Abstract

Hands-and-knees crawling, an effective rehabilitation method for children with motor impairments, requires precise phase detection for optimizing assistive devices. However, research on phase detection in human crawling remains limited. The research explores whether multijoint kinematic synergy (KS) features provide better accuracy than traditional time-domain (TD) features. Nine healthy adults participated in the study, where accelerometers and pressure sensors were used to capture motion and pressure data during crawling. The data were preprocessed and used to define four distinct phases of crawling, and kinematic synergy features were extracted using singular value decomposition-based principal component analysis (PCA). Machine learning models, including classification and regression trees (CART), K-nearest neighbors (KNN), and error-correcting output codes support vector machines (ECOC-SVM), were trained to recognize the crawling phases. Their performance was compared to that of traditional time-domain features. The phase recognition method based on multijoint kinematic synergies achieved an average accuracy of 89.37%. Specifically, the accuracy for CART was 88.41%, for KNN was 85.51%, and for ECOC-SVM was 94.20%. In comparison, the phase recognition using traditional time-domain features yielded lower accuracy, with overall accuracies of 75.36% for CART, 76.09% for KNN, and 85.51% for ECOC-SVM. The findings demonstrate that using multijoint kinematic synergy features significantly improves the accuracy of crawling phase recognition compared to traditional time-domain features. These recognized phases can be used to interpret the user's intent, which can then be integrated into exoskeleton control systems. In particular, high-level control systems can detect this intent and communicate it to lower-level systems, enabling precise motion commands. This integration holds promise for improving rehabilitation outcomes, especially for patients with conditions like cerebral palsy.

References

1.
WHO Multicentre Growth Reference Study Group
,
2006
, “
WHO Motor Development Study: Windows of Achievement for Six Gross Motor Development Milestones
,”
Acta Paediatr. (Oslo, Norway: 1992), Suppl.
,
450
, pp.
86
95
.10.1111/j.1651?2227.2006.tb02379.x
2.
Xiong
,
Q. L.
,
Wu
,
X. Y.
,
Liu
,
Y.
,
Zhang
,
C. X.
, and
Hou
,
W. S.
,
2021
, “
Measurement and Analysis of Human Infant Crawling for Rehabilitation: A Narrative Review
,”
Front. Neurol.
,
12
, p.
731374
(in English).10.3389/fneur.2021.731374
3.
McEwan
,
M. H.
,
Dihoff
,
R. E.
, and
Brosvic
,
G. M.
,
1991
, “
Early Infant Crawling Experience Is Reflected in Later Motor Skill Development
,”
Perceptual Mot. Skills
,
72
(
1
), pp.
75
79
(in English).10.2466/pms.1991.72.1.75
4.
Cole
,
W. G.
,
Vereijken
,
B.
,
Young
,
J. W.
,
Robinson
,
S. R.
, and
Adolph
,
K. E.
,
2019
, “
Use It or Lose It? Effects of Age, Experience, and Disuse on Crawling
,”
Dev. Psychobiol.
,
61
(
1
), pp.
29
42
(in English).10.1002/dev.21802
5.
Crouchman
,
M.
,
1986
, “
The Effects of Babywalkers on Early Locomotor Development
,”
Dev. Med. Child Neurol.
,
28
(
6
), pp.
757
–7
61
(in English).10.1111/j.1469-8749.1986.tb03929.x
6.
Yan
,
B.
, and
Ying
,
G. M.
,
2022
, “
Effect of Crawling Training on the Cognitive Function of Children With Cerebral Palsy
,”
Int. J. Rehabil. Res.
,
45
(
2
), pp.
184
188
.10.1097/MRR.0000000000000526
7.
Li
,
T.
,
Chen
,
X.
,
Cao
,
S.
,
Zhang
,
X.
, and
Chen
,
X.
,
2019
, “
Human Hands-and-Knees Crawling Movement Analysis Based on Time-Varying Synergy and Synchronous Synergy Theories
,”
Math. Biosci. Eng.: MBE
,
16
(
4
), pp.
2492
2513
.10.3934/mbe.2019125
8.
Chengxiang
,
L.
,
Xiang
,
C.
,
Xu
,
Z.
,
Xun
,
C.
, and
De
,
W.
,
2023
, “
Muscle Synergy Analysis of Eight Inter-Limb Coordination Modes During Human Hands-Knees Crawling Movement
,”
Front. Neurosci.
,
17
, p.
1135646
.10.3389/fnins.2023.1135646
9.
Bell
,
M. A.
, and
Fox
,
N. A.
,
1996
, “
Crawling Experience Is Related to Changes in Cortical Organization During Infancy: Evidence From EEG Coherence
,”
Dev. Psychobiol.
,
29
(
7
), pp.
551
561
(in English).10.1002/(SICI)1098-2302(199611)29:7<551::AID-DEV1>3.0.CO;2-T
10.
Yi
,
L.
, and
Zhang
,
L. F.
,
2013
, “
The Effect of Crawling Training on Lower Limb Function in Stroke Patients With Hemiplegia
,”
China Pract. Med.
,
8
(
22
), pp.
261
262
.10.3969/j.issn.1672-6731.2017.05.004
11.
FitCrawl
,
2023
, “
Your Total Body Workout
,” FitCrawl, Sydney, Australia, https://www.crawlfit.com.au/
12.
Ghazi
,
M. A.
,
Nash
,
M. D.
,
Fagg
,
A. H.
,
Ding
,
L.
,
Kolobe
,
T. H. A.
, and
Miller
,
D. P.
,
2016
, “
Novel Assistive Device for Teaching Crawling Skills to Infants
,”
Field and Service Robotics: Results of the 10th International Conference
,
D. S.
Wettergreen
and
T. D.
Barfoot
, eds.,
Springer International Publishing
,
Cham, Switzerland
, pp.
593
605
.
13.
Jiang
,
J. G.
,
Wang
,
C. C.
, and
Zhang
,
W. J.
,
2020
, “
Design and Analysis of a Parallel-Driven Rehabilitation Robot for Children With Cerebral Palsy
,”
Mech. Eng.
,
12
, pp.
1
3 + 6
.10.3390/machines11080787
14.
Kukreja
,
V.
,
Kumar
,
D.
, and
Kaur
,
A.
,
2021
, “
Deep Learning in Human Gait Recognition: An Overview
,”
2021 International Conference on Advance Computing and Innovative Technologies in Engineering
(
ICACITE
), Noida, India, March 4--5, pp.
9
13
.10.1109/ICACITE51222.2021.9404611
15.
Buchanan
,
T. S.
,
Lloyd
,
D. G.
,
Manal
,
K.
, and
Besier
,
T. F.
,
2004
, “
Neuromusculoskeletal Modeling: Estimation of Muscle Forces and Joint Moments and Movements From Measurements of Neural Command
,”
J. Appl. Biomech.
,
20
(
4
), pp.
367
395
.10.1123/jab.20.4.367
16.
Huang
,
L.
,
Zheng
,
J.
, and
Hu
,
H.
,
2022
, “
Online Gait Phase Detection in Complex Environment Based on Distance and Multi-Sensors Information Fusion Using Inertial Measurement Units
,”
Int. J. Soc. Rob.
,
14
(
2
), pp.
413
428
.10.1007/s12369-021-00794-6
17.
Zhu
,
L.
,
Wang
,
Z.
,
Ning
,
Z.
,
Zhang
,
Y.
,
Liu
,
Y.
,
Cao
,
W.
,
Wu
,
X.
, and
Chen
,
C.
,
2020
, “
A Novel Motion Intention Recognition Approach for Soft Exoskeleton Via IMU
,”
Electronics
,
9
(
12
), p.
2176
.10.3390/electronics9122176
18.
Zhang
,
Z.
,
Wang
,
Z.
,
Lei
,
W.
, and
Gu
,
W.
,
2022
, “
Gait Phase Recognition of Lower Limb Exoskeleton System Based on the Integrated Network Model
,”
Biomed. Signal Process. Control
,
76
, p.
103693
.10.1016/j.bspc.2022.103693
19.
Liu
,
D.-X.
,
Wu
,
X.
,
Du
,
W.
,
Wang
,
C.
, and
Xu
,
T.
,
2016
, “
Gait Phase Recognition for Lower-Limb Exoskeleton With Only Joint Angular Sensors
,”
Sensors
,
16
(
10
), p.
1579
.10.3390/s16101579
20.
Kyeong
,
S.
,
Feng
,
J.
,
Ryu
,
J. K.
,
Park
,
J. J.
,
Lee
,
K. H.
, and
Kim
,
J.
,
2022
, “
Surface Electromyography Characteristics for Motion Intention Recognition and Implementation Issues in Lower-Limb Exoskeletons
,”
Int. J. Control, Autom. Syst.
,
20
(
3
), pp.
1018
1028
.10.1007/s12555-020-0934-3
21.
Gao
,
F.
,
Tian
,
T.
,
Yao
,
T.
, and
Zhang
,
Q.
,
2021
, “
Human Gait Recognition Based on Multiple Feature Combination and Parameter Optimization Algorithms
,”
Comput. Intell. Neurosci.
,
2021
(
1
), p.
6693206
.10.1155/2021/6693206
22.
Su
,
B.
,
Smith
,
C.
, and
Farewik
,
E. G.
,
2020
, “
Gait Phase Recognition Using Deep Convolutional Neural Network With Inertial Measurement Units
,”
Biosensors-Basel
,
10
(
9
), p.
109
.10.3390/bios10090109
23.
Xing
,
H.
, and
Zhang
,
R.
,
2022
, “
Gait Recognition for Exoskeleton Robots Based on Improved KNN-DAGSVM Fusion Algorithm
,”
37th Youth Academic Annual Conference of Chinese Association of Automation
(
YAC
), Beijing, China, Nov. 19–20, pp.
364
369
.10.1109/YAC57282.2022
24.
Yan
,
H.
, and
Li
,
Z.
,
2022
, “
Optimization Algorithm of Gait Recognition Based on EMG Signal
,”
IEEE Second International Conference on Data Science and Computer Application
(
ICDSCA
), Dalian, China, Oct. 28–30, pp.
1405
1408
.10.1109/ICDSCA56264.2022
25.
Fangzheng
,
W.
,
Lei
,
Y.
, and
Jiang
,
X.
,
2019
, “
Recognition of the Gait Phase Based on New Deep Learning Algorithm Using Multisensor Information Fusion
,”
Sens. Mater.
,
31
(
10
), p.
3041
.10.18494/SAM.2019.2493
26.
Svonko
,
G.
,
Renato
,
B.
,
Mario
,
M.
,
Serena
,
P.
,
Salvatore
,
C. R.
, and
Marco
,
D. N. A.
,
2023
, “
Predicting Physical Activity Levels From Kinematic Gait Data Using Machine Learning Techniques
,”
Eng. Appl. Artif. Intell.
,
123
(
Pt. C
), p.
106487
.10.1016/j.engappai.2023.106487
27.
Wang
,
J.
,
Wang
,
Z.
,
Zhao
,
H.
, and
Qiu
,
S.
,
2016
, “
Human Motion Phase Segmentation Based on Three New Features
,”
IEEE 20th International Conference on Computer Supported Cooperative Work in Design
(
CSCWD
), Nanchang, China, May 4--6, pp.
647
652
.10.1109/CSCWD.2016.7565948
28.
Abhayasinghe
,
N.
, and
Murray
,
I.
,
2014
, “
Human Gait Phase Recognition Based on Thigh Movement Computed Using IMUs
,”
2014 IEEE Ninth International Conference on Intelligent Sensors, Sensor Networks and Information Processing
(
ISSNIP
), Singapore, Apr. 21–24, pp.
1
4
.10.1109/ISSNIP.2014.6827604
29.
Lai
,
Y. C.
,
Liao
,
H. Y. M.
,
Lin
,
C. C.
,
Chen
,
J. R.
, and
Luo
,
Y. F. P.
,
2009
, “
A Local Feature-Based Human Motion Recognition Framework
,”
IEEE International Symposium on Circuits and Systems
, Taipei, Taiwan, May 24–27, pp.
722
725
.10.1109/ISCAS.2009.5117850
30.
To
,
C. S.
,
Kirsch
,
R. F.
,
Kobetic
,
R.
, and
Triolo
,
R. J.
,
2005
, “
Simulation of a Functional Neuromuscular Stimulation Powered Mechanical Gait Orthosis With Coordinated Joint Locking
,”
IEEE Trans. Neural Syst. Rehabil. Eng.
,
13
(
2
), pp.
227
235
(in English).10.1109/TNSRE.2005.847384
31.
Dejnabadi
,
H.
,
Jolles
,
B. M.
, and
Aminian
,
K.
,
2008
, “
A New Approach for Quantitative Analysis of Inter-Joint Coordination During Gait
,”
IEEE Trans. Biomed. Eng.
,
55
(
2
), pp.
755
764
.10.1109/TBME.2007.901034
32.
Safavynia
,
S.
,
Torres-Oviedo
,
G.
, and
Ting
,
L.
,
2011
, “
Muscle Synergies: Implications for Clinical Evaluation and Rehabilitation of Movement
,”
Top. Spinal Cord Injury Rehabil.
,
17
(
1
), pp.
16
24
.10.1310/sci1701-16
33.
Ting
,
L. H.
, and
McKay
,
J. L.
,
2007
, “
Neuromechanics of Muscle Synergies for Posture and Movement
,”
Curr. Opin. Neurobiol.
,
17
(
6
), pp.
622
628
.10.1016/j.conb.2008.01.002
34.
Tresch
,
M. C.
,
Saltiel
,
P.
, and
Bizzi
,
E.
,
1999
, “
The Construction of Movement by the Spinal Cord
,”
Nat. Neurosci.
,
2
(
2
), pp.
162
167
.10.1038/5721
35.
Shuaijie
,
W.
,
YiChung
,
P.
, and
Tanvi
,
B.
,
2021
, “
Kinematic Synergies in Over-Ground Slip Recovery Outcomes: Distinct Strategies or a Single Strategy?
,”
Gait Posture
,
95
, pp.
270
276
.10.1016/j.gaitpost.2021.01.025
36.
Yusuke
,
S.
,
Dai
,
O.
,
Keita
,
H.
, and
ShinIchi
,
I.
,
2022
, “
Kinetic Interjoint Coordination in Lower Limbs During Gait in Patients With Hemiparesis
,”
Biomechanics
,
2
(
3
), pp.
466
477
.10.3390/biomechanics2030036
37.
Burns
,
M. K.
,
Patel
,
V.
,
Florescu
,
I.
,
Pochiraju
,
K. V.
, and
Vinjamuri
,
R.
,
2017
, “
Low-Dimensional Synergistic Representation of Bilateral Reaching Movements
,”
Front. Bioeng. Biotechnol.
,
5
, p.
2
(in English).10.3389/fbioe.2017.00002
38.
Troje
,
N. F.
,
2002
, “
Decomposing Biological Motion: A Framework for Analysis and Synthesis of Human Gait Patterns
,”
J. Vision
,
2
(
5
), pp.
371
387
(in English).10.1167/2.5.2
39.
Gentner
,
R.
, and
Classen
,
J.
,
2006
, “
Modular Organization of Finger Movements by the Human Central Nervous System
,”
Neuron
,
52
(
4
), pp.
731
742
(in English).10.1016/j.neuron.2006.09.038
40.
Yang
,
J.
,
Lu
,
Z.
,
Chen
,
S.
,
Liu
,
C.
, and
Zhao
,
H.
,
2024
, “
Continuous Knee Joint Angle Prediction With Surface EMG
,”
Biomed. Signal Process. Control
,
95
, p.
106354
.10.1016/j.bspc.2024.106354
41.
Li
,
X.
, and
Chen
,
L.
,
2021
, “
Kinematic Compatibility Recognition and Angle Tracking Control for Lower Limb Exoskeleton
,”
Fifth International Conference on Robotics and Automation Sciences
(
ICRAS
), IEEE, Wuhan, China, June 11–13, pp.
150
154
.10.1109/ICRAS52289.2021.9476287
42.
Schwartz
,
E.
,
Guidry
,
K.
,
Lee
,
A.
,
Dinh
,
D.
,
Levin
,
M. F.
, and
Demers
,
M.
,
2022
, “
Clinical Motor Coordination Tests in Adult Neurology: A Scoping Review
,”
Physiother. Can.
,
74
(
4
), pp.
387
395
(in English).10.3138/ptc-2021-0025
43.
Xiong
,
Q.
,
Wan
,
J.
,
Liu
,
Y.
,
Wu
,
X.
,
Jiang
,
S.
,
Xiao
,
N.
, and
Hou
,
W.
,
2024
, “
Reduced Corticospinal Drive to Antagonist Muscles of Upper and Lower Limbs During Hands-and-Knees Crawling in Infants With Cerebral Palsy: Evidence From Intermuscular EMG-EMG Coherence
,”
Behav. Brain Res.
,
457
, p.
114718
.10.1016/j.bbr.2023.114718
44.
Xiong
,
Q. L.
,
Hou
,
W. S.
,
Xiao
,
N.
,
Chen
,
Y. X.
,
Yao
,
J.
,
Zheng
,
X. L.
,
Liu
,
Y.
, and
Wu
,
X. Y.
,
2018
, “
Motor Skill Development Alters Kinematics and Co-Activation Between Flexors and Extensors of Limbs in Human Infant Crawling
,”
IEEE Trans. Neural Syst. Rehabil. Eng.
,
26
(
4
), pp.
780
787
.10.1109/TNSRE.2017.2785821
45.
Robertson
,
D. G. E.
, and
Dowling
,
J. J.
,
2003
, “
Design and Responses of Butterworth and Critically Damped Digital Filters
,”
J. Electromyogr. Kinesiol.
,
13
(
6
), pp.
569
573
.10.1016/S1050-6411(03)00080-4
46.
Widmann
,
A.
,
Schröger
,
E.
, and
Maess
,
B.
,
2015
, “
Digital Filter Design for Electrophysiological Data—A Practical Approach
,”
J. Neurosci. Methods
,
250
, pp.
34
46
.10.1016/j.jneumeth.2014.08.002
47.
Sun
,
M.
,
Lan
,
L.
,
Zhu
,
C.-G.
, and
Lei
,
F.
,
2023
, “
Cubic Spline Interpolation With Optimal End Conditions
,”
J. Comput. Appl. Math.
,
425
, p.
115039
.10.1016/j.cam.2022.115039
48.
Li
,
X.
,
Liu
,
J.
,
Huang
,
Y.
,
Wang
,
D.
, and
Miao
,
Y.
,
2022
, “
Human Motion Pattern Recognition and Feature Extraction: An Approach Using Multi-Information Fusion
,”
Micromachines (Basel)
,
13
(
8
), p.
1205
(in English).10.3390/mi13081205
49.
Samuel
,
O. W.
,
Zhou
,
H.
,
Li
,
X.
,
Wang
,
H.
,
Zhang
,
H.
,
Sangaiah
,
A. K.
, and
Li
,
G.
,
2018
, “
Pattern Recognition of Electromyography Signals Based on Novel Time Domain Features for Amputees' Limb Motion Classification
,”
Comput. Electr. Eng.
,
67
, pp.
646
655
.10.1016/j.compeleceng.2017.04.003
50.
Tkach
,
D.
,
Huang
,
H.
, and
Kuiken
,
T. A.
,
2010
, “
Study of Stability of Time-Domain Features for Electromyographic Pattern Recognition
,”
J. NeuroEng. Rehabil.
,
7
(
1
), p.
21
.10.1186/1743-0003-7-21
51.
Berk
,
R. A.
,
2016
, “
Classification and Regression Trees (CART)
,”
Statistical Learning From a Regression Perspective
,
R. A.
Berk
, ed.,
Springer International Publishing
,
Cham, Switzerland
, pp.
129
186
.
52.
Eltanani
,
S.
,
Scheper
,
T. O.
, and
Dawes
,
H.
,
2021
, “
K-Nearest Neighbor Algorithm: Proposed Solution for Human Gait Data Classification
,”
IEEE Symposium on Computers and Communications
(
ISCC
), Athens, Greece, Sept. 5--8, pp.
1
5
.10.1109/ISCC53001.2021.9631454
53.
Liu
,
Q.
,
Sun
,
W.
,
Peng
,
N.
,
Meng
,
W.
, and
Xie
,
S. Q.
,
2024
, “
DCNN-SVM-Based Gait Phase Recognition With Inertia, EMG, and Insole Plantar Pressure Sensing
,”
IEEE Sens. J.
,
24
(
18
), pp.
28869
28878
.10.1109/JSEN.2024.3435884
54.
Sun
,
B.
,
Zhang
,
Z.
,
Liu
,
X.
,
Hu
,
B.
, and
Zhu
,
T.
,
2017
, “
Self-Esteem Recognition Based on Gait Pattern Using Kinect
,”
Gait Posture
,
58
, pp.
428
432
.10.1016/j.gaitpost.2017.09.001
55.
Huang
,
B.
,
Xiong
,
C.
,
Chen
,
W.
,
Liang
,
J.
,
Sun
,
B. Y.
, and
Gong
,
X.
,
2021
, “
Common Kinematic Synergies of Various Human Locomotor Behaviours
,”
R. Soc. Open Sci.
,
8
(
4
), p.
210161
(in English).10.1098/rsos.210161
56.
Nancy
,
S.-O.
, and
Feldman
,
A. G.
,
2003
, “
Interjoint Coordination in Lower Limbs During Different Movements in Humans
,”
Exp. Brain Res.
,
148
(
2
), pp.
139
–1
49
.10.1007/s00221-002-1212-8
57.
Tagliabue
,
M.
,
Ciancio
,
A. L.
,
Brochier
,
T.
,
Eskiizmirliler
,
S.
, and
Maier
,
M. A.
,
2015
, “
Differences Between Kinematic Synergies and Muscle Synergies During Two-Digit Grasping
,”
Front. Human Neurosci.
,
9
, p.
165
.10.3389/fnhum.2015.00165
58.
Zheng
,
G.
,
Qian
,
Z.
,
Yang
,
Q.
,
Wei
,
C.
,
Xie
,
L.
,
Zhu
,
Y.
, and
Li
,
Y.
,
2008
, “
The Combination Approach of SVM and ECOC for Powerful Identification and Classification of Transcription Factor
,”
BMC Bioinf.
,
9
(
1
), p.
282
.10.1186/1471-2105-9-282
59.
Liu
,
M.
,
Zhang
,
D.
,
Chen
,
S.
, and
Xue
,
H.
,
2016
, “
Joint Binary Classifier Learning for ECOC-Based Multi-Class Classification
,”
IEEE Trans. Pattern Anal. Mach. Intell.
,
38
(
11
), pp.
2335
2341
.10.1109/TPAMI.2015.2430325
60.
Roman
,
I.
,
Santana
,
R.
,
Mendiburu
,
A.
, and
Lozano
,
J. A.
,
2021
, “
In-Depth Analysis of SVM Kernel Learning and Its Components
,”
Neural Comput. Appl.
,
33
(
12
), pp.
6575
6594
.10.1007/s00521-020-05419-z
61.
Gao
,
F.
,
Liu
,
G.
,
Liang
,
F.
, and
Liao
,
W. H.
,
2020
, “
IMU-Based Locomotion Mode Identification for Transtibial Prostheses, Orthoses, and Exoskeletons
,”
IEEE Trans. Neural Syst. Rehabil. Eng.
,
28
(
6
), pp.
1334
1343
.10.1109/TNSRE.2020.2987155
62.
Derlatka
,
M.
, and
Bogdan
,
M.
,
2015
, “
Ensemble kNN Classifiers for Human Gait Recognition Based on Ground Reaction Forces
,”
Eighth International Conference on Human System Interaction
(
HSI
), Warsaw, Poland, June 25--27, pp.
88
93
.10.1109/HSI.2015.7170648
63.
Gao
,
Q.
,
Ding
,
X.
,
Li
,
C.
, and
Qi
,
Z. T.
,
2023
, “
A Gait Recognition of EMG Signal Method Based on Bat Algorithm Optimized KNN
,” Seventh Asian Conference on Artificial Intelligence Technology (
ACAIT
), Jiaxing, China, Nov. 10–12, pp.
16
20
.10.1109/ACAIT60137.2023.10528639
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