Stair-climbing Research Articles

Impact Of Resistance Training On Skeletal Muscle Mass And Physical Function In Older Adults

Aging is often accompanied with the onset of sarcopenia, defined by low muscle mass, strength, and physical function. Regular resistance exercise may mitigate this loss; however, data are lacking that compare young and old adults who do and do not perform resistance training for general health on skeletal muscle mass and physical function. PURPOSE: The aim of this study was to identify differences in muscle mass and physical function between young and old adults who did and did not perform resistance training for general health. METHODS: Healthy younger (23.8 ± 0.6 yrs) and older (68.6 ± 1.7 yrs) men and women (n = 67) who either did or did not regularly participate in resistance training were assigned to 1 of 4 groups: young trained (YT: n = 22); young not trained (YNT: n = 15); old trained (OT: n = 11); and old not trained (ONT: n = 19). Dual energy x-ray absorptiometry assessed appendicular skeletal muscle mass (SMI). Participants performed 4 physical function tests: stair climb (SC), 30s sit-to-stand (30sSTS), 6-min walk test (6MWT), and timed-up-and-go (TUG). ANOVAs were used to compare groups for all measures, p ≤ 0.05. Data are reported as mean ± SE. RESULTS: We found differences between groups for SMI, SC, 30sSTS, 6MWT, and TUG (p ≤ 0.05). SMI was higher for YT compared to YNT (p = 0.003) and ONT (p > 0.003; YT: 8.60 ± 0.37 kg/m2, YNT: 6.88 ± 0.17 kg/m2, OT: 7.69 ± 0.42 kg/m2, ONT: 7.04 ± 0.29 kg/m2). SC performance was faster for YT (p < 0.0001), YNT (p < 0.0001) and OT (p = 0.03) compared to ONT (YT: 2.37 ± 0.05 s, YNT: 2.52 ± 0.08 s, OT: 2.81 ± 0.12 s, ONT: 3.33 ± 0.17 s). For 30sSTS, OT completed more reps than ONT (p < 0.0001) and YT completed more reps than YNT (p = 0.001) and ONT (p < 0.0001; YT: 22.8 ± 0.5 reps, YNT: 18.9 ± 0.7 reps, OT: 21.6 ± 1.3 reps, ONT: 16.7 ± 0.6 reps). For 6MWT, OT walked farther than ONT (p = 0.017) and YT walked farther than ONT (p = 0.001; YT: 837.0 ± 16.7 yds, YNT: 785.5 ± 15.1 yds, OT: 829.2 ± 31.9 yds, ONT: 733.6 ± 20.4 yds). For TUG, OT was faster than ONT (p = 0.006; YT: 5.81 ± 0.17 s, YNT: 5.88 ± 0.26 s, OT: 5.21 ± 0.23 s, ONT: 6.38 ± 0.23 s). SMI, SC, 30sSTS, 6MWT and TUG were not different between OT and YT or YNT (p > 0.05). All other comparisons were not significantly different (p > 0.05). CONCLUSION: These data suggest that older adults who engage in regular resistance training may maintain muscle mass and physical function similar to that of younger adults.

Wearable-Based Stair Climb Power Estimation and Activity Classification.

Stair climb power (SCP) is a clinical measure of leg muscular function assessed in-clinic via the Stair Climb Power Test (SCPT). This method is subject to human error and cannot provide continuous remote monitoring. Continuous monitoring using wearable sensors may provide a more comprehensive assessment of lower-limb muscular function. In this work, we propose an algorithm to classify stair climbing periods and estimate SCP from a lower-back worn accelerometer, which strongly agrees with the clinical standard (r = 0.92, p < 0.001; ICC = 0.90, [0.82, 0.94]). Data were collected in-lab from healthy adults (n = 65) performing the four-step SCPT and a walking assessment while instrumented (accelerometer + gyroscope), which allowed us to investigate tradeoffs between sensor modalities. Using two classifiers, we were able to identify periods of stair ascent with >89% accuracy [sensitivity = >0.89, specificity = >0.90] using two ensemble machine learning algorithms, trained on accelerometer signal features. Minimal changes in model performances were observed using the gyroscope alone (±0–6% accuracy) versus the accelerometer model. While we observed a slight increase in accuracy when combining gyroscope and accelerometer (about +3–6% accuracy), this is tolerable to preserve battery life in the at-home environment. This work is impactful as it shows potential for an accelerometer-based at-home assessment of SCP.

The Impact Of Leg Asymmetry On Stair Climb Performance In Career Firefighters

Limb-specific regional tissue distribution can be determined using segmental body composition analyses to indicate between limb asymmetries. It is unclear how leg muscle imbalance, as measured by fat free mass, may contribute to performance on job-related tasks. PURPOSE: The purpose of this study was to examine the relationship between leg fat free mass asymmetry (FFMA) and stair climb performance (SCP) in career firefighters. METHODS: Forty-one firefighters [age: 32.3±8.2 years (20-50); stature: 178.3±7.9 cm (159.2-194.6); mass: 92.3±18.7 kg (65.1-133.2); %BF: 24.1±7.9% (9.9-39.4)] volunteered for this investigation. All participants were free of any neuromuscular, cardiovascular, or metabolic diseases, and were instructed to refrain from caffeine and smokeless tobacco for 12 hours, and vigorous lower body exercise for 48 hours. Following an 8 hour fast, %BF and leg FFM was assessed by a daily calibrated dual-energy x-ray absorptiometry. Participants were fitted with a weighted vest (22.73 kg) to simulate the load of their personal protective equipment and self-contained breathing apparatus. Performance was measured as time to completion (s) of stair assent and decent of 26 stairs (20 cm stair height) four times as fast as possible (104 total stairs). Leg FFMA was defined as ±3% difference between leg fat free mass as a cutoff point. A point biserial correlation between FFMA and SCP was performed. In addition, the relationship between FFMA and SCP, while controlling for age and %BF, was assessed. An alpha level was set a priori at 0.05. RESULTS: The point biserial correlation demonstrated that FFMA was significantly associated with SCP (r=0.519, P<0.001). Due to the large range in age and %BF, a follow-up partial correlation analysis controlling for these variables was performed and indicated a similar relationship between FFMA and SCP (r = 0.561, P<0.001). CONCLUSIONS: These findings suggest that the presence of leg FFMA is related to poorer performance on the stair climb assessment with and without accounting for age and %BF. While age is non-modifiable, maintaining good body composition (i.e., %BF and muscle symmetry) as a firefighter may help preserve performance on fire-related tasks. Strategies to improve body composition may impact SCP in firefighters.

Comparative Effects of Motor and Cognitive Dual- Task Gait Training on balance and mobility in persons with Intellectual Disabilities

Background: Dual tasks fall into two main groups: motor dual tasks, which require performance of a motor task and a postural control task at the same time; and cognition dual task that require performance of a cognition task and postural control task at the same time. Aim: To focus on comparative effects of motor and cognitive dual-task gait training on balance and mobility in persons with intellectual disabilities Methodology: A randomized clinical trial was conducted on 52 subjects (n=26) in a District Headquarter Hospital, Mirpur AJK. Fifty-two patients were randomly allocated in two groups as Group A received motor dual task and Group B received cognitive dual task training. Total duration of study was three weeks and assessment done before treatment and after every week. Rancho Los Amigos Cognitive Functional Scale (RLACF), Berg Balance Scale (BBS), Walking While Talking Test (WWT) and Stair Climb Test (SCT) for the assessment of the patient’s improvement in skills, balance and mobility. Results: The results of the study concluded that Rancho Los Amigos Cognitive Function Scale, Berg Balance Scale, Walking While Talking Test and Stair Climb Test scores were improved in both groups significantly. But on comparison; Cognitive dual task training significantly produce better results in improving the balance and mobility in the person with intellectual disability as compared to Motor dual task training with p value&lt;0.005. Conclusion: The study concluded that Cognitive dual task training is statistically and clinically more significant in improving the balance and mobility in the intellectual disable persons as compared to Motor dual task training. Key words: Cognitive dual task, Intellectual disabilities, Motor and cognitive dual-task gait training.

Modeling the Transitional Kinematics Between Variable-Incline Walking and Stair Climbing.

Although emerging powered prostheses can enable people with lower-limb amputation to walk and climb stairs over different task conditions (e.g., speeds and inclines), the control architecture typically uses a finite-state machine to switch between activity-specific controllers. Because these controllers focus on steady-state locomotion, powered prostheses abruptly switch between controllers during gait transitions rather than continuously adjusting leg biomechanics in synchrony with the users. This paper introduces a new framework for powered prosthesis control by modeling the lower-limb joint kinematics over a continuum of variable-incline walking and stair climbing, including steady-state and transitional gaits. Steady-state models for walking and stair climbing represent joint kinematics as continuous functions of gait phase, forward speed, and incline. Transition models interpolate kinematics as convex combinations of the two steady-state models, with an additional term to account for kinematics that fall outside their convex hull. The coefficients of this convex combination denote the similarity of the transitional kinematics to each steady-state mode, providing insight into how able-bodied individuals continuously transition between ambulation modes. Cross-validation demonstrates that the model predictions of untrained kinematics have errors within the range of physiological variability for all joints. Simulation results demonstrate the model's robustness to incline estimation and mode classification errors.

Design and Study of a Stair Climbing Robots with Two Wheels and a “4R+2P” Pattern

Aimed at the current major problems of “slipping, misstep and misplace” in the robot stair climbing process and at reaching the goals of being “flexible, adaptive and stable” in multiple scenarios, a two-wheeled robot with a “4R+2P” pattern that can independently climb different structures of stairs is proposed, and a gait pattern for stair climbing through a four-step cycle of “approaching, lifting, putting and retraction” based on this pattern is proposed. Relevant kinematic and dynamic models are established to study the constraint relation. In the experiment, the robot goes up and down different stairs. The simulation and experimental results showed that the two-wheeled robot with a “4R+2P” configuration fundamentally realized up–down stair climbing, adaptive steering and multiscene functions.

Poster 244: Pain Catastrophizing in Patellar Instability Patients Undergoing MPFL Reconstruction

Objectives:Pain catastrophizing was established as a way to measure patient perception and response to pain, as represented by three subscores: rumination, magnification, and helplessness. Prior clinical studies have demonstrated the close relationship between pain catastrophizing and persistent postoperative pain after total knee arthroplasty. Among patellofemoral instability patients, pain catastrophizing has also been investigated. However, specific patient factors that contribute to greater degrees of pain catastrophizing in patellofemoral instability are not yet understood. Additionally, investigations of the association between preoperative catastrophizing and postoperative pain are limited. Therefore, the purpose of this study is to investigate risk factors for higher preoperative pain catastrophizing and its correlation with pain scores following medial patellofemoral ligament reconstruction (MPFLR).Methods:This study retrospectively evaluated patients who underwent MPFLR between 2015 and 2020 with preoperative pain catastrophizing scores (PCS). Patient demographics were collected to evaluate risk factors for worse PCS scores. Four overlapping questions from the KOOS JR and full KOOS questionnaires were utilized at the preoperative and 6 months postoperative time points to assess pain on a scale from 0 (least) to 4 (most), including pain with: 1.) Knee Twisting, 2.) Knee Straightening, 3.) Stair Climbing, and 4.) Standing Upright.Results:Thirty-four patients were included for analysis. Higher age at the time of surgery was significantly associated with worse Helplessness (R2=0.11, p=.035), Rumination (R2=0.18, p=.020), and Total PCS scores (R2=0.08, p=.039). Patients with >5 instability events reported significantly worse Rumination (2.29±2.87 vs 4.60±3.31, p=.049). At 6 months post-operatively, 32.35% of patients (11/34) continued to report moderate pain in at least one pain category. These patients reported significantly greater Rumination at baseline (2.91 ± 3.37 vs 6.64 ± 5.22, p = .017). Lastly, higher baseline Helplessness significantly correlated with greater improvement in pain with stairs (p = .049), higher Magnification significantly correlated with greater improvement in pain with standing (p = .012), and higher baseline Total PCS correlated with more improvement in pain with stairs (p = .035) and standing (p = .037). Multivariate analysis demonstrated that history of prior surgery and age remained independently predictive of postoperative pain scores (Table 1).Conclusions:Older age and >5 instability events at presentation were patient risk factors associated with increased pain catastrophizing. Pain catastrophizing had different correlations with postoperative pain depending on subscore, with higher Rumination associated with persistent moderate pain while higher Magnification or Helplessness correlated with greater improvement in pain. However, on multivariate analyses the only significant independent predictors of persistent moderate to severe post-operative pain at 6 months were age and history of prior surgery. Further investigation is needed to determine whether pain catastrophizing is an innate patient factor with post-operative implications or merely an effect of prolonged symptoms in patellar instability patients.Table 1.Multivarite Linear regression model evaluating indepentant predictors of worse postoperative pain scores

Effects of pre‐surgical aerobic dance‐based exercise on lower extremity in people with morbid obesity awaiting bariatric surgery: Randomized controlled study

To investigate what are the effects of pre-surgical aerobic dance-based exercise programme (PSADBE) and physical activity counselling (PAC) programme on lower extremity functions after surgery in people with morbid obesity awaiting bariatric surgery (PMOABS). This study was a single-blind, randomized controlled study. Groups were divided into Group I (PSADBE and PAC) and Group II (PAC). Both groups received PAC, Group I completed the PSADBE programme accompanied by music for 60 min/2 days/8 weeks. Thirty-four PMOABS were included in the study. The 6-Minute Walking Test, as primary outcomes, and The Stair Climbing Up-Down Test for evaluating functional capacity, Biodex Isokinetic Test and Exercise System® for evaluating muscle strength were used. Besides, muscle endurance, physical activity (PA) level, fatigue and quality of life (QoL) were also assessed. All measurements were repeated three times; pre-treatment, post-treatment and the fifth-month post-surgery. After 8 weeks, significant changes were found in functional capacity, muscle strength and endurance, PA level, fatigue and QoL in both groups (p < .05). Comparing the groups, the changes in functional capacity, muscle strength and endurance, PA and fatigue scores after treatment and the fifth-month post-surgery were statistically superior in Group I (p < .05). Adding an 8-week PSADBE programme to PAC is an effective treatment option for improving postoperative functional capacity, muscle strength and endurance, PA level and fatigue in PMOABS.

Feasibility and Safety of Applying the Functional Electrical Stimulation to Child with Facioscapulohumeral Dystrophy: A Case Report

Aims This study aims to investigate the feasibility and safety of short-term functional electrical stimulation (FES) training of the quadriceps femoris muscles in a child with facioscapulohumeral muscular dystrophy (FSHD). Methods A 7-year-old child with FSHD received treatment due to a decrease in functional performance and difficulty climbing stairs. The child was followed up with a home-based exercise program. FES was applied twice a week during stair climbing for six weeks. Muscle activation of the quadriceps femoris was measured using superficial electromyography, muscle strength was measured with a hand-held dynamometer, and functional performance was assessed with the 6-Minute Walk and the Stair Climb Tests before and after the treatment period. Results At the end of the treatment, there was an improvement in muscle activation. While muscle strength increased in the quadriceps femoris muscle of the non-dominant side, it remained constant on the dominant side. Functional performance test results also improved. Conclusions FES was a feasible and safe tool to use in our case, a child with FSHD.

Falling Analysis and Examination of Different Novel Strategies for Preserving the Postural Stability of a User Wearing ASR-EXO during Stair Climbing

Falling Analysis and Examination of Different Novel Strategies for Preserving the Postural Stability of a User Wearing ASR-EXO during Stair Climbing

Effects of a 3-Week Inpatient Multidisciplinary Body Weight Reduction Program on Body Composition and Physical Capabilities in Adolescents and Adults With Obesity.

BackgroundThe aim of the present study was to examine the short-term changes in body composition and physical capabilities in subjects with obesity during a multidisciplinary inpatient body weight reduction program (BWRP).MethodsOne hundred thirty-nine adolescents (56 boys and 83 girls; BMI: 37.1 ± 6.5 kg/m2; Fat Mass, FM: 45.3 ± 7.2%) and 71 adults (27 males and 44 females; BMI: 44 ± 4.7 kg/m2; FM: 51.4 ± 4.7%) followed a 3-week inpatient BWRP consisting of regular physical activity, moderate energy restriction, nutritional education and psychological counseling. Before (T0) and after the end of the BWRP (T21), body composition was assessed with an impedancemeter, lower limb muscle power with Margaria Stair Climbing Test (SCT), lower limb functionality with Short Physical Performance Battery (SPPB), and the capacity of performing activity of daily living (ADL) with Physical Performance Test (PPT).ResultsAt T21, obese adolescents showed a 4% reduction in body mass (BM) (p < 0.001), associated with a FM reduction in boys (−10%) and girls (−6%) (p < 0.001) and with a 3% reduction in fat-free mass (FFM) recorded only in boys (p = 0.013). Obese adults showed a 5% BM reduction (p < 0.001), associated with a 2% FFM and 9% FM reduction (p < 0.001) in males, and 7% FM reduction in females (p < 0.001). Regarding physical capabilities, at T21 in obese adolescents, PPT score increased by 4% (p < 0.001), SCT decreased by −5% (boys) and −7% (girls) (p < 0.001), while SPPB score did not change significantly. In obese adults at T21, PPT score increased by 9% (p < 0.001), SCT decreased by −16% (p < 0.001) only in females, and SPPB score increased by 7% (males) and 10% (females) (p < 0.01).ConclusionIn conclusion, moderate energy restriction and regular physical activity determine a 4-5% BM reduction during a 3-week inpatient BWRP, improve physical capabilities and induce beneficial changes in body composition in adolescents and adults with obesity.Trial registrationThis study was approved by the Ethical Committee of the Istituto Auxologico Italiano (Milan, Italy; research code: 01C124; acronym: PRORIPONATFIS). Registered 11 November 2020 - Retrospectively registered.

Effects of Stair Climbing Training on Cardiopulmonary Endurance in Gym Users

Background: Stair climbing is an effective, easy to approach and inexpensive moderate to high intensity exercise with great effects in improving functional status of individuals.High intensity interval training (HIIT) protocol is also a short time exercise with greater long term effects in improving cardiopulmonary endurance. Aim: To examine the effects of stair climbing on cardiopulmonary endurance in gym users in addition to High intensity interval training (HIIT) protocol and to measure the effects of stair climbing on blood lactate in gym users. Methods: 32 healthy individuals including males and females have been divided into two groups all the participants were gym users from past three months .Control group followed HITT protocol only and experimental group performed stair climbing in addition to HIIT protocol. Time duration of the training was 8 weeks .Individuals were assessed before and after the training for VO2max, and blood lactate. Body Mass Index, Rate of Perceived Exertion, and O2cost, modified Canadian Aerobic Fitness Test (mCAFT) stages Blood Pressure, Heart Rate has also been assessed before and after training. Results: Results has shown the significant increase in VO2 max (p value 0.001) and lower levels of blood lactate (≤0.001) within the groups after training. There was no significant improvement in VO2max and blood lactate formation on comparison between the groups. Conclusion: Current study concluded that there was significant increase in VO2 max and blood lactate with stair climbing in addition to HIIT protocol in gym users within the groups but there is no significance between the groups. It means both the protocols been followed are significant with almost equal affects and both are equally beneficial. Keywords: Stair Climbing Training, High intensity interval training (HIIT), modified Canadian Aerobic Fitness Test (mCAFT)

Effectiveness of an individualized comprehensive rehabilitation program in women with chronic knee osteoarthritis: a randomized controlled trial.

To evaluate the short- and medium-term effects of an 8-week individualized comprehensive rehabilitation program in women with chronic knee osteoarthritis as regards functionality, physical performance, and perceived health status. Women with chronic knee osteoarthritis were randomly assigned to the aquatic training group or to the individualized comprehensive rehabilitation (ICR) group. The main outcomes were functionality assessed with the Western Ontario and McMaster Universities Osteoarthritis Index, physical performance assessed with the Timed Up and Go test and the Stair Climbing Test, and perceived health status evaluated with the European Quality of Life- 5 Dimensions questionnaire. Participants were assessed after the treatment and at 3-month follow-up. Forty participants were included in the study. After the treatment, there were no significant between- group differences. At 3-month follow-up, there were significant between-group differences in functionality (stiffness P = 0.049, function P = 0.005, and total subscores P = 0.048) and physical performance (Timed Up and Go P = 0.031 and Stair Climbing Test P = 0.046) in favor of the ICR group. An 8-week ICR program improved functionality, physical performance, and perceived health status compared with an aquatic training program in women with chronic knee osteoarthritis.

Influence of pain quality on physical performance in subjects with osteoarthritis of knee

Objectives Neuropathic pain features are frequently observed in subjects with knee osteoarthritis, which reduces their physical performance. This study was done to compare the physical performance between the subjects with neuropathic and nociceptive pain features. In addition, to assess the relationship between pain quality and physical performance in subjects with osteoarthritis of the knee. Methods Eighty subjects, ranging from 40 − 70 years of both genders with symptomatic and radiologically verified unilateral knee osteoarthritis (OA) were included for the study. Before having them in the study, all the subjects completed baseline interviews and demographic data. The subjects were categorized under neuropathic and nociceptive groups using Pain Detect Questionnaire (PDQ). One-time measurement of pain intensity, isometric strength of Quadriceps & hamstrings, and knee joint range of motion were assessed in both groups. Physical performance was measured using Osteoarthritis Research Society International recommended physical performance tests for knee osteoarthritis (40 m Fast Paced Walk Test, 6 min walk test, 30 s chair stand test, Timed up and Go Test, Stair Climb Test) and OA knee-related disability using Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire. Results Of the eighty subjects, forty subjects were included in the neuropathic group (44%), forty in the nociceptive group based on PDQ. Physical performance (p < 0.05) was significantly reduced in the neuropathic group. There existed a weak negative correlation between pain quality and variables measured (p < 0.05). Conclusion Physical performance was significantly reduced in OA knee subjects with neuropathic pain features. There is a negative correlation between pain quality and most of the physical performance variables.

TO COMPARE THE EFFECT OF BRISK WALK AND STAIR CLIMBING ON CARDIOPULMONARY ENDURANCE IN UNIVERSITY STUDENTS

To evaluate the effectiveness of brisk walking and stair climbing on cardiopulmonary endurance in university students. Methods: 28 (male=14, female=14) young healthy adults were recruited for this study. VO2max and BMI, baseline measures were taken before the follow up. Participants in stair climbing group were asked to climb 60 stairs (height= 15cm each step) comprises of three flights per bout and a total of 180 stairs per session; three days a week, for a total of 12 training sessions over 4 weeks. In group B participants were asked to walk briskly for least 20 min a day, 3 times a week, for a total of 12 sessions for four weeks. VO2max and BMI measures were taken after the follow up.Results: Out of a sample of 28 participants, In Group A (Stair Climbing) the age of participants was (21.86 ±1.45 years, BMI pre was 21.96±3.31 kg/m2, which decreased to BMI post was 21.93±3.29 kg/m2, VO2 max pre was 42.45±4.57 (mL.kg-1.min-1) and VO2 max post was increased to 46.07±4.51; mean ± SD). In Group B (Brisk Walking) the age of participants was (22.92±1.85 years, BMI pre was 22.03±2.75 kg/m2, BMI post was 21.53±1.93 kg/m2, VO2 max pre was 42.07±3.52 (mL.kg-1.min-1) and VO2 max post was increased to 43.84±3.36; mean ± SD). Conclusion: It is concluded from the study that stair climbing can improve cardiopulmonary endurance in young healthy university students as compared to the brisk walking.

STEP-UP: Enabling Low-Cost IMU Sensors to Predict the Type of Dementia During Everyday Stair Climbing

Posterior Cortical Atrophy is a rare but significant form of dementia which affects people's visual ability before their memory. This is often misdiagnosed as an eyesight rather than brain sight problem. This paper aims to address the frequent, initial misdiagnosis of this disease as a vision problem through the use of an intelligent, cost-effective, wearable system, alongside diagnosis of the more typical Alzheimer's Disease. We propose low-level features constructed from the IMU data gathered from 35 participants, while they performed a stair climbing and descending task in a real-world simulated environment. We demonstrate that with these features the machine learning models predict dementia with 87.02% accuracy. Furthermore, we investigate how system parameters, such as number of sensors, affect the prediction accuracy. This lays the groundwork for a simple clinical test to enable detection of dementia which can be carried out in the wild.

Gait Phase Subdivision and Leg Stiffness Estimation During Stair Climbing.

Leg stiffness is considered a prevalent parameter used in data analysis of leg locomotion during different gaits, such as walking, running, and hopping. Quantification of the change in support leg stiffness during stair ascent and descent will enhance our understanding of complex stair climbing gait dynamics. The purpose of this study is to investigate a methodology to estimate leg stiffness during stair climbing and subdivide the stair climbing gait cycle. Leg stiffness was determined as the ratio of changes in ground reaction force in the direction of the support leg Fl (leg force) to the respective changes in length Ll during the entire stance phase. Eight subjects ascended and descended an instrumented staircase at different cadences. In this study, the changes of leg force and length (force-length curve) are described as the leg stiffness curve, the slope of which represents the normalized stiffness during stair climbing. The stair ascent and descent gait cycles were subdivided based on the negative and positive work fluctuations of the center-of-mass (CoM) work rate curve and the characteristics of leg stiffness. We found that the leg stiffness curve consists of several segments in which the force-length relationship was similarly linear and the stiffness value was relatively constant; the phase divided by the leg stiffness curve corresponds to the phase divided by the CoM work rate curve. The results of this study may guide biomimetic control strategies for a wearable lower-extremity robot for the entire stance phase during stair climbing.

Predicting Individualized Joint Kinematics Over Continuous Variations of Walking, Running, and Stair Climbing.

Goal: Accounting for gait individuality is important to positive outcomes with wearable robots, but manually tuning multi-activity models is time-consuming and not viable in a clinic. Generalizations can possibly be made to predict gait individuality in unobserved conditions. Methods: Kinematic individuality-how one person's joint angles differ from the group-is quantified for every subject, joint, ambulation mode (walking, running, stair ascent, and stair descent), and intramodal task (speed, incline) in an open-access dataset with 10 able-bodied subjects. Four N-way ANOVAs test how prediction methods affect the fit to experimental data between and within ambulation modes. We test whether walking individuality (measured at a single speed on level ground) carries across modes, or whether a mode-specific prediction (based on a single task for each mode) is significantly more effective. Results: Kinematic individualization improves fit across joint and task if we consider each mode separately. Across all modes, tasks, and joints, modal individualization improved the fit in 81% of trials, improving the fit on average by 4.3[Formula: see text] across the gait cycle. This was statistically significant at all joints for walking and running, and half the joints for stair ascent/descent. Conclusions: For walking and running, kinematic individuality can be easily generalized within mode, but the trends are mixed on stairs depending on joint.

Relationship Between Life Space and Stair Climbing Among Community-Dwelling Older Adults

Relationship Between Life Space and Stair Climbing Among Community-Dwelling Older Adults

EFFECTIVENESS OF ISOKINETIC EXERCISE ON PAIN AND FUNCTION IN PATIENTS WITH TOTAL KNEE ARTHROPLASTY

Background: Relief of pain and physical function improvements normally happen in 6 to 12 months following total knee arthroplasty (TKA). Neverthless, pain persists in some patients even after one year. Likewise, functional improvement is insufficient. We have evaluated the effectiveness of an isokinetic strengthening program on post-operativelly (1-9 years) knee pain, funtional limitation, level walking and stair climbing in patients with TKA at late period. Methods: Twenty-five women patients with TKA were assigned into isokinetic training (study group) or the control groups. Patients answered WOMAC questionnaire and performed Stair Climbing Test. Quadriceps and hamstring muscle strength were evaluated isokinetically at 60 and 180°/sec angular velocity. All tests were evaluated before &amp; after intervention and at follow-up three months later. Only the study group performed isokinetic training five days a week for two weeks while both groups received home-based exercise program. Results: Knee pain at rest and during walking statistically decreased in both groups as per the evaluations at before &amp; after intervention and 3-month follow-up. Comparison of WOMAC scores in two groups revealed only a statistically significant decrease in the study group among the after intervention &amp; follow-up values. Although the increase at 60°/sec extension and flexion PT values in the study group was greater than that in the control group, there was no pointed difference between both groups. Conclusion: Strengthening of the knee muscles with isokinetic exercise reduces pain and improves functionality more than the home-based exercise program does.