Effect of observation on lower limb prosthesis gait biomechanics: Preliminary results

Background: The Hawthorne effect, a subcategory of reactivity, causes human behavior to change when under observation. Such an effect may apply to gait variation of persons with prosthetics or orthotics devices. Objectives: This study investigated whether the presence of observers directly affects the gait pattern of users of lower limb prostheses. Study design: Within-subject intervention study. Methods: Primary outcome measures were gait parameters of initial double support time and upper body lateral tilt angle, which were collected with a mobile sensor attached to the subjects’ back. To make subjects feel unwatched, a certain amount of deception was necessary, and two different conditions were created and statistically compared against each other: one in which the subjects were initially unaware of the attention of observers and another one in which the same subjects were aware of a group of observers. Results: Data from two subjects using trans-femoral prosthesis are reported. Findings included a change in step initial double support percentage by up to 14.2% ( p = 0.019). Considerable changes were also noted in secondary outcome measures including speed, stride length, and stride symmetry. Conclusions: A reactivity effect of observation exists in prosthetics gait analysis. More comprehensive studies may be motivated by these preliminary findings. Clinical relevance Results of this study suggest that users of lower limb prostheses walk differently when their gait is being assessed (e.g. in the prosthetist’s office) than in situations without observers. This may in part explain the clinical experience that modifications of prosthetic fit or alignment provide only short-term betterment.

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Effects of Torso Pitch Motion on Energy Efficiency of Biped Robot Walking

Applied Sciences ◽

10.3390/app11052342 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2342

Author(s):

Long Li ◽

Zhongqu Xie ◽

Xiang Luo ◽

Juanjuan Li

Keyword(s):

Energy Efficiency ◽

Energy Consumption ◽

Biped Robot ◽

Gait Pattern ◽

Pattern Generation ◽

Biped Robots ◽

Pitch Motion ◽

Double Support ◽

Gait Parameters ◽

Support Phase

Gait pattern generation has an important influence on the walking quality of biped robots. In most gait pattern generation methods, it is usually assumed that the torso keeps vertical during walking. It is very intuitive and simple. However, it may not be the most efficient. In this paper, we propose a gait pattern with torso pitch motion (TPM) during walking. We also present a gait pattern with torso keeping vertical (TKV) to study the effects of TPM on energy efficiency of biped robots. We define the cyclic gait of a five-link biped robot with several gait parameters. The gait parameters are determined by optimization. The optimization criterion is chosen to minimize the energy consumption per unit distance of the biped robot. Under this criterion, the optimal gait performances of TPM and TKV are compared over different step lengths and different gait periods. It is observed that (1) TPM saves more than 12% energy on average compared with TKV, and the main factor of energy-saving in TPM is the reduction of energy consumption of the swing knee in the double support phase and (2) the overall trend of torso motion is leaning forward in double support phase and leaning backward in single support phase, and the amplitude of the torso pitch motion increases as gait period or step length increases.

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Analysis of the spatio-temporal gait parameters of transtibial amputees

Visión electrónica ◽

10.14483/22484728.18386 ◽

2018 ◽

Vol 1 (2) ◽

pp. 247-253

Author(s):

Yuliana Ruiz-Piragauta ◽

Brigette Paola Torres-Bello ◽

Esperanza Camargo-Casallas

Keyword(s):

Lower Limb ◽

Stride Length ◽

Inertial Sensors ◽

Step Length ◽

Gait Pattern ◽

Gait Parameters ◽

Length Step ◽

Spatio Temporal ◽

Antipersonnel Mines ◽

Transtibial Amputees

In this study we analyzed the spatio-temporal parameters (step length, step time, stride length, stride time, speed and rate) of three unilateral transtibial amputees in order to find the best gait pattern and this verify the adaptation of the prosthesis, using inertial sensors of the TECHNAID ® brand in order to make the diagnosis in an objective way; the data were processed using the MARCHA ET software of the DIGITI research group of the Universidad Distrital Francisco José de Caldas. In this study, were analyzed three subjects from the Hospital Militar Central (HMC) the cause of amputation is due to trauma caused by antipersonnel mines. It was found that subjects with unilateral transtibial amputation lean on more time and carry more weight on their healthy lower limb, which leads to an increase in mechanical demand on the knee joint of the amputated leg.

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Identifying gait quality metrics sensitive to changes in lower limb constraint

10.21203/rs.3.rs-544297/v1 ◽

2021 ◽

Author(s):

Kinsey Herrin ◽

Samuel Kwak ◽

Young-Hui Chang

Keyword(s):

Lower Limb ◽

Parameter Tuning ◽

Gait Pattern ◽

Quality Metrics ◽

Tuning Parameters ◽

Quality Metric ◽

Gait Quality ◽

Gait Deviation Index ◽

Lower Limb Prosthesis ◽

Multiple Metrics

Abstract Background Manual tuning of robotic lower limb prostheses can be time consuming for both the patient and the clinician and requires in-person visits to a clinic. An automated process for the tuning parameters of a robotic lower limb prosthesis could result in a substantial savings in healthcare resources. A critical challenge to an automated parameter tuning algorithm is the quantification of a person’s gait quality. There is not good agreement in the literature of an objective outcome measure that can rapidly assess gait quality in lower limb amputees. As a first step, we investigated the ability of four common gait quality metrics to detect differences in gait quality: Prosthetic Observational Gait Score (POGS), Gait Deviation Index (GDI), Lateral Sway, and Impulse Asymmetry. Methods We systematically applied four unilateral lower limb joint constraint conditions (baseline/no constraint, ankle constraint, knee constraint, and knee + ankle constraint) to nine able-bodied participants walking at three different speeds (0.7, 0.85 and 1.0 m/s). We calculated and compared the resulting GDI, POGS, Lateral Sway and Impulse Asymmetry scores across all conditions. We performed a 2-way ANOVA statistical analysis to compare sensitivity of the metrics to the various conditions with significance defined by an alpha-level = 0.05. Results The Lateral Sway metric distinguished three joint constraint conditions and two of the speed conditions. Both GDI and POGS were able to distinguish four out of six possible constraint-speed conditions, while Impulse Asymmetry was only able to detect differences between three of the six constraint-speed conditions. Conclusions No single gait quality metric could distinguish every condition. Accordingly, a single metric of gait quality may be inadequate for tuning a prosthesis and therefore multiple metrics and sensors may provide the best results for tuning a prosthesis to the most natural gait pattern for an individual. Compared to the more complex gait measures, Lateral Sway performed well as a simple metric that might easily be operationalized into a real-time parameter tuning controller.

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Potential and Limitations of Feedback-Supported Gait Retraining in Users of Lower Limb Prostheses

Prosthesis ◽

10.3390/prosthesis3020018 ◽

2021 ◽

Vol 3 (2) ◽

pp. 181-189

Author(s):

Kaitlyn Marie Rayl ◽

Goeran Fiedler

Keyword(s):

Lower Limb ◽

Patient Characteristics ◽

Target Population ◽

Long Term Effects ◽

Gait Retraining ◽

Rehabilitation Programs ◽

Published Evidence ◽

Gait Parameters ◽

Feedback Modalities ◽

Lower Limb Prostheses

The outcomes of prosthetic rehabilitation after lower limb loss are, in large part, affected by the effectiveness of the provided gait retraining. The noted prevalence of adverse long-term effects, such as further joint and muscle degeneration, suggests that traditional rehabilitation programs have limitations. Recent advances in technology and in the understanding of motor learning promise the potential for better gait retraining interventions. This article reviews current literature on systems and methodologies of improving gait parameters in those with lower limb prostheses via exercise programs and various biofeedback systems. A total of 13 articles were included in the qualitative analysis. Findings indicate that many of the investigated systems are able to effectively analyze and change gait in the target population, but there remain considerable gaps in the knowledge. It has been noted that feedback modalities and dosage must be customized based on patient characteristics and rehabilitation goals, yet there is currently not enough published evidence to inform such customization.

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Examination of Tactor Configurations for the Design of Vibrotactile Feedback Systems for Use in Lower-Limb Prostheses

Volume 8: 30th Conference on Mechanical Vibration and Noise ◽

10.1115/detc2018-85197 ◽

2018 ◽

Cited By ~ 2

Author(s):

Sam Shi ◽

Matthew J. Leineweber ◽

Jan Andrysek

Keyword(s):

Lower Limb ◽

Negative Relationship ◽

Feedback System ◽

Elevated Pressure ◽

Intensity Level ◽

Response Accuracy ◽

Feedback Systems ◽

Vibrotactile Feedback ◽

Lower Limb Prosthesis ◽

Lower Limb Prostheses

Vibrotactile feedback may be able to compensate for the loss of sensory input in lower-limb prosthesis users. Designing an effective vibrotactile feedback system would require that users could perceive and correctly respond to vibrotactile stimuli applied by the tactors. Our study explored three key tactor configuration variables (i.e. vibratory intensity, prosthetic pressure, spacing between adjacent tactors) through two experiments. The vibration propagation experiment investigated the effects of tactor configurations on vibratory amplitude at the prosthesis-limb interface. Results revealed a positive relationship between vibratory amplitude and intensity, and a negative relationship between vibratory amplitude and prosthetic pressure. The vibrotactile perception experiment investigated the effects of tactor configurations on user response accuracy, and found that greater spacing between tactors, and higher prosthetic pressure resulted in more accurate responses from the subjects. These findings inform the design of a vibrotactile feedback system for use in lower-limb prostheses: 1) the tactors may be best placed in areas of slightly elevated pressure at the prosthesis-limb interface; 2) a higher vibratory intensity level should improve performance for vibrotactile feedback systems; and 3) more spacing between adjacent tactors improves user response accuracy.

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A Lower Limb Prosthesis Haptic Feedback System for Stair Descent

2017 Design of Medical Devices Conference ◽

10.1115/dmd2017-3409 ◽

2017 ◽

Cited By ~ 2

Author(s):

Astrini Sie ◽

Jonathan Realmuto ◽

Eric Rombokas

Keyword(s):

Lower Limb ◽

Haptic Feedback ◽

The Body ◽

Lower Limbs ◽

Prosthetic Limbs ◽

Stair Descent ◽

Lower Limb Prosthesis ◽

Limb Prosthesis ◽

Flat Ground ◽

Lower Limb Prostheses

Though there are a variety of prosthetic limbs that address the motor deficits associated with amputation, there has been relatively little progress in restoring sensation. Prosthetic limbs provide little direct sensory feedback of the forces they encounter in the environment, but “closing the loop” between sensation and action can make a great difference in performance [1]. For users of lower limb prostheses, stair descent is a difficult and dangerous task. The difficulty in stair descent can be attributed to three different factors: 1) Absence of tactile and haptic sensations at the bottom of the foot. Although force on the prosthetic socket provides some haptic feedback of the terrain being stepped on, this feedback does not provide information on the location of the staircase edge. 2) Insufficient ankle flexion of lower limb prostheses. Dorsiflexion of the physiological ankle during stair descent is about 27°. Even prostheses that provide active dorsiflexion provide less than this number, and regular prostheses provide almost no ankle dorsiflexion. The first two factors are analogous to the sensation of stair descent for someone without amputation wearing ski boots. 3) Prosthetic feet are optimized for flat-ground walking, offering undesirable energy storage at ankle flexion and energy return at toe-off. This can result in unwanted extra energy at the end of stance phase, propelling the user forward down the stairs. Most lower limb prosthesis designs focus on flat ground walking, but there has been less progress in addressing the challenges of stair descent. One technique that users of prosthetic lower limbs can use for addressing these challenges is to employ an “overhanging toe” foot placement strategy. Under this strategy, the edge of the staircase is used as a pivot point for the foot to roll over the stair. This reduces the need for ankle flexion by allowing the knee and hip to compensate, and avoids storing energy in the prosthetic spring. This strategy is dynamic, and requires the user to know the amount of toe overhang to adjust the movement of the rest of the body. Most haptic devices built to assist individuals wearing prostheses focus on upper extremity tasks [2–4] or standing and walking [5,6]. Whereas previous lower limb sensory replacement systems have targeted standing measures, here we focus on stair descent. The system provides cues of the stair edge location via vibrotactile stimulations on the thigh.

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Analysis of biomechanical gait parameters in patients after total hip replacement operated via anterolateral approach depending on size of the femoral head implant: retrospective matched-cohort study

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-021-04264-6 ◽

2021 ◽

Author(s):

Artur Stolarczyk ◽

Magda Stolarczyk ◽

Łukasz Oleksy ◽

Grzegorz J. Maciąg ◽

Piotr Stępiński ◽

...

Keyword(s):

Femoral Head ◽

Total Hip Replacement ◽

Hip Replacement ◽

Gait Pattern ◽

Head Size ◽

Anterolateral Approach ◽

Double Support ◽

Total Hip ◽

Gait Parameters ◽

Patient Reported

Abstract Introduction Total hip replacement (THR) is considered one of the most effective medical procedures in treatment of osteoarthritis. Since its introduction, there has been a worldwide debate over proper implant selection in terms of size, bearing type and shape. Following study was designed to assess the importance of femoral head size in long-term follow-up. Materials and methods A cohort of 30 patients with primary end stage osteoarthritis who underwent total hip replacement was analysed retrospectively. A homogenous group was chosen with no major differences in BMI. Patients’ gait parameters were measured in a biomechanics laboratory using the 3D BTS Smart system. WOMAC and VAS questionnaires were used to assess patient reported outcome. Results The subgroup with larger implant head size had several outcomes significantly superior to the subgroup with standard head size and non-inferior to healthy hips. Following variables were measured during this study: time of support phase, time of swing phase, double support time, walking hip extension angle. Conclusions Use of larger sized femoral heads during THR gives better results in terms of gait pattern. Since restoring the gait pattern is one of the aspects of rehabilitation and returning to daily activities it seems to be an important observation.

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Computed dynography, a method for evaluation of gait pattern in treated cases of congenital talipes equino varus

International Journal of Research in Orthopaedics ◽

10.18203/issn.2455-4510.intjresorthop20201105 ◽

2020 ◽

Vol 6 (3) ◽

pp. 611

Author(s):

Akshay Jain ◽

Adhir Jain ◽

Ravi Kant Jain ◽

Prateek Pathak

Keyword(s):

Ground Reaction Force ◽

Reaction Force ◽

Gait Pattern ◽

Vertical Ground Reaction Force ◽

Age And Gender ◽

Double Support ◽

Gait Parameters ◽

Vertical Ground ◽

Congenital Talipes ◽

And Gender

Background: Club foot is characterized by inversion, adduction and equinus. Currently, evaluation of children treated for congenital talipes equino varus (CTEV) includes clinical and radiological examination as well as assessment of function. However, none of the methods is ideal. There should be objective methods for better evaluation of function in treated CTEV. Gait analysis is the emerging method in objectively assessing the functional outcome. The aim of the study was to compare the selected measures from vertical ground reaction force variables and gait parameters of treated CTEV children with plantigrade feet, to healthy age and gender matched control group.Methods: We took 31 children with treated CTEV with mean age 8.21 years and compared with 31 age and gender matched controls. The patients were initially treated under a standard protocol. Gait cycle properties, step time parameters and vertical ground reaction force variables were recorded and comparison of unilateral and bilateral cases of treated CTEV was done with that of controls.Results: Data showed that despite good clinical results and overall function, residual intoeing, lateral foot walking, mild foot drop, weak plantar flexor power, possible residual inversion deformity of the foot, increased frequency and decreased duration of cycle and asymmetry in gait were the main characteristics of gait of children with treated CTEV. In unilateral cases single and double support times were decreased and in bilateral CTEV double support times are increased.Conclusions: The study confirms that in clubfoot patients who underwent full treatment, gait parameters do not reach normal levels. Gait analysis can be used to quantify gait pattern characteristics and is helpful in evaluation and further development of treatment of patients.

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Analysis and construction of a prosthetic foot

I+D Tecnológico ◽

10.33412/idt.v14.1.1805 ◽

2018 ◽

Vol 14 (1) ◽

pp. 76-82

Author(s):

John Alexander Hernández Martin ◽

Luis Parra Piñero ◽

César Pinzón Pinzón ◽

Oscar Bejarano Peña ◽

Jairo Romero Gutiérrez ◽

...

Keyword(s):

Lower Limb ◽

Personal Characteristics ◽

Gait Pattern ◽

Activity Level ◽

Lower Limbs ◽

Rehabilitation Process ◽

Prosthetic Foot ◽

Lower Limb Prosthesis ◽

Transfemoral Prosthesis ◽

Limb Prosthesis

The assistive devices for people with disabilities are configured as a set of mechanical, electromechanical, orthotic and prosthetic parts designed to assist in the rehabilitation process of patients who suffered amputation of their lower limbs, whether the injury generates The implementation of a transtibial or transfemoral prosthesis these elements must be performed with proper analysis of pre-amputation, amputation and post amputation in order to achieve specific objectives for each patient, achieving the best possible treatment. It is important to ensure that in the treatment of lower limb disability by amputation, the best decisions are generated for the patient, with the objective of bringing the patient closer to a normal gait pattern. Considering these characteristics it will be possible to elaborate a prosthetic element that meets the physical and personal characteristics of the patient such as activity level, age, weight ... etc. Taking into account each of these variables we have decided to analyze in depth a crucial element in the implementation of lower limb prosthesis such as the foot, which we carry from a phase of analysis, design, to implementation in carbon fiber where we currently perform tests with our patients under study.

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Assessment of gait in patients with fibromyalgia during motor and cognitive dual task walking: a cross-sectional study

Advances in Rheumatology ◽

10.1186/s42358-021-00212-5 ◽

2021 ◽

Vol 61 (1) ◽

Author(s):

Goran Radunović ◽

Zoran Veličković ◽

Melanija Rašić ◽

Saša Janjić ◽

Vladana Marković ◽

...

Keyword(s):

Functional Status ◽

Dual Task ◽

Stride Length ◽

Clinical Symptoms ◽

Gait Pattern ◽

Dual Tasks ◽

Double Support ◽

Gait Parameters ◽

Double Support Time ◽

Support Time

Abstract Background The aim of the study was to assess gait pattern of patients diagnosed with fibromyalgia (FM) while performing demanding motor and/or cognitive dual tasks while walking. Further, idea was to explore possible correlations of dual task gait pattern alterations to patients’ functional status and presence or absence of clinical symptoms associated with FM. Methods Twenty-four female FM patients and 24 healthy female subjects performed a basic walking task, a dual motor, a dual mental (cognitive) and a combined, dual motor and cognitive task simultaneously. Quantitative spatial (stride length) and temporal (cycle time, swing time and double support time) gait parameters were measured using GAITRite walkway system and their variability was assessed. Patients underwent clinical examination including assessment of functional status, pain and fatigue level, psychiatric and cognitive manifestations. Results The motor, cognitive and combined dual tasks affect gait performance in FM patients. Difference in tasks between FM and healthy subjects was found as double support time prolongation. Comparison of tasks showing that cycle time in FM was longer than controls and stride length was shorter in patients for all conditions, while no changes were found in any of the gait parameters variability. Further, mental/cognitive dual tasks had a larger effect than motor tasks. Correlations were also found between depression and functional status of the patients and the gait parameters. Conclusions Gait is affected in FM patients while dual task walking. No changes in stride-to-stride variability point that patients preserve stability in complex walking situations. Analysis of gait may provide additional information for the FM identification based on presence of clinical features and cognitive status. Correlation of dual task gait alterations with occurrence of clinical symptoms and influence of cognitive changes on gait pattern could additionally define FM subgroups.

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