A qualitative study of low-load resistance training with blood flow restriction in people with advanced multiple sclerosis.

BACKGROUND: Blood flow restriction (BFR) combined with low-load resistance training could minimize exercise barriers and offer strength and mobility improvements for people with advanced Multiple Sclerosis (MS); but patient experience has not been evaluated. PURPOSE: The purpose of this study was to assess the satisfaction, acceptability, and impact of combining low-load resistance training with BFR for individuals with advanced MS (Expanded Disability Status Scale: EDSS 6.0-7.0). METHODS: We used an interpretive phenomenological research design and post-intervention interviews to explore participant experiences of a novel low-load resistance training program with BFR. RESULTS: Interview participants (n = 14) were 55.4 ± 6.2 years old and were diagnosed with MS for 19.1 ± 10.7 years. Four themes were identified (satisfaction, acceptability, impact, program refinement) with 14 subthemes. Satisfaction was mixed based on overall expectations, yet all participants recommended the intervention. Acceptability was evidenced by all participants identifying comfortable/easy aspects, and modifiable elements that could improve comfort. Impact was evidenced with translation to everyday life activities, strength/self-efficacy/psychological improvements, effectiveness, and fatigue reduction. CONCLUSIONS: Participants found BFR combined with low-load resistance training to be satisfactory (mixed initial expectations), acceptable (comfortable/easy), and impactful (translating to life improvements). Areas for program refinement were identified that should be targeted in future iterations.

Blood Flow Restriction and Veterans with Multiple Sclerosis (BRaVe-MS) and Advanced Disability: Protocol for a Randomized Controlled Trial.

OBJECTIVE: The purpose of this study will be to determine the efficacy of low intensity lower extremity resistance training with and without blood flow restriction on quadriceps muscle strength and thickness in veterans with advanced multiple sclerosis (MS). METHODS: This will be an assessor-blinded, 2-group (1 to 1 allocation) randomized controlled trial targeting an enrollment of 58 participants with advanced MS as defined by Patient-Determined Disease Steps scale levels 4 to 7. Both groups will complete 10 weeks of twice weekly low-load resistance training (20% to 30% of 1-repetition max) targeting knee and hip extension, knee flexion, and ankle plantarflexion. The intervention group will perform all training using blood flow restriction, with limb occlusion pressures between 60% to 80% of maximal limb occlusion pressure. Primary outcomes will be quadriceps muscle strength and thickness. Secondary outcomes will include knee flexion and ankle plantarflexion strength, functional mobility, physical activity, and patient-reported measures. All outcomes will be assessed at baseline before the intervention, immediately after the intervention, and at a 2-month follow-up assessment. The change between groups post-intervention and after the 2-month follow-up will be reported for all outcomes. All analyses will assume a 2-sided test of hypothesis (α = .05). IMPACT: There is very little evidence for the efficacy of exercise interventions in people with MS who have advanced mobility disability. Resistance training with blood flow restriction may be an important approach for people with advanced MS who may not tolerate more conventional, moderate-to-high intensity resistance training. The results of this study will inform clinicians regarding exercise decisions for people with advanced MS and future investigations on the role of blood flow restriction in people with MS.

Development and alpha testing of a patient shared decision aid for prosthesis design for new lower limb prosthesis users.

BACKGROUND: After lower limb amputation, several prosthesis design options exist. However, prosthesis design decisions do not always reflect a prosthesis user's needs, values, and preferences. OBJECTIVE: To develop a patient decision aid (PDA) prototype for prosthetists and new prosthesis users facing prosthesis design decisions after lower limb amputation, and to assess its usability, accuracy, and comprehensibility. STUDY DESIGN: Exploratory mixed methods. METHODS: PDA development was informed by a qualitative needs assessment and guided by the International Patient Decision Aid Standards. The PDA was evaluated by steering groups of experienced prosthesis users and prosthetic professionals (prosthetists and researchers) to test usability, accuracy, and comprehensibility through focus groups, individual interviews, and rating on a Likert scale ranging from 1 to 10. RESULTS: The resulting PDA included 6 sections: (1) Amputation and Early Recovery, (2) Communication, (3) Values, (4) Prosthesis Design, (5) Preferences, and (6) Prosthetic Journey. Usability, accuracy, and comprehensibility were rated as 9.2, 9.6, and 9.6, respectively, by prosthetic professionals, and 9.4, 9.6, and 9.6, respectively, by prosthesis users. DISCUSSION: The PDA incorporated guidance by relevant stakeholders and was rated favorably, emphasizing a need for shared decision-making support in prosthesis design. One challenge was determining the amount of information in the PDA, highlighting the diversity in end users' informational needs. Future iterations of the PDA should undergo beta testing in clinical settings. CONCLUSIONS: A standardized, iterative method was used to develop a PDA for new lower limb prosthesis users and prosthetists when considering prosthesis design decisions. The PDA was considered useable, accurate, and comprehensible.

Feasibility of Low-Load Resistance Training Using Blood Flow Restriction for People With Advanced Multiple Sclerosis: A Prospective Cohort Study.

OBJECTIVE: The objective of this study was to determine the feasibility of low-load resistance training with blood flow restriction (BFR) for people with advanced disability due to multiple sclerosis (MS). METHODS: In this prospective cohort study, 14 participants with MS (Expanded Disability Status Scale [EDSS] score = 6.0 to 7.0; mean age = 55.4 [SD = 6.2] years; 71% women) were asked to perform 3 lower extremity resistance exercises (leg press, calf press, and hip abduction) bilaterally twice weekly for 8 weeks using BFR. Feasibility criteria were as follows: enrollment of 20 participants, ≥80% retention and adherence, ≥90% satisfaction, and no serious adverse events related to the intervention. Other outcomes included knee extensor, ankle plantar flexor, and hip abductor muscle strength, 30-Second Sit-to-Stand Test, Berg Balance Scale, Timed 25-Foot Walk Test, 12-Item MS Walking Scale, Modified Fatigue Impact Scale, Patient-Specific Functional Scale, and daily step count. RESULTS: Sixteen participants consented, and 14 completed the intervention, with 93% adherence overall. All participants were satisfied with the intervention. A minor hip muscle strain was the only intervention-related adverse event. There were muscle strength improvements on the more-involved (16%-28%) and less-involved (12%-19%) sides. There were also changes in the 30-Second Sit-to-Stand Test (1.9 repetitions; 95% CI = 1.0 to 2.8), Berg Balance Scale (5.3 points; 95% CI = 3.2 to 7.4), Timed 25-Foot Walk Test (-3.3 seconds; 95% CI = -7.9 to 1.3), Modified Fatigue Impact Scale (-8.8 points; 95% CI = -16.5 to -1.1), 12-Item MS Walking Scale (-3.6 points; 95% CI = -11.5 to 4.4), Patient-Specific Functional Scale (2.9 points; 95% CI = 1.9 to 3.8), and daily step count (333 steps; 95% CI = -191 to 857). CONCLUSION: Low-load resistance training using BFR in people with MS and EDSS scores of 6.0 to 7.0 appears feasible, and subsequent investigation into its efficacy is warranted. IMPACT: Although efficacy data are needed, combining BFR with low-load resistance training may be a viable alternative for people who have MS and who do not tolerate conventional moderate- to high-intensity training because of more severe symptoms, such as fatigue and weakness. LAY SUMMARY: Low-load strength training with BFR was feasible in people who have advanced disability due to MS. Using BFR may provide an alternative for people with MS who do not tolerate higher intensity training due to more severe symptoms, such as fatigue and weakness.

Self-assessed Dynamic Gait Index correlates with physical therapist assessed Dynamic Gait Index in people with multiple sclerosis.

BACKGROUND: The Dynamic Gait Index (DGI) is a clinical measure of walking ability comprised of eight walking tasks. In people with multiple sclerosis (PwMS) the DGI has demonstrated validity, reliability, and ability to identify fallers. A self-assessed version of the DGI that demonstrates concurrent validity with the original DGI in people with MS would be valuable for remote assessment of walking ability. We therefore developed a questionnaire-based self-assessed version of the DGI (sDGI) that asks participants to self-rate their predicted ability to perform the eight DGI walking tasks. The purpose of this study was to determine the validity and internal consistency of the sDGI in people with MS who had self-reported gait impairment. METHODS: We enrolled 53 ambulatory people with MS with self-reported gait impairment. Participants completed the sDGI, the Multiple Sclerosis Walking Scale-12 (MSWS-12), the Telephone Interview for Cognitive Status (TICS), and self-reported their number of falls in the past 3 months. Then, up to 4 weeks later, they completed the DGI by in-person evaluation by a physical therapist (PT). We calculated the internal consistency of the sDGI and concordance between the sDGI and DGI. To determine if cognition impacted concordance, we calculated concordance in the cognitively impaired and non-impaired groups and also tested the difference between groups. We also calculated correlation between the sDGI and the DGI and the MSWS-12. The ability of the sDGI and the DGI to identify fallers was evaluated using receiver operating characteristic curves. RESULTS: 51 participants completed the study. They had a mean age of 60.9 (SD 11.5) years, median PDDS of 4.0 (interquartile range 3, 5), 32 % used walking aids, 25 % were cognitively impaired, and 62 % were female. The sDGI was internally consistent (Cronbach's alpha 0.85, 95 % CI 0.76, 0.90) but was not concordant (CCC = 0.45, 95 % CI: 0.28-0.60) with the DGI. Concordance between the sDGI and DGI was not different for cognitively intact versus cognitively impaired individuals. The sDGI was moderately correlated with the DGI (R = 0.64, p < 0.01) and strongly correlated with the MSWS-12 (R = -0.71, p < 0.01). Neither the sDGI nor the DGI identified fallers in this sample. CONCLUSION: The moderate to strong correlation among the sDGI, DGI and MSWS-12 supports the validity of the sDGI as a measure of walking ability in people with MS. However, because there is poor concordance between the sDGI and the DGI performed in clinic by a PT in both cognitively intact and cognitively impaired participants, the sDGI should not be used as a substitute for the DGI. The sDGI could be used as a screening tool because most participants underestimated their walking performance compared to assessment by a PT so the sDGI would be unlikely to miss poor walking ability. As neither the sDGI nor the DGI identified fallers in this sample, our results do not support using these tools to identify fallers in people with MS and self-reported gait impairment.

Ultrasound measures of muscle morphology in people with multiple sclerosis are associated with muscle performance and functional mobility.

BACKGROUND: Neurologically-based muscle weakness is a common symptom in people with multiple sclerosis MS (MS), who may also exhibit muscle morphology changes and intrinsic muscle dysfunction. Diagnostic ultrasound (sonography) is a non-invasive, inexpensive, and clinically feasible method to measure muscle morphology. The purpose of this study was to investigate possible asymmetries in lower limb muscle morphology and performance in people with MS, and to assess the relationships of muscle morphology measures with individual patient characteristics, muscle performance, and functional mobility. METHODS: This cross-sectional study was conducted at the Washington, DC Veterans Affairs Medical Center. The study participants were 29 Veterans with MS (52% female, 79% African-American, 48.6 ± 11.2 years old, Mean Expanded Disability Status Scale: 3.6 ± 1.4) who completed seated knee extension isokinetic strength and power tests, functional assessments (Timed 25-Foot Walk - T25FW, 5-Times Sit-to-Stand - 5STS), and quantitative B-mode ultrasound image acquisition of the rectus femoris muscle to derive morphology measures (thickness and echogenicity). The limb with weaker knee extension strength was identified as the more-involved limb. Differences between the more and less-involved limb were quantified using a t-test for all muscle morphology and muscle performance measures. Relationships between muscle morphology and patient characteristics, muscle performance, and functional mobility were evaluated using bivariate and multivariate analyses. RESULTS: The rectus femoris thickness from the more-involved limb was lower (p<0.001) than that of the less-involved limb, whereas echogenicity was not different between the two limbs (p=0.147). Rectus femoris thickness of the more-involved limb was directly related to age (r=-0.63, p<0.001), muscle strength (r=0.53, p=0.003) and power (r=0.53, p=0.003), and gait speed (r=0.42, p=0.024); whereas its echogenicity was positively associated only with muscle strength (r=-0.46, p=0.013) and power (r=-0.50, p=0.006). Together rectus femoris thickness and echogenicity of the more involved limb explained 44% and 48% of the variance in muscle strength and power, respectively (p<0.001). CONCLUSION: This study supports the ability of sonography to measure muscle morphology in people with MS, identify asymmetries, and quantify associations with important clinical correlates. Compared with more invasive and costly alternatives, sonography is a clinically feasible, relatively low-cost tool that can be used to assess muscle morphology in people with MS. Further research is warranted to determine the potential clinical utility of sonographic measures of muscle morphology in evaluating changes due to disease progression or therapeutic interventions in this population.

Reliability, Validity, and Responsiveness of the Patient-Specific Functional Scale for Measuring Mobility-Related Goals in People With Multiple Sclerosis.

BACKGROUND AND PURPOSE: This study's purpose was to investigate the reliability, validity, and responsiveness of the Patient-Specific Functional Scale (PSFS) for measuring mobility-related goals in people with multiple sclerosis (MS). METHODS: Data from 32 participants with MS who underwent 8 to 10 weeks of rehabilitation were analyzed (Expanded Disability Status Scale scores 1.0-7.0). For the PSFS, participants identified 3 mobility-related areas where they had difficulty and rated them at baseline, 10 to 14 days later (before starting intervention), and immediately after intervention. Test-retest reliability and response stability of the PSFS were calculated using the intraclass correlation coefficient (ICC 2,1 ) and minimal detectable change (MDC 95 ), respectively. Concurrent validity of the PSFS was determined with the 12-item Multiple Sclerosis Walking Scale (MSWS-12) and the Timed 25-Foot Walk Test (T25FW). PSFS responsiveness was determined using Cohen's d , and minimal clinically important difference (MCID) was calculated based on patient-reported improvements on a Global Rating of Change (GRoC) scale. RESULTS: The PSFS total score demonstrated moderate reliability (ICC 2,1 = 0.70, 95% CI: 0.46 to 0.84) and the MDC was 2.1 points. At baseline, the PSFS was fairly and significantly correlated with the MSWS-12 ( r = -0.46, P = 0.008) but not with the T25FW. Changes in the PSFS were moderately and significantly correlated with the GRoC scale (ρ = 0.63, P < 0.001), but not with MSWS-12 or T25FW changes. The PSFS was responsive ( d = 1.7), and the MCID was 2.5 points or more to identify patient-perceived improvements based on the GRoC scale (sensitivity = 0.85, specificity = 0.76). DISCUSSION AND CONCLUSIONS: This study supports the use of the PSFS as an outcome measure in people with MS to assess mobility-related goals.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A423 ).

Improving shared decision-making for prosthetic care: A qualitative needs assessment of prosthetists and new lower-limb prosthesis users.

BACKGROUND: Prosthesis design is complex and multiple appropriate options exist for any individual with lower-limb amputation. However, there is insufficient evidence for guiding decision-making. Shared decision-making (SDM) offers an opportunity to incorporate patient-specific values and preferences where evidence is lacking for prosthesis design decisions. To develop resources to facilitate SDM, and consistent with the International Patient Decision Aid Standards, it is necessary to identify the decisional needs of prosthetists and prosthesis users for prosthesis design decisions. OBJECTIVES: To assess the needs of prosthetists and new prosthesis users for SDM about the first prosthesis design. STUDY DESIGN: Qualitative descriptive design. METHODS: Six focus groups were conducted with 38 prosthetists. Individual semistructured interviews were conducted with 17 new prosthesis users. Transcripts were analyzed using directed content analysis, with codes defined a priori using existing frameworks for SDM: the Three Talk Model for SDM and the Ottawa Decision Support Framework. RESULTS: Four main themes were identified among prosthetists and prosthesis users: acknowledging complexity in communication, clarifying values, recognizing the role of experience to inform preferences , and understanding the prosthetic journey . CONCLUSIONS: Resources that support SDM for the first prosthesis design should consider methods for identifying individual communication needs, support with clarifying values, and resources such as experience for achieving informed preferences, within the context of the overall course of rehabilitation and recovery following lower-limb amputation. The themes identified in this work can inform SDM to promote collaborative discussion between prosthetists and new prosthesis users when making prosthesis design decisions.

Clinical utility of the Trendelenburg Test in people with multiple sclerosis.

BACKGROUND: The clinical utility of the Trendelenburg Test remains unknown in people with multiple sclerosis (MS). OBJECTIVE: To measure (1) intra-rater reliability, (2) agreement of goniometer-assessed Trendelenburg pelvis-on-femur angle (POF) with motion capture, and (3) concurrent validity of Trendelenburg POF and hip abduction strength with POF during walking and step negotiation. METHODS: Trendelenburg POF was measured in 20 people with MS using goniometry and motion analysis. In addition, peak POF was measured using motion analysis during walking, step ascent, and step descent. Intra-rater reliability of goniometer-assessed Trendelenburg POF and agreement with motion analysis-assessed POF were analyzed. Pearson's r was used to determine the relationships between Trendelenburg POF and hip abduction strength with peak POF during each functional activity. RESULTS: Goniometer-assessed Trendelenburg POF demonstrated very strong reliability (ICC: 0.948), strong agreement with 3D motion analysis (ICC: 0.792), correlated moderately with peak POF during walking (r = 0.519) and step ascent (r = 0.572), and weakly with step descent (r = 0.463). Hip abductor strength correlated weakly with peak POF during step ascent (r = -0.307) and negligibly during walking (r = -0.270) and step descent (r = -0.249). CONCLUSIONS: Goniometer-assessed Trendelenburg POF was reliable, agreed with motion analysis, and may provide insight into hip abduction muscle performance during functional activities in people with MS.

Clinical use of blood flow restriction in people with neurologic conditions: a cross-sectional survey.

[Purpose] There is little evidence for blood flow restriction (BFR), or Kaatsu, training in people with neurologic conditions. This study's purpose was to survey clinicians on BFR use in people with neurologic conditions. [Participants and Methods] One-hundred twelve physical therapists and other healthcare professionals who reported using BFR in the past 5 years completed an anonymous, online survey. [Results] Eighty-nine percent of respondents thought BFR was safe in people with neurologic conditions. Meanwhile, 38% reported BFR use in people with neurologic conditions. The most common intervention used with BFR was resistance training (n=33) and the most commonly reported benefit was improved strength (n=27). The most common side-effect causing treatment to stop was intolerance to pressure (n=6). No side-effects requiring medical attention were reported. In order to support future BFR use in neurologic populations, the most common response was the need for more research (n=63). [Conclusion] Despite the lack of evidence, clinical use of BFR in people with neurologic conditions may be somewhat common. Although this study had a relatively small sample size and collected data retrospectively, the results support the potential clinical feasibility and safety of BFR use in patients with neurologic conditions and suggest that more research is needed.

The Impact of COVID-19 on Community-Based Exercise Classes for People With Parkinson Disease.

OBJECTIVE: he purpose of the study was to determine the impact of novel coronavirus 2019 (COVID-19) restrictions on community-based exercise classes for people with Parkinson disease (PD) and their instructors. METHODS: Data were collected via custom-designed electronic surveys for people with PD and class instructors who reported attending or teaching PD-specific exercise class ≥1 time/week for ≥3 months prior to pandemic restrictions (March 2020). The PD group also completed the Godin Leisure-Time Questionnaire, Self-Efficacy for Exercise scale, Schwab-England scale, and Parkinson's Disease Questionnaire 8. RESULTS: Eighty-seven people with PD (mean = 70 [7.3] years old) and 43 instructors (51 [12.1] years old) from the United States completed surveys (October 2020 to February 2021). Mean Schwab-England (84 [16]) and Parkinson's Disease Questionnaire 8 (21 [15]) scores indicated low-to-moderate disability in the PD group. Ninety-five percent of the PD group had COVID-19 exposure concerns, and 54% reported leaving home ≤1 time/week. Although 77% of the PD group scored "active" on the Godin Leisure-Time Questionnaire, the mean Self-Efficacy for Exercise Scale score (55 [24]) indicated only moderate exercise self-efficacy, and >50% reported decreased exercise quantity/intensity compared with pre-COVID. There was decreased in-person and increased virtual class participation for both groups. The top in-person class barrier for the PD (63%) and instructor (51%) groups was fear of participant COVID-19 exposure. The top virtual class barriers were lack of socialization (20% of PD group) and technology problems (74% of instructor group). CONCLUSION: During COVID-19, there has been less in-person and more virtual exercise class participation in people with PD and decreased exercise quantity and intensity. Virtual classes may not fully meet the needs of people with PD, and primary barriers include technology and lack of socialization. IMPACT: As COVID-19 restrictions wane, it is imperative to help people with PD increase exercise and activity. The barriers, needs, and facilitators identified in this study might help inform approaches to increase participation in exercise and activity for people with PD. LAY SUMMARY: During COVID-19, there has been less in-person and more virtual exercise class participation in people with PD and a decrease in exercise quantity and intensity. If you have PD, virtual classes might not fully meet your needs. Primary barriers may include technology problems and lack of social interaction.

The Validity of the Single-Leg Heel Raise Test in People With Multiple Sclerosis: A Cross-Sectional Study.

Background: The single-leg heel raise test is a common clinical assessment; however, little is known about its validity in people with multiple sclerosis (MS). This study investigated the validity of the single-leg heel raise test in a group of people with MS and a healthy control group (CTL). Materials and Methods: Twenty-one people with MS (49 ± 12 years, Expanded Disability Status Scale 1.5-5.5) and 10 healthy controls (48 ± 12 years) performed the single-leg heel raise test, ankle plantarflexion isometric strength assessment using electromechanical dynamometry, and mobility measures (Timed 25-Foot Walk, 2-Min Walk Test, Functional Stair Test). Results: Convergent validity between the heel raise test and strength was moderate for participants with MS completing <20 heel raises (r = 0.63, p = 0.001) but weak for the entire sample (r = 0.30, p = 0.020). Compared to the average CTL group values, the heel raise test differentiated between groups on the MS groups' weaker (p < 0.001) and stronger (p = 0.003) limbs, while strength only differentiated between groups on the weaker limb (p = 0.010). Considering the weaker and strong limbs from the MS group and the CTL group average values, the mobility measures had moderate-to-strong correlations with the heel raise test on the weaker MS limb + CTL (r = 0.71-0.78) and stronger MS limb + CTL (r = 0.62-0.70), and weak-to-moderate correlations with strength on the weaker MS limb + CTL (r = 0.49-0.58, p = 0.001-0.007). Discussion: In people with MS, the single-leg heel raise test may be clinically useful as it identified impaired muscle performance and differentiated muscle performance from a healthy control group and, together with the control group, correlated with functional mobility.

Movement compensations during a step ascent task are associated with stair climbing performance in people with multiple sclerosis.

BACKGROUND: The biomechanical mechanisms underlying stair climbing limitations are poorly understood in people with multiple sclerosis (MS). RESEARCH QUESTIONS: Are trunk and pelvis motion and lower extremity joint moments during step ascent different between MS and control groups? Are step ascent biomechanics and stair climbing performance associated in people with MS? METHODS: 20 people with MS (49 ±â€¯12 years, EDSS range: 1.5-5.5) and ten control participants (48 ±â€¯12 years) underwent three-dimensional motion analysis while ascending a 15.2-cm step and also completed a timed Functional Stair Test. Main effects of group (MS vs Control) and limb (Stronger/Dominant vs Weaker/Non-dominant) and interactions were assessed using two-way analyses of variance. Associations between movement patterns during the step ascent and Functional Stair Test performance were performed using Pearson's correlations and backward stepwise linear regression. RESULTS: Significant group main effects were observed in greater sagittal pelvis excursion (p < 0.001), greater sagittal (p = 0.013) and frontal (p = 0.001) trunk excursion, and lower trail limb peak ankle plantar flexion moment (p < 0.001) of the MS group. Significant limb main effects were observed with greater sagittal trunk excursion (p = 0.037) and peak trail limb ankle plantar flexion moment (p = 0.037) in the stronger/dominant limb. A significant interaction was observed in peak knee extensor moment (p = .002). Stair climbing performance in the MS group correlated with sagittal (r = .607, p=<0.001) and frontal pelvis excursions (r = 0.385, p = 0.014), sagittal trunk excursion (r = .411, p = 0.008), and ankle plantar flexion moments (r=-0.415, p = 0.008). Sagittal and frontal pelvis excursion and bilateral handrail use explained a significant amount of variability in stair climbing performance (Adj R2 = 0.775). SIGNIFICANCE: In conclusion, despite the presence of proximal and distal lower extremity movement pattern compensations during a step ascent task, larger pelvis angular excursions are associated with impaired stair climbing performance in people with MS and may serve as targets for future rehabilitation interventions.

The "Journal of Functional Morphology and Kinesiology" Journal Club Series: PhysioMechanics of Human Locomotion.

We are glad to introduce the Third Journal Club of Volume five, the third issue. This edition is focused on relevant studies published in the last years in the field of PhysioMechanics of Human Locomotion, chosen by our Editorial Board members and their colleagues. We hope to stimulate your curiosity in this field and to share with you the passion for the Sports Medicine and Movement Sciences seen also from the scientific point of view. The Editorial Board members wish you an inspiring lecture.

Does disability level impact the relationship of muscle strength to walking performance in people with multiple sclerosis? a cross-sectional analysis.

BACKGROUND AND PURPOSE: Strength training can improve muscle weakness in people with multiple sclerosis (MS), but does not consistently improve walking. Disability level may impact the relationship of muscle weakness and walking performance in people with MS, but few studies have investigated the impact of disability on the relationship of strength and walking. The purpose of this study was to compare the relationships of strength in lower body and trunk muscles to walking performance between mild and moderate disability groups in people with MS. METHODS: Data from 36 participants with MS who had mild disability (Expanded Disability Status Scale - EDSS 0 to 3.5) and 36 participants who had moderate disability (EDSS 4.0 to 5.5) were analyzed. Hand-held dynamometry measured strength in eight muscle groups from the ankle, knee, hip, and trunk. Timed 25-Foot Walk (T25FW) and 6-Minute Walk Test (6MWT) measured walking speed and endurance, respectively. Pearson correlations and beta coefficients (ß) were reported for each bivariate relationship of muscle strength to T25FW and 6MWT from both mild and moderate disability groups. Linear regression was then used to compare differences in beta coefficients (Δß) between disability groups for the relationship of each muscle variable to T25FW and 6MWT. A positive Δß indicated a stronger relationship of strength to walking performance in the mild disability group, while a negative Δß favored the moderate disability group. RESULTS: Overall, there were stronger Pearson correlations between muscle strength variables to T25FW and 6MWT in the mild (r = 0.57 to 0.77) compared to moderate disability group (r = 0.10 to 0.54). The mild disability group had significantly greater beta coefficients for T25FW with ankle dorsiflexion (Δß = 0.67, 95%CI: 0.27-1.07), knee extension (Δß = 0.68, 95%CI: 0.28-1.08), and hip abduction (Δß = 0.77, 95%CI: 0.01-1.52); and for 6MWT with knee extension (Δß = 0.47, 95%CI: 0.06 to 0.88). DISCUSSION AND CONCLUSION: For people with MS, muscle strength in the lower extremity and trunk may be a more important contributor to T25FW in mild versus moderate disability, but not for 6MWT. While more studies are needed, these results may help to inform rehabilitation intervention when prioritizing strength training to improve walking.

Association of the Dynamic Gait Index to fall history and muscle function in people with multiple sclerosis.

Background and purpose: This study examined the association of a commonly used gait assessment, the Dynamic Gait Index, with falls and lower extremity and trunk muscle function in people with multiple sclerosis.Materials and methods: Cross-sectional data from 72 people with multiple sclerosis (Expanded Disability Status Scale 3.5 ± 1.14) were used. The ability of the Dynamic Gait Index to identify fallers was evaluated using the receiver operating characteristic curve. Multiple linear regression determined contributions of muscle function variables to Dynamic Gait Index scores.Results: Thirty-seven participants reported at least one fall in the previous 3 months (51%). The area under the curve for the Dynamic Gait Index was 0.80 (95% CI: 0.69-0.90), indicating a good ability to identify fallers with a cutoff of ≤19/24. After adjusting for age, sex, and disability level, a one standard deviation increase in ankle plantarflexion (15.2 repetitions) and trunk flexion (15.1 repetitions) endurance were associated with an increase in Dynamic Gait Index score of 0.73 (95% CI: 0.07-1.39) and 0.62 (95% CI: 0.002-1.25), respectively.Conclusions: The Dynamic Gait Index may be a useful tool to identify fallers, and was associated with ankle plantarflexion and trunk flexion endurance.Implications for rehabilitationThe Dynamic Gait Index appears to be a useful tool to identify people with multiple sclerosis at increased risk for falls using a cutoff score of ≤19/24.The ability to do fewer than 13 single leg heel raises had a moderate ability to identify fallers in this study.Out of 11 lower extremity and trunk muscles, only ankle plantarflexion and trunk flexion muscle endurance were significant predictors of Dynamic Gait Index scores.Clinicians may consider targeting ankle plantarflexion and trunk muscle endurance to improve dynamic gait and fall risk in patients with multiple sclerosis.

Strength Training to Improve Gait in People with Multiple Sclerosis: A Critical Review of Exercise Parameters and Intervention Approaches.

BACKGROUND: There are mixed reports on the effectiveness of strength training to improve gait performance in people with multiple sclerosis (MS), yet the reasons for these inconsistent results are not clear. Therefore, a critical review was conducted to explore dosage, frequency, mode, position, and muscle targets of studies that have included strength training in people with MS. METHODS: An electronic search was conducted through July 2017. Randomized controlled trials involving people with MS were included that implemented strength training with or without other interventions and assessed 1) strength in the lower extremities and/or trunk and 2) gait speed and/or endurance. Strength and gait results were extracted, along with exercise frequency, intensity, duration, mode, position, and muscle targets. RESULTS: Thirteen trials met the inclusion criteria; nine used dosing consistent with recommended guidelines. Overall, six studies reported significant between-group strength improvements, and four reported within-group changes. Four studies reported significant between-group gait improvements for gait speed and/or endurance, and two reported within-group changes. Most exercises were performed on exercise machines while sitting, supine, or prone. The most common intervention target was knee extension. CONCLUSIONS: Studies generally improved strength, yet only two studies reported potentially meaningful between-group changes in gait. Future strength intervention studies designed to improve gait might consider dosing beyond that of the minimum intensity to improve strength and explore muscles targets, positions, and modes that are task-specific to walking.

Feasibility of a targeted strengthening program to improve gait in people with multiple sclerosis: a brief report.

This study aims to determine feasibility of strengthening muscles that are important contributors to gait for people with multiple sclerosis, yet are not routinely targeted in the literature. An 8-week strengthening intervention targeted ankle plantarflexion, hip abduction, and trunk muscles using a repeated-measures design. Outcomes included satisfaction, adherence, muscle strength, gait speed (timed 25-foot walk), gait endurance (6-min walk test), and self-reported gait-related participation (Multiple Sclerosis Walking Scale-12). Ten participants (Expanded Disability Status Scale: 3.5-5.5) completed the intervention. All participants were at least 'satisfied'; adherence was 87% (supervised sessions) and 75% (home sessions). All quantitative measures improved: muscle strength (23.1-47.6%, P<0.001-0.039), timed 25-foot walk (-13.4%, P<0.001), 6-min walk test (41.56 m, P=0.019), and Multiple Sclerosis Walking Scale-12 (-10.5, P=0.007). Strengthening of ankle plantarflexion, hip abduction, and trunk muscles was feasible and associated with improvements in gait performance.

Contributions of Ankle, Knee, Hip, and Trunk Muscle Function to Gait Performance in People With Multiple Sclerosis: A Cross-Sectional Analysis.

Background: The relative importance of lower extremity and trunk muscle function to gait in people with multiple sclerosis (MS) is unknown. Objective: This study aimed to investigate the association of lower extremity and trunk muscle function with gait performance in people who have MS and mild-to-moderate disability. Design: This was a cross-sectional, observational study. Methods: Participants were people who had an Expanded Disability Status Scale score of ≤ 5.5. Eleven lower extremity and trunk muscles were assessed using handheld dynamometry or endurance tests. Gait performance was assessed with the Timed 25-Foot (7.62 m) Walk (T25FW) and 6-Minute Walk Test (6MWT). Regression analysis was used to quantify the association between gait outcomes and muscle variables. Results: Seventy-two participants with MS and a mean Expanded Disability Status Scale score of 3.5 (SD = 1.14) were enrolled. Adjusted for age and sex, the multivariate model including hip abduction, ankle plantar flexion, trunk flexion, and knee flexion explained 57% of the adjusted variance in the T25FW; hip abduction, ankle plantar flexion, and trunk flexion explained 61% of the adjusted variance in the 6MWT. The strongest predictors were ankle plantar flexion endurance for the T25FW and hip abduction strength for the 6MWT: a 1-SD increase in ankle plantar flexion (15.2 heel-raise repetitions) was associated with a 0.33-second reduction in the T25WT (95% CI = - 0.71 to - 0.14 seconds); a 1-SD increase in normalized hip abduction strength (0.14 kg/body mass index) was associated with a 54.4-m increase in the 6MWT (28.99 to 79.81 m). Limitations: Different measurement scales for independent variables were included because the muscle function assessment used either force or endurance. Conclusions: For the major muscles in the lower extremity and trunk, hip abduction, ankle plantar flexion, trunk flexion, and knee flexion were the strongest predictors of gait performance.

Psychometric Properties of a Clinical Strength Assessment Protocol in People with Multiple Sclerosis.

BACKGROUND: Strength training in people with multiple sclerosis (MS) is an important component of rehabilitation, but it can be challenging for clinicians to quantify strength accurately and reliably. This study investigated the psychometric properties of a clinical strength assessment protocol using handheld dynamometry and other objective, quantifiable tests for the lower extremities and trunk in people with MS. METHODS: This study determined discriminant validity between 25 participants with MS and 25 controls and between participants with MS who had higher versus lower disability; test-retest reliability across 7 to 10 days; and response stability. The protocol included handheld dynamometry measurements of ankle dorsiflexion, knee flexion and extension; hip flexion, extension, abduction, and adduction; and trunk lateral flexion. Muscular endurance tests were used to measure trunk extension, trunk flexion, and ankle plantarflexion. RESULTS: The protocol discriminated between participants with MS and controls for all muscles tested (P < .001-.003). The protocol also discriminated between low- and moderate-disability groups (P = .001-.046) for 80% of the muscles tested. Test-retest reliability intraclass correlation coefficients were high (0.81-0.97). Minimal detectable change as a percentage of the mean was 13% to 36% for 85% of muscles tested. CONCLUSIONS: This study provides evidence for the discriminant validity, test-retest reliability, and response stability of a strength assessment protocol in people with MS. This protocol may be useful for tracking outcomes in people with MS for clinical investigations and practice.