GENERAL INFORMATION

Authors: Cristina Rossi(a,b), Ryan T. Roemmich(b,c), Amy J. Bastian(a,b,)
(a) Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA;
(b) Center for Movement Studies, Kennedy Krieger Institute, Baltimore, MD, 21205, USA;
(c) Department of Physical Medicine and Rehabilitation, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
() Corresponding author: Amy J. Bastian. Email: bastian@kennedykrieger.org

Please cite this data as follows:
Rossi et al., 2023. Dataset for Understanding mechanisms of generalization following locomotor adaptation.

Paradigm information: kinematic and behavioral test data was collected in a human walking experiment on a split-belt treadmill.
Details are found in the associated manuscript.

Acknowledgments:
Supported by NIH grant 5 R37 NS090610 to AJB,
American Heart Association predoctoral fellowship 20PRE35180131 to CR.

SOURCE DATA

raw task data + standardly processed kinematic measures

Location: ‘data’ folder

Info: contains .mat data files with ‘raw’ kinematic measures and behavioral tasks measures for all participants in the study.

Files: one file per experimental group

• ShortPreferred.mat (group of Experiment 1)
• LongPreferred.mat (group of Experiment 1)
• ShortSlow.mat (group of Experiment 1)
• SwitchSlow.mat (group of Experiment 2)
• SwitchControl.mat (group of Experiment 2)

Variables: each group file contains a variable with the same name, which is a struct containing the following fields:

├─── Measures recorded once per experiment:
|              ├─── Trials: a table with N rows, N=number of experimental trials for this group. Has 3 columns:
|                   |             ├─── Environment: string with information on whether the trial was overground ('OG') or on the treadmill ('TM')
|                   |                   ├─── Condition: string with corresponding experimental phase ('Baseline', 'Adaptation', 'Catch', 'Post-adaptation')
|                   |                   └─── Task: string with information on whether the trial was followed by a speed match task
|                   |
|              └─── Questionnaire: 1xN Trials cell, the cell corresponding to the post-adapt. OG trial contains:
|                          N Participants X 2 matrix, containing participants response to whether the right leg felt it was moving:
|                         "as expected" (coded as 0), or "not as expected" (coded as 1) (first column: "beginning of this trial", second column: "end of this trial")
\|                                    	(Experiment 1 only)
|
├─── Kinematic measures computed by stride:
|               │                                 *  each of the following fields is a (1 x N Trials) cell,
\|                   │                           	          with each cell element a (N Participants X N Strides in Trial) matrix,
|               │	                                     with each element in the matrix a sample of that measure for the specific trial, participant and stride)
|               │
\|                   │                           	     * The following variables/abbreviations are used for kinematic measures:
|               │\
|               │                                         Legs:
|               │	                                           f = "fast" leg = leg positioned on the belt that is fast in adaptation
\|                   │	                                           s = "slow" leg = leg positioned on the belt that is slow in adaptation
\|                   │
\|                   │	                                       Markers:
|               │                                             toe5 = fifth metatarsal head
\|                   │                                             ankle = lateral malleolous
\|                   │                                             knee = lateral femoral epicondyle
\|                   │                                             trochanter = greater trochanter
\|                   │
|               │	                                       Gait events:
\|                   │	                                           shs = slow heel strike
\|                   │	                                           fhs = fast heel strike
\|                   │	                                           sto = slow toe off
\|                   │	                                           fto = fast toe off
\|                   │	                                           (heel strikes/toe offs are detected as the positive/negative peaks in ankle anterior-posterior position for that leg)
\|                   │
|               ├─── SLA: step length asymmetry
\|                   │                                                (Units: normalized, unitless)\
\|                   │                                                (Definition: (fast step length - slow step length)/(fast step length + slow step length),
\|                   │                                                             fast step length = anterior-posterior distance between feet at fast heel strike,
\|                   │                                                             slow step length = anterior-posterior distance between feet at slow heel strike)\
\|                   │                                                (see manuscript for details; computed for all groups)
|               │
|               ├─── joint angles at gait events (ShortPreferred only; see manuscript for definition):
|               │                                                                         shs_fAnkleAngle, shs_sHipAngle, shs_sKneeAngle, shs_sAnkleAngle, shs_fHipAngle, shs_fKneeAngle,
\|                   │                                                                         fto_fAnkleAngle, fto_sHipAngle, fto_sKneeAngle, fto_sAnkleAngle, fto_fHipAngle, fto_fKneeAngle,
|               │                                                                         fhs_fAnkleAngle, fhs_sHipAngle, fhs_sKneeAngle, fhs_sAnkleAngle, fhs_fHipAngle, fhs_fKneeAngle,
|               │                                                                         sto_fAnkleAngle, sto_sHipAngle, sto_sKneeAngle, sto_sAnkleAngle, sto_fHipAngle, sto_fKneeAngle\
\|                   │                                                           (Units: degrees)\
|               │                                                           (Overall variable name is defined as [gait event]*[leg][joint]Angle =
|               │* *                           *                                             angle of the [joint] of the [leg] measured at [gait event])
*|               │*  *                           *                               (Overall variable name, example: sto_fAnkleAngle = fast leg ankle angle [fAnkleAngle] at slow toe off [sto])
*|               │*  *                           *                               (Angle definitions:
*|               │*  *                           *Ankle = angle between knee, ankle, toe5 markers,
|               │*  *                           *                                                     0deg if ankle-toe5 segment is perpendicular to the ankle-knee segment,
*|               │*  *                           *                                                     dorsiflexion is positive;
*|               │*  *                           *Hip = angle of the trochanter-knee segment relative to a vertical line,
|               │*  *                           *0deg if the segment is vertical,
|               │*  *                           *flexion is positive;\
|               │*  *                           *Knee = angle between trochanter, knee, ankle markers,
|               │*  *                           *0deg if the knee is fully extended (the three markers are in a line)
|               │*  *                           *flexion is positive.)
|               │*  *                          * 
*|               ├─── joint marker position at gait events (ShortPreferred only; see manuscript for definition):
|               │*  *                           *shs_sAnkleX, shs_sKneeX, shs_sTrochanterX, shs_fTrochanterX, shs_fKneeX, shs_fAnkleX,
|               │*  *                           * fto_sAnkleX, fto_sKneeX, fto_sTrochanterX, fto_fTrochanterX, fto_fKneeX, fto_fAnkleX,
*|               │*  *                           * fhs_fAnkleX, fhs_fKneeX, fhs_fTrochanterX, fhs_sTrochanterX, fhs_sKneeX, fhs_sAnkleX,
*|               │*  *                           * sto_fAnkleX, sto_fKneeX, sto_fTrochanterX, sto_sTrochanterX, sto_sKneeX, sto_sAnkleX,
*|               │*  *                           * shs_sAnkleY, shs_sKneeY, shs_sTrochanterY, shs_fTrochanterY, shs_fKneeY, shs_fAnkleY,
*|               │*  *                           * fto_sAnkleY, fto_sKneeY, fto_sTrochanterY, fto_fTrochanterY, fto_fKneeY, fto_fAnkleY,
*|               │*  *                           * fhs_fAnkleY, fhs_fKneeY, fhs_fTrochanterY, fhs_sTrochanterY, fhs_sKneeY, fhs_sAnkleY,
*|               │*  *                           * sto_fAnkleY, sto_fKneeY, sto_fTrochanterY, sto_sTrochanterY, sto_sKneeY, sto_sAnkleY\
*|               │*  *                           * (Units: meters)\
*|               │*  *                           * (Overall variable name is defined as [gait event][leg][joint][coordinate] =
|               │  *                            position of the [joint] marker of the [leg] measured at [gait event], along axis [coordinate])\
|               │  *                            (Coordinates: X = anterior-posterior, forward is positive; Y = vertical, upward is positive;\
|               │  *                            all positions are expressed relative to the hip center position =\
|               │  *                            the average of the fast and slow trochanter markers for each frame)
|               │  *                           \
|               └─── support times (ShortPreferred only; see manuscript for definition): dstF, sstS, dstS, sstF\
|                                                                                 (Units: seconds)\
|                                                                                 (Abbreviations:\
|                                                                                        dstF = fast double support = time from shs to fto,\
|                                                                                       sstS = slow single support = time from fto to fhs,\
|                                                                                       dstS = slow double support = time from fhs to sto,\
|                                                                                       sstF = fast single support = time from sto to shs)
|\
├─── Timeseries measures at 100Hz
|               │  *                            * each of the following fields is a (1 x N Trials) cell,
|               │  *                                     with each cell element a (N Participants X N frames in Trial) matrix,
|               │  *                                     with each element in the matrix a sample of that measure for the specific trial, participant and timestamp
|               │  *                           \
|               │  *                                 * The following abbreviations/definitions are used:
|               │*  *                            slowlead: variables referring to strides that are defined as the period between two consecutive SLOW heel strikes\
|               │*  *                            fastlead: variables referring to strides that are defined as the period between two consecutive FAST heel strikes\
|               │*  *                            (these are support/dummy variables used for plotting within-leg gait cycle measures)
|               │*  *                           
|               ├─── timeseries_slowlead_stride, timeseries_fastlead_stride (ShortPreferred only):
|               │*  *                            (Definition: stride number, for strides defined using "slowlead" or "fastlead" definitions above)
|               │*  *                           \
|               ├─── timeseries_slowlead_Sstance, timeseries_slowlead_Fstance, timeseries_fastlead_Sstance, timeseries_fastlead_Fstance (ShortPreferred only):
|               │*  *                            (Definition: flag (0: swing, 1: stance) for whether S(slow) or F(fast) foot is in stance,
|               │*  *                            for strides defined using "slowlead" or "fastlead" definitions above)
|               │*  *                           \
|               ├─── timeseries_sHipAngle, timeseries_sKneeAngle, timeseries_sAnkleAngle, timeseries_fHipAngle, timeseries_fKneeAngle, timeseries_fAnkleAngle (ShortPreferred only):
|               │*  *                            (Units: degrees)
|               │*  *                            (Definition: joint angles for each frame, defined as described in the "kinematic measures" above)
|               │*  *                           \
|               ├─── timeseries_slowlead_pass, timeseries_fastlead_pass (ShortPreferred, overground trials only):
|               │*  *                            (Definition: overground pass number, for strides defined using "slowlead" or "fastlead" definitions above)
|               │*  *                           
|               ├─── TaskTime (all groups):
|               │*  *                            (Units: seconds)
|               │*  *                            (Definition: time stamp for the TaskRightSpeed measure)
|               │*  *                           \
|               └─── TaskRightSpeed (all groups):
|                          (Units:  meters/seconds)
|                         (Definition: speed of the right belt)
|\
|\
├─── Measures recorded once per overgorund pass:\
|                    │       (1 x N Trials) cell,\
|                │	         with each cell element a N Participants X N Overground Passes in that trial,\
|                    │	         with each element in the matrix a sample of that measure for the specific Overground pass & participant.
|                    │
|                    └─── OvergroundSpeed: walking speed for that overground pass
|                                          (Units: meters/seconds)
|\
└─── Measures recorded once per trial:
│                      (1 x N Speed Match Tasks) cell,
│               	         with each cell element a N Participants X 1 matrix,
│	                        with each element in the matrix a sample of that measure for the specific task & participant.
│
└─── TaskRightSpeedFinal: speed of the right belt at the end of each iteration of the speed match task\
               (Units: meters/seconds)

CODE

Location: ‘code’ folder

Info: Contains .m code files for data analysis [all files are saved with .m extension]

Files:

->Main File: “RunAll.m” calls all files in the correct order

->Files used for Background Computations (computing .mat files in analyses folder):

E123_bootstrapSamples
	% %% E123_bootstrapSamples.m
	% %% Experiments 1, 2 and 3. 
	% %% creates bootstrap samples of participants for each group 
	% %% (10,000 samples of N participants, N=group size)
	% %% Output: .mat file with participants indexes for each bootstrap sample
	% %% in analyses\[groupname]BootstrapSamples.mat

E3_ComputeInterpolatedAngles
	% %% E3_ComputeInterpolatedAngles.m
	% %% Experiment 3. 
	% %% computes interpolated angles, by stride, averaged over strides for each epoch of interest
	% %% Output: .mat file with variables 'interpolatedAngleData' (interpolated angles in deg)
	% %%      and 'interpolatedAngleEvents' (interpolated HS and TO, % of stride times)
	% %% in analyses\ShortPreferred_InterpolatedAngleData.mat

E3_ComputeOGChange
	% %% E3_ComputeOGChange.m
	% %% Related to Experiment 3
	% %% computes OG baseline to post-adaptation change for different kinematics  
	% %% Output 1: computes epoch difference for segment lengths at to/hs events 
	% %% Output 2: computes epoch difference for joint angles at to/hs events 
	% %% Output 3: computes epoch difference for support times 
	% %% in analyses\ShortPreferred_EpochData.mat, struct epochData 

->Files used for Figures and Stats:

E1_PlotsAndStats
	% %% E1_PlotsAndStats.m
	% %% Related to Experiment 1, Fig. 1, 2, 3, S1, S2, S3, and Stats #1, 2, 3
	% %% plots and statistics for E1    
	% %% Output #1. Fig. 1B & S2A,B Top. SLA Timeseries
	% %% Output #2. Fig. S1C & S2A,B Bottom. R-L Speed at the end of each iteration of the speed match tasks
	% %% Output #3. Fig. 2D. R Speed in speed match tasks (BL mean, post-adapt, post-OG) Timeseries for ShortPreferred.
	% %% Output #4. Fig. 2D & 3E. Post-adapt. overground perceptual questionnaire
	% %% Output #5. Fig. 1C, 2D, 3B-C-D-F, S1A-B, S2C-D, and Stats #1-2, generalization and OG block characteristics measures
	% %% Output #6. Fig. S3 and Stats #3, individual OG speeds 

E2_PlotsAndStats
	% %% E2_PlotsAndStats.m
	% %% Related to Experiment 2, Fig. 4, 5, S4, and Stats #4, 5
	% %% plots and statistics for E2
	% %% Output #1. Fig. 4C, S4A-B.  SLA Timeseries
	% %% Output #2. Fig. 5B. R-L Speed at the end of each iteration of the speed match tasks
	% %% Output #3. Fig. 4C right, 5C, S4C-D, and Stats #4-5. Generalization and OG block characteristics measures

E3_AnglePlots
	% %% E3_AnglePlots.m
	% %% Related to Experiment 3, Fig. 6A, S6, S7, S8
	% %% Output: Plots of Knee Vs Hip angle traces

E3_BarPlotsAndStats
	% %% E3_BarPlotsAndStats.m
	% %% Related to Experiment 3, Fig. 6A insets, 6B insets, Stats 6-7
	% %% Output 1: Plots support times 
	% %% Output 2: Plots and Stats for segment angles and support times 
	% %%    in 'stats\Stats6_E3_Epochs.csv'
	% %% Output 3: Plots and stats for peak angles
	% %%    in 'stats\Stats7_E3_PeakAngles.csv'

E3_ProjectionPlots
	% %% E3_ProjectionPlots.m
	% %% Related to Experiment 3, Fig. S5
	% %% Output: Plots bird-eye view projections of limb segments for all epochs

E3_SegmentPlots
	% %% E3_SegmentPlots.m
	% %% Related to Experiment 3, Fig. 6B
	% %% Output: Plots stick figures of limb segments for each epoch

->Background helper files are located both in the main “code” folder, as well as the “lib” subfolder folder

GENERATED FILES

files obtained processing source data with code provided

ANALYSED DATA
-> data obtained processing source data with code provided

Location: ‘analyses’ folder

Info: Contains .mat data files generated from the code and the source data provided in other folders.
Analysed data is an intermediate steps to plotting figures and computing statistics

STATS
-> .csv files with computed stats

Location: ‘stats’ folder

Info: Contains .csv files for selected statistical comparisons (involving a large number of results / presented in tables; other stats are included in figure generation)