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Impact of a Four-Session Physical Therapy Program Emphasizing Manual Therapy and Exercise on the Balance and Prosthetic Walking Ability of People with Lower-Limb Amputation: A Pilot Study

Wong, Christopher Kevin PT, PhD, OCS; Varca, Matthew J. DPT; Stevenson, Catharine E. DPT; Maroldi, Nicholas J. DPT; Ersing, Jennifer C. DPT; Ehrlich, Julie E. DPT

Journal of Prosthetics and Orthotics: July 2016 - Volume 28 - Issue 3 - p 95–100
doi: 10.1097/JPO.0000000000000099
CME ARTICLE
Free
CME

Purpose No consensus exists regarding best practice for prosthetic rehabilitation programs after unilateral lower-limb amputation. A program integrating manual therapy with exercise for people using lower-limb prostheses has not been systematically investigated. The objectives of this pilot study were to determine whether a four-session physical therapy program of manual therapy, exercise, and functional training would (1) be feasible for people with lower-limb amputation and (2) produce medium to large effect size changes in balance and walking ability and self-reported prosthetic function.

Methods Five subjects were recruited for this pretest-posttest design pilot study. Outcome measures included self-report scales (Houghton Scale, Prosthetics Evaluation Questionnaire, fear of falling, and Activities-Specific Balance Confidence) and clinical performance assessments: Berg Balance Scale, 2-minute walk test, and timed up and go test. One week after the four-session manual therapy, exercise, and functional training program concluded, measures were reassessed. Effect size d and Wilcoxon P values were calculated.

Results Five subjects (average age, 54.0 years), with unilateral amputations of mixed etiology and level, completed the study without adverse event. Berg Balance Scale (d = 1.7, p < 0.05), timed up and go (d = 1.05, p > 0.05), and 2-minute walk test (d = 1.18, p < 0.05) had large effect size changes.

Conclusions A four-session program of manual therapy, exercise, and functional training proved feasible and increased balance and walking ability in people with lower-limb amputation. Controlled research to determine the effects of manual therapy and exercise in this population appears warranted.

CHRISTOPHER KEVIN WONG, PT, PhD, OCS, is affiliated with the Department of Rehabilitation and Regenerative Medicine, Columbia University Medical Center, New York, New York.

MATTHEW J. VARCA, DPT, CATHARINE E. STEVENSON, DPT, NICHOLAS J. MAROLDI, DPT, JENNIFER C. ERSING, DPT, AND JULIE E. EHRLICH, DPT, were affiliated with the Program in Physical Therapy, Columbia University, New York, New York.

Disclosure: The authors declare no conflict of interest.

This research was supported by grant 1 R49 CE002096 from the National Center for Injury Prevention and Control, Centers for Disease Control and Prevention to the Center for Injury Epidemiology and Prevention at Columbia University. The funding source had no role in the conduct of the study or the reporting of the results. The manuscript contents were solely the responsibility of the authors and its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention.

Correspondence to: Christopher Kevin Wong, PT, PhD, OCS, Columbia University Medical Center, 710 West 168th Street, Neurological Institute, 8th floor, New York, NY 10032; email: ckw7@cumc.columbia.edu

The prevalence of people with amputations is expected to more than double to 3.6 million by 2050, with 40% having had major lower-limb loss.1 After lower-limb amputation, a multitude of individual and clinical factors can impact community mobility and participation outcomes among users of prostheses.2 In a review of 48 studies, balance impairment was identified as the most consistent clinical finding associated with decreased prosthetic function.3 Gait dysfunction persists, with approximately half not achieving a satisfactory level of prosthetic use even after multiple years.4,5

As hospital lengths of stay have decreased for individuals after amputations,6 more prosthetic gait training occurs in outpatient settings. A recent systematic review found that few detailed outpatient rehabilitation programs for users of lower-limb prostheses have been researched.7 Although no best practice consensus approach was determined, rehabilitation programs ranging from specific exercises, balance training, resisted gait training, and indoor and outdoor functional walking have been shown to improve gait performance as assessed by gait speed.7 For instance, a program limited to training balance, the most consistent impairment affecting gait in people with lower-limb amputations,3 has improved both balance and gait speed,8 and a program of only supervised walking has also benefited functional walking.9

Because gait speed is the product of cadence and step length, any factors that influence either will influence gait performance. Both cadence and step length in users of prostheses have been increased through various rehabilitation programs. Cadence increased with large effect sizes after resisted gait training,10 but not after core exercises or functional walking.11 Step length increased after rehabilitation as well, although no clear pattern emerged: step length increased on the prosthetic side after core exercises11 and on the intact side after resisted gait training and functional walking.10

Underlying impairments such as hip joint hypomobility, muscle inflexibility, and weakness can influence cadence and step length and therefore limit gait function.12 Decreased hip extension range of motion can limit step length and, thus, gait speed as well as inhibit hip extensor strength.12 Among people with lower-limb amputations, hip joint flexion contractures are common13 and a likely factor in commonly observed gluteal/hip extension weakness that is a major contributor to activity limitation.14

Stretching for hip muscle flexibility can increase gait speed,15 and mobilizations for hip and sacroiliac joints can improve hip extension range of motion, strength, and gait performance.16 In one case study, an individual with a transfemoral amputation and low back pain improved after receiving lumbopelvic joint manipulations to reduce hip weakness and gait asymmetry, but gait speed was not assessed.17 Regardless of gait performance as measured by speed, person factors such as individual confidence and willingness to access the environment will determine overall prosthetic functional use. A physical therapy program integrating manual therapy and exercise to address joint hypomobility, muscle flexibility, and strength, with functional prosthetic gait training to address balance, confidence, and prosthetic functional use, has not been researched. Such a program may help users of lower-limb prostheses improve their balance, gait, and self-reported function in daily activities.

The objectives of this pilot study were to determine whether a physical therapy program of manual therapy, exercise, and functional training would (1) be feasible for people with lower-limb amputation and (2) produce changes of medium to large effect sizes in balance and walking ability or subjective self-report measures after the four-session month-long program.

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METHODS

This study was conducted in accordance with the protocol approved by the Columbia University Medical Center Institutional Review Board.

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SUBJECTS

Community-dwelling adults of any sex and race with any amputation etiology were recruited from support groups by the recreational therapist study coordinator who obtained informed consent. All subjects had completed initial prosthetic rehabilitation and used unilateral transtibial or transfemoral prostheses at home. A total of six 1-hour outpatient sessions over 6-week periods during one fall season were scheduled. A total of five subjects older than 18 years and of any sex and race were recruited for inclusion. People with bilateral and partial foot or hip disarticulation amputations or medical issues preventing independent ambulation were excluded.

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DESIGN

The first (1) and last (6) sessions in this pretest-posttest design study were assessments conducted by one occupational therapist. Between assessments, subjects received four once-per-week interventions during sessions 2 to 5 with an orthopedic certified physical therapist. No home exercise or instructions were provided for the subjects between sessions. Treatments and assessments were conducted in separate buildings without study-related communication. The treatment therapist was blind to subject assessment performances. All therapists were licensed and met as a team and individually with the primary investigator before and during the study to ensure protocol adherence.

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MEASUREMENT

On the first session, subjects provided medical histories and completed the self-reported Houghton Scale (HS), Prosthetics Evaluation Questionnaire (PEQ), numeric fear of falling, and Activities-Specific Balance Confidence (ABC) Scale and performance-based Berg Balance Scale (BBS), 2-minute walk test (2MWT), and timed up and go (TUG) measures in the order presented. The self-report scales and performance-based measures were reevaluated, with updated medical history on the final sixth session.

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SELF-REPORT SCALES

The HS and PEQ mobility subscale (PEQ-MS) assessed prosthetic functional use. The HS quantifies daily prosthesis wear and indoor/outdoor prosthetic use in several walking conditions with four questions, with total scores ranging from 0 to 12.18 The HS has moderate internal consistency (r = 0.70)19 and excellent test-retest reliability (intraclass correlation coefficient [ICC], 0.85–0.96)19,20 and is responsive to change after rehabilitation (p < 0.01, d = 0.60).19 The PEQ-MS also quantifies walking and mobility in various daily activities with test-retest reliability (ICC, 0.85).21 The 12-question, five-level PEQ-MS format in this study has excellent reliability and validity as shown in a Rasch analysis of the 13- and 12-question versions (person-separation reliability, 0.95; item-separation reliability, 0.98; Cronbach α = 0.96).22 Scores on the HS and PEQ correlate moderately with TUG and 2MWT walking ability measures (r = 0.50–0.60).20

The ABC subjectively assessed balance confidence in 16 daily tasks,23 which has excellent test-retest reliability and internal consistency in multiple formats for people after amputation (ICC, 0.99; Cronbach's α = 0.95).24,25 A single numeric rating scale subjectively assessed fear of falling.26 Balance confidence has moderate concurrent validity with balance ability assessed with the BBS (r = 0.63).27 The BBS, with demonstrated reliability (ICC > 0.94)27,28 and validity in people with lower-limb amputations (person-separation reliability = 0.88, item-separation reliability = 0.96, Cronbach's α = 0.83),29 assessed performance-based balance on 14 tasks with a maximal total score of 56.30

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PERFORMANCE-BASED MEASURES

Gait was assessed with the TUG and 2MWT, which both correlate with other assessments including the ABC,24 BBS,27 HS, and PEQ.20 Timed up and go times assessed functional gait by incorporating sit-to-stand from a chair without arms, walking 10 feet and returning, and stand to sit with excellent reliability (ICC, 0.88–0.96).4,21 The 2MWT combines walking ability and exercise capacity and has excellent reliability with responsiveness to change in prosthetic users (ICC, 0.83–0.99).21,31

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INTERVENTION

All subjects received the same specific treatments in hour-long intervention sessions, including manual therapy, exercise, balance, and functional prosthetic mobility training—with rest periods.

Manual therapy including grade III to IV hip mobilizations of the extended residual limb side hip and sacrum was performed with subjects positioned in prone without their prosthesis.16,32,33 The physical therapist then performed mobilization with movements by applying sustained anterolateral pressure to the residual limb side sacroiliac joint while the subject pressed up with both arms while in prone with the sound limb flexed off the table, foot on the floor, and pelvis on the table.4,34 Subjects exhaled then pressed up further to increase hip and lumbopelvic extension through contract-relax muscle energy technique for five repetitions.35

Specific exercise included hip flexor stretching, gluteal and abdominal stabilization exercises, and static and dynamic balance activities. Hip flexor self-stretching was performed in the mobilization with movement position for 30 seconds and three repetitions to reduce anticipated hip flexor contractures,13 increase stride length and gait speed,15,36 and improve balance.8 Stabilization muscle exercises were performed for 20 to 30 seconds for five repetitions and a total duration of approximately 2 minutes for abdominal and gluteal muscle activation to counter anticipated hip weakness.14 Core and gluteal muscle activation through stabilization exercises in non-weight bearing11 and weight bearing resisted gait training has improved prosthetic gait speed.10

Functional prosthetic mobility training included 20 sit-to-stand repetitions, which correlates with overall hip strength.14 Static and dynamic balance training alone has also increased gait speed,37 and subjects performed the balance activities rated most difficult among BBS tasks for people with lower-limb loss (one foot in front, placing alternating feet on an 8-in stool, and turning in a circle).29 Supervised walking alone can increase prosthetic gait speed,9,10 with a minimum of 2 minutes used to develop exercise capacity. Functional training included turns and other walking variations.38

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FEASIBILITY

Because of the paucity of published reports of joint mobilization in the population of people with lower-limb amputations, feasibility was determined based on two criteria: (1) a minimum 75% completion rate for enrolled subjects and (2) no adverse events related to joint mobilization.

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STATISTICAL ANALYSIS

Results were reported in relation to standard error of the measurement (SEM) and minimal detectable change (MDC), respectively, for TUG (1.6 and 3.6 seconds), 2MWT (48.5 and 112.5 m), and PEQ (0.3 and 0.8) as available for people with lower-limb amputation.21 Indicators of responsiveness to change included the 2-point minimal clinically important difference (MCID) for improved BBS was based on findings for community elderly39; improved 2MWT distance was based on people with amputations,31 and Cohen d effect sizes were calculated (large, d ≥ 0.8; medium, 0.8 ≥ d ≥ 0.5).40 A medium effect size, conceived as change substantial enough to be clinically observable,40 was considered the minimum change required; effect sizes will be used to calculate projected sample size in a larger follow-up study. Nonparametric Wilcoxon signed-rank tests were used to assess the significance of posttreatment changes (α = 0.05) due to an anticipated small and heterogeneous subject sample. All statistical analysis was performed with SPSS 22.0.

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RESULTS

All five subjects, with average age of 54.0 years, unilateral amputations of mixed etiology (80% vascular) and level (80% transtibial, 20% transfemoral), and an average 3 years of wearing prostheses, completed the pilot study (see Table 1). All five had improved balance (BBS) and walking ability (2MWT) after the 4-week manual therapy, exercise, and functional training intervention program (see Table 2). Large effect size improvements were observed for fear of falling, BBS, and both walking ability measures. Balance and walking distance demonstrated significant changes (see Table 3).

Table 1

Table 1

Table 2

Table 2

Table 3

Table 3

Improvements on the BBS for all subjects exceeded the MCID.39 The 2MWT improvements exceeded past reported standard error measurements,21 but not the MDC for 2MWT.31 Whereas TUG time improvements for three of five subjects exceeded the SEM, only one subject improved beyond the MDC. All subjects reported improvements on the PEQ that exceeded the SEM and MCD.21 One of two subjects who did not start at the satisfactory community-walking level (HS < 9) improved to the community-walking level18 (see Table 3).

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DISCUSSION

After a four-session intervention incorporating manual therapy, exercise, and balance and functional prosthetic training, the large effect size improvement for gait speed was greater than reported for non–weight-bearing core stabilization exercises,11 balance training,8 and supervised walking9 and less than 10 sessions of resisted gait10 and 10 months of functional gait training.38 Improvements in walking (2MWT) and balance ability (BBS) were clinically important. The study intervention appeared feasible, with all subjects completing the study on time without adverse events and medium or larger effect sizes observed. Future research using comparison conditions are required to determine whether the pilot intervention will provide benefits beyond other approaches.

The overall concept of the study intervention was grounded in the International Classification of Functioning Disability and Health perspective of integrated body structures, functions, and activities.41 Study interventions were designed to strategically address specific body function impairments common in people with lower-limb amputation that contribute to activity limitations: decreased hip extension range of motion,42 gluteal weakness,14 balance impairment,29 and functional prosthetic turning deficits.43,44

The sequence of specific interventions was guided by the spinal stability model proposed by Panjabi,45 popularized by Lee,46 and expanded to include movement by Hoffman.47 Briefly summarized, when passive joint structures either (a) insufficiently stabilize or (b) excessively restrict normal movement, active muscular structures deviate from the normal pelvic stability and hip mobility functions—observed as weakness and dysfunctional movement.47 For example, a hypomobile hip joint limits hip extension range of motion and inhibits hip extensor muscle activation; thus, lumbar muscles provide compensatory extension at lumbosacral joints—observed as excessive anterior pelvic tilt and lumbar lordosis typical in dysfunctional prosthetic gait.37

Passive hip joint mobility may be the linchpin of subsequent gait dysfunction.48 Manual therapy to reduce hip flexion contracture, hip extension weakness, and impaired gait performance is not novel but appears uncommon in the treatment of people with lower-limb amputation. Whereas individual clinicians may use manual therapy on a case-by-case basis,17,48 typical treatment emphasizes functional training without specifically addressing underlying joint impairments that contribute to functional deficits.7

In this study, gait and balance performance improved after all subjects received four treatment sessions that included hip, sacrum, and sacroiliac joint mobilizations—with no adverse events occurring. Subjects also performed exercise, balance, and gait training as in a variety of past rehabilitation programs,7 but the effect size changes observed after the study program including manual therapy were larger than in past studies except for those that lasted more than twice as long.10,38 The results of this study may encourage physical therapists to use the full spectrum of their skills and researchers to study treatment approaches that include impairment of passive and active structures that contribute to limitations in functional movement and activity participation.

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LIMITATIONS

This pilot study determined effect size changes for a four-session 1-month intervention. The pre-post study design was conceived to meet all methodological quality criteria for single group designs,49 except for a sufficient follow-up period. Further study with a larger sample and two-group design is required to determine effectiveness beyond the five subjects. Without a comparison group, no relative merit can be assigned to any specific aspect of the study intervention and no cause and effect can be confirmed. Alternately, a pragmatic research approach with interventions individualized according to indication would provide insight into individual responses. In addition, the inclusion criteria included multiple amputation levels and etiologies and did not specify medications or other specific comorbidities. Furthermore, test order was consistent throughout and could have influenced results. This pilot study did, however, control environment, assessment and treatment therapist blinding, and BBS tester reliability, although outcome assessment was not randomized. Reliability of the TUG and 2MWT was not assessed because time-based measures have been reliable without special training.4

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CONCLUSION

This pilot study described a physical therapy program of manual therapy, exercise, and functional prosthetic training for improving balance and walking ability in people with lower-limb loss. The study results suggest that significant improvements with large effect sizes for balance and gait performance can be obtained within a 4-week intervention period. Future controlled research appears warranted.

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ACKNOWLEDGMENTS

We thank physical therapist Brian Gugliuzza, occupational therapist Matthew Ganulin, and recreational creative-arts therapist Jacqueline Callender for their efforts in support of this study.

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Keywords:

Berg balance scale; exercise; functional mobility; gait; limb loss; lower-limb; manual therapies; prosthesis; 2-minute walk test

© 2016 by the American Academy of Orthotists and Prosthetists.