Uses of Phantom Sensations Induced by Global and Local Modifications of the Prosthetic Socket as Somatosensory Feedback During Walking in Lower Limb Amputees
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 228
- 试验地点
- 2
- 主要终点
- Characterization of phantom limb sensations
研究概览
简要总结
Following lower-limb amputation, the loss of somatosensory information from the missing limb renders walking less automatic, more cognitively demanding, and often asymmetric, which can lead to secondary pathologies.
Hypothesis: This study is based on the hypothesis that phantom limb sensations (PLS), when coherent with the prosthetic device's movements and the phases of the gait cycle, can compensate for the loss of somatosensory feedback and thereby improve locomotion for individuals with amputation. It is further hypothesized that it is possible to artificially induce these coherent and useful sensations, notably through "referred sensations" elicited by stimulation of the residual limb (e.g., via the prosthetic socket).
Objectives: The project aims to:
- Determine whether the natural presence of phantom limb sensations during walking impacts gait parameters.
- Confirm in a larger patient population that modifications to the prosthetic socket can induce or enhance phantom sensations that are perceived as useful for walking.
- Investigate whether these perceptual changes (induced or enhanced) are associated with objective, measurable improvements in gait quality.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Sequential
- 主要目的
- Health Services Research
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Participants with amputations:
- •Major lower limb amputation
- •Understand and be able to express oneself in the French language (for semi-structured interviews)
- •Affiliated with a social security scheme
- •Asymptomatic volunteer participants:
- •No major surgery on the lower limbs for at least 3 years
- •No minor injury to the trunk, lower or upper limbs that could influence walking for at least 1 year
- •Understand and be able to express oneself in the French language
- •Affiliated with a social security scheme
排除标准
- •History of psychiatric disorders
- •Pregnant or breastfeeding woman
- •Adult subject to a legal protection measure
- •Person under guardianship or conservatorship
- •Person under a judicial protection order
- •Pain affecting walking (trunk, residual limb, phantom limb, contralateral limb)
- •Medical treatment incompatible with walking
结局指标
主要结局
Characterization of phantom limb sensations
时间窗: The first day of the study
A composite assessment of phantom limb sensations will be conducted via a semi-structured interview. Data collected will include: * Type of sensation (e.g., tingling, pain, movement). * Location (toes, heel, calf). * Intensity (Mild, Strong, Very Strong).
Walking speed under laboratory conditions
时间窗: The first day of the study for the control group and the second day of the study for participants with amputation
The participant's average walking speed, measured in meters per second (m/s). The measurement will be collected using inertial measurement units (IMUs) and/or a Vicon motion capture system while the participant walks on hard ground or on a treadmill at their self-selected speed.
Step length symmetry index.
时间窗: The first day of the study for the control group and the second day of the study for participants with amputation
Gait symmetry will be calculated based on the stride length of the affected (or corresponding) limb and the healthy limb. The symmetry index is a unitless ratio (or percentage) that quantifies the difference between the two limbs. A value of 1 (or 100%) indicates perfect symmetry. Measured using inertial measurement units or the Vicon system.
Changes in the surface area of sensory maps referred to the residual limb
时间窗: 2nd or 3rd day of the study depending on whether the participant with an amputation was included in phase 2 or not and during the 6-month follow-up visit.
The total surface area capable of triggering phantom sensations will be measured. For each type of stimulation (brush, pressure, point, electrical), the number of 3x3 cm areas causing a sensation will be counted. The total surface area (in cm²) will be calculated by multiplying this number by 9. A map will be generated for each stimulation modality.
Change in the spatiotemporal parameters of walking in ecological situations
时间窗: Days 4 to 7 to the study
Several key walking parameters (speed in m/s, cadence in steps/min, step symmetry index) will be measured using inertial sensors during the outdoor walk. The analysis will compare the average values of these parameters between the four socket conditions.
Change in the average intensity of reported phantom sensations.
时间窗: 2nd or 3rd day of the study depending on whether the participant with an amputation was included in phase 2 or not and during the 6-month follow-up visit.
When each reactive area is stimulated, the participant will rate the intensity of the phantom sensation perceived on a 6-point Numerical Rating Scale (NRS), ranging from 0 (no sensation) to 5 (maximum intensity imaginable). The average intensity of the reactive areas will be calculated for each type of stimulation.
Localization of the cortical source of somatosensory evoked potentials (SEPs) during stimulation of referred sensation areas
时间窗: The second day of the study for participants with amputation
The recorded EEG activity will be used to model and locate the source of the maximum cortical response. The primary outcome measure will be the coordinates (e.g., in the MNI or Talairach atlas) of the center of activation in the somatosensory cortex. The objective is to compare the source localization obtained during ecological gait after each demanding walking situation.
Participant's subjective preference for one of the four socket conditions tested.
时间窗: Day 7 of the study
At the end of the four test sessions, participants will be asked to rank the four conditions (rigidity A/B, with/without focal pressure) from most to least conducive to walking. The primary outcome will be the condition ranked first by the largest number of participants.
次要结局
- Walking pace under laboratory conditions(The first day of the study for the control group and the second day of the study for participants with amputation)
- Analysis of brain activity related to cognitive load during walking(The second day of the study for participants with amputation)
- Gait speed in ecological situation(The first day of the study for the control group and the second day of the study for participants with amputation)
- Qualitative description of the interaction between phantom sensations and walking(The second day of the study for participants with amputation)
- Change in phantom limb sensation intensity at 6 months for recent amputees(The first day of the study and during the 6-month follow-up visit.)
- Effect of focal stimulation on phantom sensations(Day 3 of the study)
- Change in perceived cognitive load (NASA-TLX score) during walking in an ecological setting(Day 4 to 7 of the study)
- Evaluation of socket comfort(Day 4 to 7 of the study)
- Analysis of muscle co-activation in the lower limbs and trunk during walking.(The first day of the study for the control group and the second day of the study for participants with amputation)
- Maximum vertical reaction force during walking.(The first day of the study for the control group and the second day of the study for participants with amputation)
- Assessment of mental workload during walking using the NASA-TLX questionnaire(The first day of the study for the control group and the second day of the study for participants with amputation)
- Qualitative description of the sensations reported for each socket condition(Day 4 to 7 of the study)