Biomechanical Assessment of Gait in Lower-Extremity-Amputees | NCT01332123

NCT01332123

Protocol Section

Identification Module

Results Section

Participant Flow Module

Annotation Section

No data available

No data is available for this block.

Document Section

No data available

No data is available for this block.

Derived Section

Miscellaneous Info Module

Status Module

Oversight Module

Description Module

Detailed Description

In amputee walking, an optimal static alignment of the artificial leg is important in order to achieve the best possible performance. Comfort, energy expenditure, mobility and walking speed should ideally be similar to those of able bodied persons. Of course, amputation level, overall health status and other factors often pose certain individual limitations that may prevent an amputee from reaching this goal.

Irrespective of that, the artificial leg must be aligned properly to eliminate unnecessary inhibitions. Apart from manufacturing a well fitting socket, and selecting the appropriate functional components of the prosthesis, the prosthetist has to routinely optimize the static alignment during the fitting process. Hereby, objective measures and guidelines are scarce. Despite various more or less useful tools that are available, the alignment optimization in praxis is often based on subjective gait assessment and rules of thumb. Commonly accepted is the notion, that the gait pattern should be most symmetrically, that is step lengths, stance times, knee angles etc. should be identical between sound and prosthetic leg.

There are different questions that our study wants to address: Is gait symmetry indeed a valid measure of prosthetic performance (e.i. is it the most energy efficient way to walk)? How does the gait pattern change when the prosthesis user walks on different surfaces, becomes tired or tries to compensate for a less-than-optimal prosthesis fit? How can gait symmetry be objectively assessed without using an expensive motion analysis laboratory? We hope that our findings will provide practically useful information that can help improve prosthetic fittings in the field.

The study will be based on data from up to 15 trans-tibial prosthesis users. Participants will walk with their standard prosthesis, which will be equipped with a small sensor unit for the measurement of forces and moments during walking. The muscle activity of the thigh muscles will be measured using surface EMG sensors. All of the data collection will take place at the USR facilities (115 E Reindl Way, Milwaukee), where a multi camera motion analysis system is set up. Trials will require an overall time commitment of 5 hours at most, and will include normal walking, walking on carpet and gravel, walking up and down stairs, walking with fatigued thigh muscles.

Design Module

Interventional Study Design

Biospecimen

No data available

No data is available for this block.

Arms/Interventions Module

Arm Groups

Label	Type	Description	Intervention Names
Alignment perturbations	Experimental	The following modifications will be applied to the prostheses: increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation (always 2 degrees from the neutral position)	Device: Alignment perturbations

Interventions

Name	Type	Description	Arm Group Labels	Other Names
Alignment perturbations	Device	Increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation (always 2 degrees from the neutral position)

Outcomes Module

Primary Outcomes

Measure	Description	Time Frame
Overall Asymmetry Index	Gait data was continuously recorded and was post processed to determine symmetry between left and right legs. Symmetry was computed by dividing the difference between legs by the average of both legs. 0 marks perfect symmetry and greater values higher asymmetry. There is no maximum limit. The overall asymmetry index was calculated as the mean of the following: max knee flex, dorsi flexion, plantar flexion (1st and 2nd peak), knee moment, dorsi-flexion moment, plantar-flexion moment, times of max in % of the gait cycle, Stance phase % of gait cycle and step length. The kinematics asymmetry index was calculated as the mean of the following: maximal knee flex, dorsi flexion, plantar flexion (1st and 2nd peak), the times of max in % of the gait cycle, Stance phase % of gait cycle and step length. The kinetics asymmetry index was calculated as the mean of the following variables: knee moment, dorsi-flexion moment, plantar-flexion moment, the times of max in % of the gait cycle.	1 hour

Secondary Outcomes

Measure	Description	Time Frame
Heart Rate Change	Subjects were wearing a wireless heart rate monitor. The respective readings were noted and assessed during and immediately following the trials to estimate individual exertion rates. Changes in heart rate between resting and exertion across the sample were investigated to be able to interpret the primary outcome measures and to discuss limitations of the protocol. Unequal exertion rates within the sample would cause uneven trends biomechanical changes that are related to exertion.

Eligibility Module

Name	Affiliation	Role
Brooke A Slavens, PhD	UWM CHS	Principal Investigator

Facility	Status	City	State	ZIP	Country	Contacts
USR, 115 E Reindl Way		Milwaukee	Wisconsin	53211	United States

Arm/Group Information

ID	Title	Description
FG000	Alignment Perturbations	The following modifications were applied to the prostheses: increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation, increased foot outward rotation, increased foot inward rotation (always 15 degrees from the neutral position) Alignment perturbations: Increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation, increased foot outward rotation, increased foot inward rotation (always 15 degrees from the neutral position)

Baseline Characteristics Module

Arm/Group Information

ID	Title	Description
BG000	Alignment Perturbations	The following modifications were applied to the prostheses: increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation, increased foot outward rotation, increased foot inward rotation (always 15 degrees from the neutral position) Alignment perturbations: Increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation, increased foot outward rotation, increased foot inward rotation (always 15 degrees from the neutral position)

Units	Counts
Participants	BG000

Title	Description	Population Description	Parameter Type	Dispersion Type	Unit of Measure	Calculate Percentage	Denominator Units Selected	Denominators	Classes
Age, Continuous			Mean

Outcome Measures Module

Outcome Measures

Type	Title	Description	Population Description	Reporting Status	Anticipated Posting Date	Parameter Type	Dispersion Type	Unit of Measure	Calculate Percentage	Time Frame	Units Analyzed	Denominator Units Selected	Arm/Group Information	Denominators	Classes	Analyses
Primary	Overall Asymmetry Index	Gait data was continuously recorded and was post processed to determine symmetry between left and right legs. Symmetry was computed by dividing the difference between legs by the average of both legs. 0 marks perfect symmetry and greater values higher asymmetry. There is no maximum limit. The overall asymmetry index was calculated as the mean of the following: max knee flex, dorsi flexion, plantar flexion (1st and 2nd peak), knee moment, dorsi-flexion moment, plantar-flexion moment, times of max in % of the gait cycle, Stance phase % of gait cycle and step length. The kinematics asymmetry index was calculated as the mean of the following: maximal knee flex, dorsi flexion, plantar flexion (1st and 2nd peak), the times of max in % of the gait cycle, Stance phase % of gait cycle and step length. The kinetics asymmetry index was calculated as the mean of the following variables: knee moment, dorsi-flexion moment, plantar-flexion moment, the times of max in % of the gait cycle.	Two of the recruited participants were not included in the analysis, as they had bilateral amputations. Bilateral amputation was not posted as an exclusion criteria initially, but posted unanticipated limitations during data collection and analysis.	Posted		Mean	Standard Deviation	unit-less index (0 = perfect symmetry)		1 hour

Adverse Events Module

Arm/Groups

ID	Title	Description	Deaths (Affected)	Deaths (At Risk)	Serious Events (Affected)	Serious Events (At Risk)	Other Events (Affected)	Other Events (At Risk)
EG000	Alignment Perturbations	The following modifications were applied to the prostheses: increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation (always 2 degrees from the neutral position) Alignment perturbations: Increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation (always 2 degrees from the neutral position)

Term	Organ System	Source Vocabulary	Assessment Type	Notes	Statistical Information
Exertion	General disorders				EG000

Title	Organization	Phone	Extension	Email
Goeran Fiedler	university of pittsburgh	4126246475		gfiedler@pitt.edu

ID	Title	Description
OG000	Alignment Perturbations	The following modifications were applied to the prostheses: increased foot plantar flexion, increased foot dorsal flexion, increased foot supination, increased foot pronation (always 2 degrees from the neutral position) All participants were subjected to the same 5 interventions (neutral alignment and 4 perturbations as detailed above) in sequence to allow repeated measures (within-subject) comparisons.