Potentially inappropriate medication use among older adults with lower-limb loss.

OBJECTIVE: The aim of this study was to evaluate the prevalence of, and explore factors related to, prescription of potentially inappropriate medications (PIMs) among older adults with lower-limb loss (LLL). METHODS: This was a secondary analysis of a cross-sectional dataset collected through an interdisciplinary limb loss clinic between September 2013 and November 2022. Self-report medication lists were reviewed during in-clinic face-to-face interviews and compared to the American Geriatrics Society Beers Criteria corresponding to the patient's evaluation year. RESULTS: Of 82 participants (72.9 ± 6.6 years-old; 78.0 % male), n = 41 (50.0 %) reported using one or more PIM. PIM prescription was significantly associated with presence of phantom limb pain, history of upper gastrointestinal issues, and a greater number of medications. DISCUSSION: Polypharmacy and PIM use are common among older adults with LLL. Greater attention should be paid to medications post-amputation, especially pain management medications, to minimize potential adverse side-effects.

Risk Factors for Underreporting of Life-Limiting Comorbidity Among Adults With Lower-Limb Loss.

Peripheral neuropathy (PN) and peripheral arterial disease (PAD) are life-limiting comorbidities among adults with lower-limb loss that may not be adequately addressed in current care models. The objective of this study was to evaluate underreporting of PN and PAD among adults with lower-limb loss. We conducted a secondary analysis of a cross-sectional dataset of community-dwelling adults with unilateral lower-limb loss seen in an outpatient Limb Loss Clinic (n = 196; mean age = 56.7 ± 14.4 years; 73.5% male). Individuals participated in standardized clinical examinations including Semmes-Weinstein monofilament testing to assess for PN and pedal pulse palpation to assess for PAD. Bivariate regression was performed to identify key variables for subsequent stepwise logistic regression to discern risk factors. Clinical examination results indicated 16.8% (n = 33) of participants had suspected PN alone, 15.8% (n = 31) had suspected PAD alone, and 23.0% (n = 45) had suspected PN and PAD. More than half of participants with clinical examination findings of PN or PAD failed to self-report the condition (57.7% and 86.8%, respectively). Among adults with lower-limb loss with suspected PN, participants with dysvascular amputations were at lower risk of underreporting (odds ratio [OR] = 0.2, 95% CI: 0.1-0.6). For those with suspected PAD, those who reported more medication prescriptions were at lower risk of underreporting (OR = 0.8, 95% CI: 0.7-1.0). Adults with lower-limb loss underreport PN and PAD per a medical history checklist, which may indicate underdiagnosis or lack of patient awareness. Routine assessment is highly recommended in this population and may be especially critical among individuals with non-dysvascular etiology.

Key Modifiable Factors in Community Participation Among Adults With Lower Limb Amputation.

OBJECTIVE: The aim of the study is to identify factors that may predict community participation among adults with lower limb amputation. DESIGN: This study is a secondary analysis of a cross-sectional data set, including 126 community-dwelling adults, ≥1 yr after unilateral transfemoral- ( n = 44; mean age = 59 ± 14 yrs) or transtibial-level amputation ( n = 82; mean age = 59 ± 14 yrs) seen in an outpatient limb loss clinic. Participation was assessed with the Community Integration Questionnaire. Factors, that is, demographics, comorbidities, prosthesis use per the Houghton Scale, Socket Comfort Score, assistive device use, falls history, and activity level per General Practice Physical Activity Questionnaire were evaluated. Moreover, balance confidence per the Activities-Specific Balance Confidence Scale, mobility per the Locomotor Capabilities Index, fast and self-selected gait speed per 10-meter walk tests, and functional mobility via Timed Up and Go were also included. RESULTS: Community participation was correlated with several factors ( P ≤ 0.050). Stepwise regression of correlated factors found absence of peripheral neuropathy and greater self-reported physical activity, balance confidence, and prosthesis use, as the strongest correlates, collectively explaining 50.1% of the variance in community participation post-lower limb amputation. CONCLUSIONS: Findings identify key modifiable factors for consideration in future prospective research seeking to enhance community reintegration and participation among adults living with a unilateral transfemoral- or transtibial-level amputation.

Post-amputation pain: Comparing pain presentations between adults with and without increased amputated-region sensitivity.

OBJECTIVE: Among adults with persistent post-amputation pain, increased amputated-region pain sensitivity may reflect peripheral sensitization or indicate underlying central sensitization. To determine whether underlying central sensitization may contribute to increased pain sensitivity in this population, this study compared clinical signs and symptoms associated with central sensitization between adults with post-amputation pain who demonstrate or lack increased amputated-region sensitivity (as compared to reference data). DESIGN: Cross-sectional. SUBJECTS: Ninety-nine adults (60 with a unilateral, transtibial amputation and post-amputation pain, 39 pain-free controls with intact limbs). METHODS: Participants underwent pain-pressure threshold testing of amputated-region and secondary (non-amputated region) sites and completed outcome measures assessing central sensitization symptoms (Patient-Reported Outcomes Measurement Information System® pain intensity and interference domains, Central Sensitization Inventory). Among the full sample, the presence and frequency of specific central sensitization symptoms were evaluated. Participants with post-amputation pain were then grouped based on whether normalized, amputated-region pain-pressure thresholds fell below (i.e., sensitive) or above (i.e., non-sensitive) the 25th percentile of sex-specific reference data. Between-group differences in normalized secondary-site sensitivity were evaluated using a multivariate analysis of variance; central sensitization symptom scores were compared using a Kruskal-Wallis test. RESULTS: Noteworthy symptoms associated with central sensitization (e.g., fatigue, sleep disturbance, cognitive difficulty) were reported by 33%-62% of participants. Secondary-site pain sensitivity was greater among individuals with increased amputated-region sensitivity (n = 24) compared to peers without increased amputated-region sensitivity ([n = 36], mean difference > 1.33 standard deviation [SD], p < 0.001). Central sensitization symptom scores, however, were similar between groups (p > 0.187). CONCLUSIONS: Participants with increased amputated-region sensitivity demonstrate generalized, secondary-site pain hypersensitivity, potentially indicating underlying central sensitization. Central sensitization symptom scores, however, were similar between groups, suggesting differences in physiological pain sensitivity may not manifest in subjective post-amputation pain descriptions.

Body image and perception among adults with and without phantom limb pain.

BACKGROUND: Following lower-limb amputation, phantom limb pain (i.e., pain perceived as coming from the amputated portion of the limb) is common. Phantom limb pain may be associated with impaired body image and perception, which may be targets for rehabilitative intervention. OBJECTIVE: To compare measures of body image and perception between adults with and without phantom limb pain post amputation and evaluate associations between measures of body image and perception and phantom limb pain. DESIGN: Survey. SETTING: Online, remote assessment. PARTICIPANTS: Seventy-two adults ≥1 year post unilateral lower-limb loss (n = 42 with phantom limb pain, n = 30 without phantom limb pain or pain in the remaining portion of the limb). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Self-reported outcome measures assessing body image (i.e., Amputee Body Image Scale-Revised), perceptual disturbances associated with the phantom limb (i.e., a modified Bath Complex Regional Pain Syndrome Body Perception Disturbance Scale), and prosthesis satisfaction (i.e., Trinity Amputation and Prosthesis Experience Scale) were administered; participants with phantom limb pain reported pain interference via the Brief Pain Inventory-Short Form. Between-group comparisons of self-reported outcome measure scores were conducted using Mann Whitney U or chi-square tests, as appropriate (a = .05). RESULTS: Compared to peers without phantom limb pain, adults with phantom limb pain reported more negative body image; increased phantom limb ownership, attention, and awareness; and reduced prosthesis satisfaction and embodiment (U = 175.50-364.00, p < .001 to .034). Disturbances in phantom limb perception (i.e., size, weight, pressure, temperature) were similar between groups (p = .086 to >.999). More negative body image was associated with increased phantom limb pain interference (τb  = .25, p = .026). CONCLUSIONS: Adults with phantom limb pain demonstrate more negative body image and hypervigilance of the phantom limb as compared to peers with nonpainful phantom sensations. Mind-body treatments that target impaired body image and perception may be critical interventions for adults with phantom limb pain.

Pain, Balance-Confidence, Functional Mobility, and Reach Are Associated With Risk of Recurrent Falls Among Adults With Lower-Limb Amputation.

Objective: The study evaluated whether pain intensity and extent, balance-confidence, functional mobility, and balance (eg, functional reach) are potential risk factors for recurrent falls among adults with a lower-limb amputation. Design: Cross-sectional study. Setting: Research laboratory. Participants: Eighty-three adults with unilateral lower-limb amputation that occurred >1 year prior (26 transfemoral- and 57 transtibial-level amputation; 44.6% women; 51.8% traumatic cause of amputation; N=83). Intervention: Not applicable. Main Outcome Measures: Participants reported on the number of falls in the past year, as well as pain intensity in the low back, residual, and sound limbs. Balance-confidence (per the Activities-Specific Balance-Confidence Scale [ABC]), functional mobility (per the Prosthetic Limb Users Survey of Mobility ([PLUS-M]), and balance (per the Functional Reach and modified Four Square Step Tests) were obtained. Results: After considering non-modifiable covariates, greater extent of pain, less balance-confidence, worse self-reported mobility, and reduced prosthetic-side reach were factors associated with recurrent fall risk. Adults reporting pain in the low back and both lower-limbs had 6.5 times the odds of reporting recurrent falls as compared with peers without pain. A 1-point increase in ABC score or PLUS-M T score, or 1-cm increase in prosthetic-side reaching distance, was associated with a 7.3%, 9.4%, and 7.1% decrease in odds of reporting recurrent falls in the past year, respectively. Conclusions: Of the 83 adults, 36% reported recurrent falls in the past year. Presence of pain in the low back and both lower-limbs, less balance-confidence, worse PLUS-M score, and less prosthetic-side reaching distance were identified as modifiable factors associated with an increased odd of recurrent falls.

Clinical mobility metrics estimate and characterize physical activity following lower-limb amputation.

BACKGROUND: Regular physical activity following a lower-limb amputation is essential for maintaining health and a high quality of life. Most adults with a lower-limb amputation, however, participate in insufficient daily physical activity, and thus, are predisposed to poor health outcomes. Estimating physical activity after lower-limb amputation via common mobility metrics may aid in clinical decisions regarding treatment prioritization and prosthesis prescription. The objectives of this study were (a) to examine associations between daily physical activity and patient-reported and performance-based mobility metrics among adults with lower-limb amputation, and (b) to determine whether patient-reported and performance-based mobility metrics can distinguish between physical activity status [i.e., sedentary (< 5000 steps/day) or non-sedentary (≥ 5000 steps/day)] of adults with lower-limb amputation. METHODS: A cross-sectional study involving 35 adults with a unilateral transtibial (N = 23; 63.0 ± 10.4 years) or transfemoral amputation (N = 12; 58.8 ± 9.5 years) was conducted. Participants completed patient-reported (Prosthesis Evaluation Questionnaire-Mobility Subscale) and performance-based mobility metrics (L-Test, 10-m Walk Test, 6-min Walk Test). Physical activity, i.e., average steps/day, was measured with an accelerometer. RESULTS: Patient-reported and performance-based mobility metrics were associated with daily physical activity (p < 0.050). Prosthesis Evaluation Questionnaire-Mobility Subscale scores, L-Test time, 10-m Walk Test speed and 6-min Walk Test distance independently explained 11.3%, 31.8%, 37.6% and 30.7% of the total variance in physical activity. Receiver operating characteristic curves revealed patient-reported and performance-based mobility metrics significantly distinguish between physical activity status, i.e., sedentary (< 5000 steps/day) versus non-sedentary (≥ 5000 steps/day). Preliminary cut-points for mobility metrics to classify physical activity status were determined. CONCLUSIONS: Following a lower-limb amputation, patient-reported and performance-based mobility metrics may estimate daily physical activity, thereby aiding clinical decisions regarding treatment prioritization as well as prosthesis selection.

Characterizing Pain Among Adolescents and Young Adults With Arthrogryposis Multiplex Congenita.

PURPOSE: Primary study objectives were to ( a ) characterize pain and explore differences between adolescents and adults with arthrogryposis multiplex congenita (AMC) and ( b ) evaluate associations between pain-related outcomes and mobility. METHODS: People who can walk and with AMC completed pain-related questionnaires. RESULTS: Sixty-three participants (28 adolescents and 35 young adults) were recruited. Pain was reported in the past week by 81% of participants; intensity ratings were similar between age groups. Per the McGill Pain Questionnaire, pain severity was significantly lower among adolescents. Adults had a greater number of painful regions compared with adolescents. Greater 7-day average pain intensity, McGill Pain Questionnaire scores, and number of painful regions were associated with reduced functional mobility. CONCLUSIONS: As most adolescents and young adults with AMC have at least mild pain, and pain is associated with mobility, future longitudinal investigations of pain and its functional consequences are warranted.

Adults with unilateral lower-limb amputation: greater spatial extent of pain is associated with worse adjustment, greater activity restrictions, and less prosthesis satisfaction.

OBJECTIVES: This study's primary purpose was to determine if the extent of bodily pain, as evaluated with pain body diagrams, is associated with prosthetic-related activity restrictions, adjustment, and satisfaction among adults with a major unilateral lower-limb amputation. A secondary objective was to evaluate between-days, test-retest reliability for pain body diagrams among adults with lower-limb amputation. METHODS: Adults with a lower-limb amputation that occurred ≥1 year prior participated in an online, cross-sectional research study. Outcome measures included pain body diagrams and the Trinity Amputation and Prosthesis Experience Scales-Revised, which evaluates post-amputation activity restrictions, psychosocial adjustment, and prosthesis satisfaction. Linear regression modeling was used to evaluate associations between the number of painful body regions and prosthetic outcomes, after considering covariates (alpha ≤ 0.010). A subset of participants recompleted pain body diagrams to evaluate between-days, test-retest reliability. RESULTS: Data from 74 participants (n = 32 female; n = 42 transtibial-level; n = 27 traumatic etiology) were available. Beyond covariates (i.e., age, sex, amputation level), the total number of painful body regions was significantly associated with all Trinity Amputation and Prosthesis Experience Scales-Revised subscales (p < 0.001-0.006), with the exception of Social Adjustment (p = 0.764). The total number of painful body regions explained 14.5, 11.8, 11.6, and 7.4% of the variance in Functional Satisfaction with the Prosthesis, Adjustment to Limitation, General Adjustment, and Activity Restriction, respectively. In a subset (n = 54), test-retest reliability for total number of painful body regions per body diagrams was good [intraclass correlation coefficient (ICC)3,1 = 0.84]. CONCLUSIONS: A greater number of painful body regions is associated with greater activity restriction, worse adjustment, and lower prosthesis satisfaction, supporting the need to enhance post-amputation pain management and both amputated- and secondary-site pain prevention. ETHICAL COMMITTEE NUMBER: IRB #1611862.

Test-retest reliability for performance-based outcome measures among individuals with arthrogryposis multiplex congenita.

BACKGROUND: Most individuals with arthrogryposis multiplex congenita, a rare condition characterized by joint contractures in ≥ 2 body regions, have foot and ankle involvement leading to compromised gait and balance. The purpose of this study was to establish between-days, test-retest reliability for performance-based outcome measures evaluating gait and balance, i.e., the 10-m Walk Test, Figure-of-8 Walk Test, 360-degree Turn Test, and modified Four Square Step Test, among adolescents and adults with arthrogryposis multiplex congenita. METHODS: This reliability study included ambulatory participants, aged 10 to 50 years, with a medical diagnosis of arthrogryposis multiplex congenita. Participants completed performance-based measures, in a randomized order, on two separate occasions. Intraclass correlation coefficients with 95% confidence intervals and minimal detectable changes at the 90% and 95% confidence level were calculated. RESULTS: Participants included 38 community-ambulators with a median of 13 out of 14 upper and lower joint regions affected. Intraclass correlation coefficient point estimates and 95% confidence intervals ranged from .85-.97 and .70-.98, respectively. Minimal detectable changes were 10 to 39% of sample means and were largest for the modified Four Square Step Test. CONCLUSIONS: Among individuals with arthrogryposis, gait speed per the 10-m Walk Test, as well as non-linear walking and dynamic balance assessment per the Figure-of-8 Walk and 360 Degree Turn Tests, have adequate test-retest reliability enabling evaluation of individual patient changes. Changes in groups of ambulatory individuals with arthrogryposis multiplex congenita may be reliably evaluated with all of the studied outcome measures.

Time Since Lower-Limb Amputation: An Important Consideration in Mobility Outcomes.

OBJECTIVE: The aim of this study was to evaluate associations between time since amputation (TSAmp) and mobility outcomes of adults with lower-limb amputation. DESIGN: A secondary analysis of a cross-sectional dataset, including 109 community-dwelling adults, 1 yr or more after unilateral transfemoral (n = 39; mean age, 54 ± 15 yrs) or transtibial (n = 70; mean age = 58 ± 14 yrs) amputation, was conducted. Participants attended standardized clinical evaluations and completed mobility-related outcome measures: Prosthesis Evaluation Questionnaire-Mobility Subscale, timed up and go, 10-m walk test, and 6-min walk test. RESULTS: After controlling for age, sex, amputation level, and etiology, TSAmp was significantly associated with each mobility outcome. Prosthesis Evaluation Questionnaire-Mobility Subscale and TSAmp were linearly associated, with TSAmp explaining 10.6% of the overall variance. Timed up and go test time and TSAmp were linearly associated, with TSAmp and an interaction term (LevelxTSAmp) explaining 8.4% of the overall variance; 10-m walk test speed and 6-min walk test distance had nonlinear associations with TSAmp, with TSAmp and nonlinear terms (TSAmp2) explaining 12.1% and 13.2% of the overall variance, respectively. CONCLUSIONS: Based on the findings, longer TSAmp may be associated with better Prosthesis Evaluation Questionnaire-Mobility Subscale score and timed up and go test time, whereas longer TSAmp may be associated with better or worse 10-m walk test speed and 6-min walk test distance depending upon time elapsed since lower-limb amputation. Estimations of postamputation mobility among adults with lower-limb amputation should consider TSAmp.

Sex-specific Differences in Multisite Pain Presentation among Adults with Lower-Limb Loss.

OBJECTIVES: Multisite pain remains significantly understudied following lower-limb loss (LLL), especially among females. This study aimed to explore sex-specific differences in the presentation of multisite pain post LLL. Hypotheses were multisite pain would be more prevalent among females post LLL as compared with males, and female sex would be significantly associated with multisite pain prevalence. METHODS: In this cross-sectional study, participants answered standardized questions regarding the presence of amputation-specific (ie, phantom-limb, residual-limb) and secondary (ie, contralateral-limb, low-back) pain. Multisite pain was defined as pain in ≥ 2 locations. Sex-specific differences in pain prevalence were evaluated using chi-square tests (P ≤ 0.050). Using logistic regression, the association between sex and multisite pain was examined after controlling for covariates (age, body mass index, time since amputation, amputation etiology and level). RESULTS: The sample included 303 adults (33% females) ≥ 1 year post unilateral LLL. More females than males reported pain in the residual limb (53.0% vs. 38.4%), low back (56.0% vs. 39.9%), contralateral knee (37.0% vs. 24.1%), and contralateral hip (25.0% vs. 12.3%; P < 0.050). More females than males were classified as having multisite pain (72.0% vs. 54.7%; P = 0.004). While patterns of multisite pain were similar (ie, pain affected both amputation-specific and secondary sites) between sexes, being female was independently associated with higher odds of having multisite pain (odds ratio: 2.40, 95% confidence interval: 1.40 to 4.12). DISCUSSION: Female sex appears to be associated with multisite pain ≥ 1 year after LLL. Future work is needed to identify mechanisms underlying sex-specific differences in pain presentation and evaluate the impact of sex on pain-related outcomes post amputation.

Balance-confidence is associated with community participation, perceived physical mobility, and performance-based function among individuals with a unilateral amputation.

OBJECTIVE: To explore relationships between balance-confidence and: 1) community participation; 2) self-perceived mobility; and 3) performance-based physical function among individuals with a lower-limb amputation using a prosthetic. Design: Retrospective, cross-sectional study. Setting: Outpatient, multidisciplinary amputee clinic. Participants: Patients (n = 45) using a prosthesis, aged ≥ 18 years, with a unilateral transfemoral or transtibial amputation of ≥1 year, were included. Methods: Participants completed the following self-report measures: Activities-Specific Balance Confidence Scale (ABC); Community Integration Questionnaire (CIQ); Locomotor Capabilities Index (LCI); and two performance-based measures (i.e. Timed Up and Go and 6 Minute Walk Test). Linear regression modeling was used to explore relationships between balance-confidence (i.e. ABC) and self-report (i.e. CIQ and LCI) and performance-based measures (p ≤ 0.0125). Results: After controlling for potential covariates (i.e. age, sex, and body mass index), balance-confidence explained 47.4% of the variance in CIQ (p = 0.000), 53.0% of the variance in LCI (p = 0.000), 20.3% of the variance in Timed Up and Go (p = 0.001), and 18.2% of the variance in 6 Minute Walk Test (p = 0.001). Conclusion: Lower balance-confidence is associated with less community participation, lower self-perceived mobility, and poorer performance among patients with a unilateral lower-limb amputation.

Exploring Neuromuscular Electrical Stimulation Intensity Effects on Multifidus Muscle Activity in Adults With Chronic Low Back Pain: An Ultrasound Imaging-Informed Investigation.

STUDY DESIGN: Cross-sectional study. BACKGROUND: Neuromuscular electrical stimulation (NMES) is an effective tool for stimulating multifidus muscle contractions. Ultrasound imaging (USI) is valid and reliable for quantifying multifidus activity represented by percent thickness change from a resting to contracted state. Thus, USI may be used to help determine optimal NMES intensity. OBJECTIVES: To explore NMES intensity effects on multifidus thickening in adults with chronic low back pain (CLBP). METHODS: Sixty patients with CLBP participated. L4/5 multifidus ultrasound images were obtained and percent thickness change from a resting to a contracted state was determined at baseline with a limb lift and during NMES application. During NMES, the examiner recorded the intensity, in milliampere, when the multifidus first started to thicken as observed with USI. The examiner also recorded the NMES intensity that resulted in no further multifidus thickening (ie, high-tolerance group) or, in cases where maximal thickening was not observed, the NMES intensity of the submaximal contraction (ie, low-tolerance group). Differences between participants with high versus low NMES tolerance were evaluated. RESULTS: During NMES, the multifidus began thickening at a higher intensity for the high-tolerance group (n = 39), that is, 34 mA, compared with the low-tolerance group (n = 21), that is, 32 mA (P = .001). A greater mean intensity in the high-tolerance group, that is, 62 mA, as compared to 45 mA in the low-tolerance group, resulted in a larger percent thickness change, that is, 30.89% compared to 20.60%, respectively (P < .001). CONCLUSIONS: Results provide clinicians with NMES intensity targets to facilitate multifidus muscle thickening, which provides insight into muscle activity.

Differences in Measures of Strength and Dynamic Balance Among Individuals With Lower-Limb Loss Classified as Functional Level K3 Versus K4.

OBJECTIVE: For individuals with lower-limb loss, functional mobility (ie, K-level) classification can be subjective. Performance-based outcome measures improve the objectivity of K-level assignment; therefore, this study aimed to determine differences in functional strength- and dynamic balance-based outcome measures performance between K3- and K4-classified adults with lower-limb loss. DESIGN: Prosthetists used subjective information and prosthetic componentry to determine K-levels before outcome measures testing for adults with a unilateral transtibial (n = 50) or transfemoral amputation (n = 17). Outcome measures (ie, 5-Times Sit-to-Stand Test, Figure-of-8 Walk Test, 360-degree Turn Test, and modified Four-Square Step Test) were administered by a blinded examiner. Univariate analyses of variance were used to evaluate between-subgroup differences. RESULTS: K4-classified participants with a unilateral transfemoral amputation performed better on all outcome measures when compared with K3-classified peers, whereas K4-classified individuals with a transtibial amputation performed better on the modified Four-Square Step Test compared with K3-classified peers (P < 0.050). CONCLUSIONS: K4-classified individuals demonstrated greater lower-limb functional strength and better dynamic balance compared with K3-classified peers. To assist with K-level classification, clinicians should consider selecting outcome measures that objectively differentiate between K-levels (ie, modified Four-Square Step Test for those with a unilateral transtibial or transfemoral amputation; 5-Times Sit-to-Stand Test, Figure-of-8 Walk Test, and 360-degree Turn Test for those with a transfemoral amputation).