensatory spinal rotation

12 Multi-Directional Reach Test Non- To objectively measure an individual s maximal ability to voluntarily reach forward, backwards, to the left and to the right without moving their feet. N/A N/A Selected References Newton RA. J Gerontol A Biol Sci Med Sci Test scores not standardized by patient height -Voluntarily reaching performance may be confounded by other variables including fear of falling and back pain. -Permits compensation via abnormal trunk motions. -Test is a portable, valid measure of limits of stability - Minimal space requirement and time Multi-Directional Reach Test Procedure: Place a yardstick on an IV pole, tripod or back of a rolling mirror ror at the level of the patient s acromion process. Position yard stick level to the floor. Instruct the patient to reach as far as possible in the forward direction without losing balance or moving feet. Score recorded is the difference between ending and starting distance reached as measured by the position of the index finger. Repeat procedure in backwards and sideways directions. - Two trials are permitted in each direction. - Patient s s feet must remain flat on the floor at all times. Trunk rotation on and other extraneous movements are permitted but should be noted and accounted for in interpretation of the results. Non- Selected References Gait Speed, Velocity To objectively measure the speed a patient walks over a given distance. Measure is often used to describe mobility status or monitor functional change over time. <0.56 m/s for risk of recurrent falls. 28 No known reference values to identify fall risk. Habitual Walking Speeds for amputees range from: 0.75m/s to 1.22m/s VanSwearingen JM et al. J Gerontol A Biol Sci Med Sci Potentially space depending on distance used (Many different distances found in the literature e.g. 8ft, 15ft, 50ft, 75m) -Commonly used outcome measure -Minimal equipment and time -Patient can use preferred walking aid

13 Gait Speed, Velocity Known Distance Procedures: Time is recorded as a patient walks a known distance. Many different distances have been used in the literature (e.g. 8ft, 15ft, 50ft, 75m) Gait speed determined via simple calculations Pt allowed to use habitual walking device. Test generally performed at habitual/self-selected selected walking speed however may also perform test at maximal speed to assess ability to adjust speed (functional significance) Accommodate for patient acceleration and deceleration by demarcating 3 ft on either side of the distance to be timed. Distance/Time: Clinical measures (commonly) = feet/second Literature (commonly) = m (or cm)/second So, convert: 1 foot = 30.48cm or.3048m Example: 15feet / 5sec 15 feet x.3048m = 4.57m 4.57m / 5sec =.914m/s Prosthesis Evaluation Questionnaire-A (PEQ-A) Non- To establish thru patient recall via a survey instrument, the estimated number of stumbles, semi-controlled and uncontrolled fall events experienced within a given time frame. N/A- Instrument. Stumble(Range)- Frequency: Number: Semi-controlled Falls (Range)- Frequency: Number: Uncontrolled Falls (Range)- Frequency: Number: Selected References Hafner BJ et al. Arch Phys Med Rehabil Not all items are related to stumbles and falls Requires literacy Brief, written instrument Reference values available in the literature Prosthesis Evaluation Questionnaire-A (PEQ-A) Procedure Patients complete the 14 items below. Items B, C and D are visual analogue items Items B1, C1 and D1 are open ended items.

14 Recall of Stumbles and Falls To establish thru patient recall the estimated number of stumbles and/or falls experienced within a given time frame. Descriptive studies report that over 33% of individuals over the age of 65 fall at least once in a 12 month period. This number increases with age and co-morbidities. 29,30 Descriptive studies report that 52% of lower extremity amputees fall at least once in a 12 month period of time. 7 Transfemoral amputees fall 1-3 times in a 60 day period depending on type of prosthetic knee. 6 Selected References Jenkins P et al. Am J Ind Med Patient recall Misunderstanding of the definition of a stumble vs. fall vs. general instability Not a surrogate measure. Directly measures outcome of interest. Recall of Stumbles & Falls Procedure Options to query the number of stumbles and falls include: Calendar marking Journaling Questioning number of stumbles/falls in a given time. Methods for questioning number of stumbles/falls in a given time Over how long of a period are you asking the patient to recall? Less than 3 months is ideal Less than 12 months maintains some level of validity/reliability assuming stable cognition A different assessment should be used beyond 12 months of recall Be sure the patient knows exactly what you are asking them to recall: Define and clarify the difference between a stumble and a fall: 6 A stumble is an event in which you thought you were actually going to fall l to the ground or a lower level but did not A fall is an event in which you unintentionally lost balance and/or stability and landed on the ground or lower level. Activity-specific Balance Confidence Scale (ABC) Non- To objectify self-perceived balance confidence. Specifically, this 16-item questionnaire assesses patient balance confidence in performing various mobility related functional tasks. Maximum score=100 with higher scores indicating increased balance confidence. Scores >80 generally indicate high functioning, active older adults. Mean score for 245 community-dwelling, unilateral amputees was 63.8 Further analysis revealed mean of 54.1 for vascular amputees and 74.7 for traumatic amputees Selected References Powell LE, Myers AM. J Gerontol A Biol Sci Med Sci Miller WC et al. Arch Phys Med Rehabil Includes questions regarding confidence/perceived ability to walk on icy sidewalks which may not be applicable in all regions. -Describes activities (i.e. reaching) in a task-specific, easy to understand manner. -Good reliability shown in patients with amputation. -Good construct validity with TUG test and 2 minute walk test in patients with amputation.

15 Functional Performance Measures related to Fall Risk Assessment Advantages: Repeated Measures of a patient over time to monitor change Reference values available for select fall risk assessments in the literature Objective & Quantifiable : Many are not validated in this population Lack of cut points for fall- risk in this population Reference values are not available for all levels of amputation Evidence-Based Intervention This section provides a glimpse of evidence-based interventions It is not exhaustive as certainly, other interventions exist but currently their efficacy has not been determined scientifically. Intervention In 1997, only 12-16% 16% 35 of those with lower extremity amputation secondary to vascular disease were discharged to an inpatient setting for rehabilitation Regional differences Maryland had 12% Massachusetts had 16% Therefore, rehabilitation and fall prevention, spans multiple different healthcare settings (e.g. inpatient, outpatient, home therapy, long term care)

16 Intervention Multidisciplinary approach 9 Environmental assessment of patient s s room Evaluation/modification of medications Wheelchair skills training program Remember these Intervention 89% of amputees were discharged from rehabilitation with prosthesis when they received: An average of 16.4 therapy sessions (5 to ) Assistive devices (AD) in the following progression: Parallel bars Four-footed walkers Two-wheeled wheeled walkers Two crutches Four-wheeled walkers Two canes One cane The mean number of AD s used was Intervention Falling affects amputees during 8 Transfer Ambulation Thus, a balance training program in addition to fitting the patient with a prosthesis was recommended: 20 min balance training per day x 5 days Balance ReTrainer As a result of the program, the following improved: Standing tolerance TUG Walking speed No indication if falls decreased

17 Intervention Interventions to consider during inpatient rehabilitation: 1. Patient education 2. Environmental modification 3. Stump protector 4. Wheelchair skills training These interventions: Did not reduce the number of falls Did reduce the number of falls that resulted in injuries Intervention As indicated by Miller et al 37, the following are areas related to decreased balance confidence in community dwelling unilaterally involved LE amputees: Mobility device use Need to concentrate while walking in ADL Depression Fear of falling The majority of these areas can be addressed in physical rehabilitation Intervention In anticipation of a slip and fall event, J Yang et al 3 indicate that training the following muscles: Transversus Abdominus & Erector Spinae Rectus Femoris & Biceps Femoris Gluteus Maximus & Gluteus Medius Could provide the following benefits: Slip event detection, prevention and control of falls The most crucial muscle in these roles seems to be the Gluteus Maximus

18 References 1. Ziegler-Graham K, MacKenzie EJ, Ephraim PL, Travison TG, Brookmeyer R. Estimating the prevalence of limb loss in the United States: 2005 to Arch Phys Med Rehabil. 2008;89(3): Dillingham TR, Pezzin LE, Shore AD. Reamputation,, mortality, and health care costs among persons with dysvascular lower-limb limb amputations. Arch Phys Med Rehabil. 2005;86(3): Yang J, Jin D, Ji L, Wang R, Zhang J, Fang X, Zhou D, Wu M. The reaction strategy of lower extremity muscles when slips occur to individuals with trans ns-femoral amputation. J Electromyogr Kinesiol ;17(2): Pauley T, Devlin M, Heslin K. Falls sustained during inpatient rehabilitation after lower limb amputation: prevalence and predictors. Am J Phys Med Rehabil. 2006;85(6): Gooday HM, Hunter J. Preventing falls and stump injuries in lower limb amputees during inpatient rehabilitation: completion of the audit cycle. Clin Rehabil. 2004;18(4): Kahle JT, Highsmith MJ, Hubbard SL. Comparison of nonmicroprocessor knee mechanism versus C-Leg C on Prosthesis Evaluation Questionnaire, stumbles, falls, walking tests, stair descent, and knee preference. J Rehabil Res Dev. 2008;45(1): Miller, WC, Speechley M, Death AB, The prevalence and risk factors of falling and fear of falling among lower extremity amputees. Archives of Physical Medicine and Rehabilitation, (8): p Matjacic Z, Burger H. Dynamic balance training during standing in people with trans- tibial amputation: a pilot study. Prosthet Orthot Int. 2003;27(3): Dyer D, Bouman B, Davey M, Ismond KP. An intervention program to reduce falls for adult in-patients following major lower limb amputation. Healthc Q. 2008;11(3 Spec No.): Kaufman KR, Levine JA, Brey RH, Iverson BK, McCrady SK, Padgett DJ, Joyner MJ. Gait and balance of transfemoral amputees using passive mechanical and microprocessor-controlled controlled prosthetic knees. Gait Posture. 2007; 26(4): References 11. Hafner BJ, Willingham LL, Buell NC, Allyn KJ, Smith DG. Evaluation of function, performance, and preference as transfemoral amputees transition from mechanical to microprocessor control of the prosthetic knee. Arch Phys Med Rehabil. 2007;88(2): NeuroCom International, Inc. Accessed online at on November 15, Bohannon RW. Reference values for the five-repetition sit-to to-stand test: a descriptive meta- analysis of data from elders. Percept Mot Skills. 2006;103(1): Jones CJ, Rikli RE, Beam W. A 30-s s chair stand test as a measure of lower body strength in community-residing older adults. Res Q Exerc Sport 1999;70: Hart-Hughes Hughes S. Balance Assessment Handbook. Accessed online at: Topics/fallstoolkit/index.html fallstoolkit/index.html.. on November 15,, Dite W, Temple VA. A clinical test of stepping and change of direction to identify multiple falling older adults. Arch Phys Med Rehabil, 2002;83(11): Dite W, Connor HJ, CurtisHC.. Clinical identification of multiple fall risk early after unilateral transtibial amputation. Arch Phys Med Rehabil. 2007;88(1): Shumway-Cook A, Brauer S, Woollacott Ml. Predicting the probability of falls in community-dwelling older adults using the timed up and go test. Physical Therapy. 2000; 80: Rose DJ, Jones CJ, Lucchese N. Predicting the probability of falls in community-residing older adults using the 8-foot 8 up and go: A new measure of functional mobility. J Aging Phys Activity. 2002:10: Deathe AB, Miller WC. The L test of functional mobility: measurement ment properties of a modified version of the timed "up & go" test designed for people with lower-limb limb amputations. Phys Ther. 2005;85(7): References 21. Nevitt MC, Cummings SF, Kidd S, Black D. Risk factors for non-syncopal falls. JAMA. 1989;12;261(18): Hurvitz EA, Richardson JK, Werner RA, Ruhl AM, Dixon MR. Unipedal stance testing as an indicator of fall risk among older outpatients. Arch Phys Med Rehabil. 2000;81(5): Duncan,PW,, Weiner DJ, Chandler J, Studenski S. Functional reach: predictive validity in a sample of elderly male veterans. Journal of Gerontology: Medical Sciences. 1992;47(3):M93-M98. M Newton, RA. Validity of the multi-directional reach test: a practical measure of limits of stability in older adults.. J Gerontol A Biol Sci Med Sci. 2001;56(4):M Doane NE, Holt LE. A comparison of the SACH and single axis foot in the t gait of unilateral below-knee amputees. Prosthetics and orthotics international 1983;7(1):33 : Barth DG, Schumacher L, Thomas SS. Gait analysis and energy cost of below-knee amputees wearing six different prosthetic feet. Journal of Prosthetics & Orthotics (JPO) 1992;4(2): Lemaire ED, Fisher FR, Robertson DG. Gait patterns of elderly men with trans-tibial tibial amputations. Prosthetics and orthotics international 1993;17(1): VanSwearingen JM, Paschal KA, Bonino P, Chen T. Assessing recurrent fall risk of community-dwelling, frail older veterans using specific tests of mobility and The Physical Performance Test of function.. J Gerontol A Biol Sci Med Sci. 1998;53:M457-M464. M Hornbrook MC, Stevens VJ, Wingfield DJ, Hollis JF, Greenlick MR, Ory MG. Preventing falls among community-dwelling older persons: results from a randomized trial. Gerontologist. 1994;34(1): Hausdorff JM, Rios DA, Edelberg HK. Gait variability and fall risk in community-living older adults: a 1-year 1 prospective study. Arch Phys Med Rehabil. 2001;82(8):

19 References Additional General References 31. Jenkins P, Earle-Richandson G, Slingerland DT, May J. Time dependent memory decay. Am J Ind Med. 2002;41(2): Powell LE, Myers AM. The Activities-specific specific Balance Confidence (ABC) Scale. J Gerontol A Biol Sci Med Sci Jan;50A(1):M Miller WC, Deathe AB, Speechley M. Psychometric properties of the Activities-specific specific Balance Confidence Scale among individuals with lower-limb limb amputation. Arch Phys Med Rehabil May;84(5): Dillingham TR, Pezzin LE. Rehabilitation setting and associated mortality and medical stability among persons with amputations. Arch Phys Med Rehabil Jun;89(6): Dillingham TR, Pezzin LE. Postacute care services use for dysvascular amputees: a population-based study of Massachusetts. Am J Phys Med Rehabil, (3): : p Kirby, R.L., H.Y. Tsai, and M.M. Graham, Ambulation aid use during the rehabilitation of people with lower limb amputations. Assist Technol,, (2): p Miller WC, Speechley M, Deathe AB. Balance confidence among people with lower-limb limb amputations. Phys Ther. 2002;82(9): Dillingham TR, Pezzin LE, Mackenzie EJ. Discharge destination after dysvascular lower- limb amputations. Arch Phys Med Rehabil. 2003;84(11): Miller WC, Deathe AB, Speechley M, Koval J. The influence of falling, fear of falling, and balance confidence on prosthetic mobility and social activity among individuals with a lower extremity amputation. Arch Phys Med Rehabil. 2001;82(9): Miller WC, Deathe AB, Speechley M. Lower extremity prosthetic mobility: a comparison of 3 self-report scales. Arch Phys Med Rehabil. 2001;82(10): Lee JE, Stokic DS. Risk factors for falls during inpatient rehabilitation. Am J Phys Med Rehabil. 2008;87(5): Hurvitz EA, Richardson JK, Werner RA. Unipedal stance testing in the assessment of peripheral neuropathy. Arch Phys Med Rehabil. 2001;82(2): Bohannon RW. Reference values for the timed up and go test: a descriptive meta-analysis. analysis. J Geriatr Phys Ther. 2006;29(2):64-8.