The L Test of Functional Mobility:Measurement Properties of aModified Version of the Timed“Up & Go” Test Designed for PeopleWith Lower-Limb AmputationsBackground and Purpose. Walk tests provide essential outcome infor-mation when assessing ambulation of individuals with lower-limbamputation and a prosthetic device. Existing tests have limitations suchas ceiling effects or insufficient challenge. The objective of this studywas to assess the reliability and validity of data for a clinical measure ofbasic mobility, the L Test of Functional Mobility (L Test). Subjects. Forthis methodological study, 93 people with unilateral amputations (74%transtibial, 26% transfemoral; 78% male, 22% female; mean age⫽55.9years) were consecutively recruited from an outpatient clinic. Twenty-seven subjects returned for retesting. Methods. To assess concurrentvalidity, subjects completed the L Test, Timed “Up & Go” Test (TUG),10-Meter Walk Test, and 2-Minute Walk Test, followed by the Activities-specific Balance Confidence scale, Frenchay Activities Index (FAI),and mobility subscale of the Prosthetic Evaluation Questionnaire(PEQ-MS). Amputation cause and level, walking aid use, automaticstepping, and age variables were used to assess discriminant validity.Results. Intraclass correlation coefficients were .96 for interrater reli-ability and .97 for intrarater reliability, and minimal bias existed uponretesting. The magnitude of concurrent validity correlations (r) wasvery high between the L Test data and data for other walk tests and fairto moderate between the L Test data and data for self-report measures.The L Test discriminated between all groups as hypothesized. Discus-sion and Conclusion. The L Test is a 20-m test of basic mobility skillsthat includes 2 transfers and 4 turns. It demonstrated excellentmeasurement properties in this study. [Deathe AB, Miller WC. The LTest of Functional Mobility: measurement properties of a modifiedversion of the Timed “Up & Go” Test designed for people withlower-limb amputations. Phys Ther. 2005;85:626–635.]Key Words: Ambulation, Amputation, Outcome measure, Reliability, Validity.A Barry Deathe, William C Miller626 Physical Therapy . Volume 85 . Number 7 . July 2005Research Report䢇ўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўThe need for measures of outcome in health careis well-recognized,1yet no consensus exists as towhat outcome should be emphasized or whichtool should be used in rehabilitation for indi-viduals who have a lower-extremity amputation.2One ofthe primary goals of rehabilitation programs for peoplewith a lower-extremity amputation is to assist them inreturning to and maintaining normal living activitieswith prosthetic devices. To monitor program success, itis therefore necessary to evaluate the skills required formobility using prosthetic devices. According to theWorld Health Organization, the ability to change bodyposition and the ability to walk are key components ofmobility.3In general, basic mobility using prostheticdevices should allow safe household ambulation, andincludes the skill set of transfers, level walking, andturns.Performance walk tests used in rehabilitation with aprosthetic device include measures of fixed walkingtime, such as the 2-Minute Walk Test,4and measures offixed walking distance, such as the Timed “Up & Go”Test (TUG),5the 10-Meter Walk Test,6and gradations ofa 100-m walk.7Studies8,9have shown that objectiveperformance-oriented tests have excellent measurementproperties and are able to predict future function.In our Regional Amputee Program, we use the TUG andthe 2-Minute Walk Test to assess inpatient and outpa-tient prosthetic training. We have observed a ceilingeffect with respect to the short version of the TUG (6-mtotal distance), particularly for elderly people who aremore fit and for younger people with amputations. Thelonger 2-Minute Walk Test, however, is difficult toadminister in the outpatient clinic setting, given that a20-m hallway that is relatively free of other patients andstaff is needed and given that clinics are required toconduct the test without distraction. Therefore, ourneed was to find or develop a test that could be easilyand quickly administered concurrent with each patientvisit that assisted with determining ability to walk withprosthetic devices. Our preference was to retain thetransfer skill set of the TUG. Observation of a patient’sgait during clinics showed that we usually asked thepatient to get up and walk out of the room, turn and godown the hall, then return to the room and sit down.This walking path, representing an “L” configuration,required turns to both the right and the left. Standard-izing the distance (3 ⫻ 7 m) led to the development ofa potentially more demanding, yet practical, modifica-tion of the TUG that we have titled the L Test ofFunctional Mobility (L Test).We believe that the L Test may be a useful indicator ofmobility that will distinguish change in status for notonly older people with amputations who are moredisabled and have frail health, but also for fit older andyounger individuals who are less disabled. The objectivesof this study were to assess the reliability and the validityof data obtained with the L Test.MethodDesign/ParticipantsA total of 102 subjects attending their regularly sched-uled appointment between June and December 2001who met the study criteria were consecutively sampledfrom the regional outpatient clinic for people withamputations. To be included, subjects had to be olderthan 19 years of age, have a unilateral transtibial (TT) ortransfemoral (TF) amputation related to vascular ortraumatic etiology, and have had their prosthesis aminimum of 6 months. Subjects were excluded if theywere unable to speak or read English or follow verbalAB Deathe, BSc, MD, FRCP(C), is Associate Professor, Faculty of Medicine, Department of Physical Medicine and Rehabilitation, and MedicalDirector, SouthWestern Ontario Amputee Program, St Joseph Health Centre, University of Western Ontario, Parkwood