scholarly journals Correction: McGrath, T., et al. An Auto-Calibrating Knee Flexion-Extension Axis Estimator using Principal Component Analysis with Inertial Sensors. Sensors 2018, 18(6), 1882

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1504
Author(s):  
Timothy McGrath ◽  
Richard Fineman ◽  
Leia Stirling
Keyword(s):  
Principal Component Analysis ◽  
Knee Flexion ◽  
Inertial Sensors ◽  
Principal Component ◽  
Component Analysis ◽  
Flexion Extension ◽  
Extension Axis

The authors wish to make the following revisions to this paper [...]

Knee Angles After Crosstalk Correction With Principal Component Analysis in Gait and Cycling

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Jordan Skaro ◽  
Scott J. Hazelwood ◽  
Stephen M. Klisch
Keyword(s):  
Principal Component Analysis ◽  
Knee Flexion ◽  
External Rotation ◽  
Principal Component ◽  
Component Analysis ◽  
Motion Analysis System ◽  
High Flexion ◽  
Flexion Extension ◽  
Analysis System ◽  
Post Hoc

Abstract Principal component analysis (PCA) has been used as a post-hoc method for reducing knee crosstalk errors during gait analysis. PCA minimizes correlations between flexion–extension (FE), abduction–adduction (AA), and internal–external rotation (IE) angles. However, previous studies have not considered PCA for exercises involving knee flexion angles that are greater than those typically experienced during gait. Thus, the goal of this study was to investigate using PCA to correct for crosstalk during one exercise (i.e., cycling) that involves relatively high flexion angles. Fifteen participants were tested in gait and cycling using a motion analysis system. Uncorrected FE, AA and IE angles were compared to those calculated with PCA performed on (1) all angles (FE-AA-IE PCA correction) and (2) only FE-AA angles (FE-AA PCA correction). Significant differences existed between uncorrected and FE-AA-IE PCA corrected AA and IE angles for both exercises, between uncorrected and FE-AA PCA corrected AA angles for both exercises, and between FE-AA-IE and FE-AA PCA corrected IE angles for cycling. Correlations existed before PCA correction and were eliminated following PCA correction with the exception that FE-IE correlations remained following FE-AA PCA correction. Since the two PCA analyses differed only in their IE angle predictions for the high flexion exercise (cycling), IE angle results were compared to previous studies. Using FE-AA PCA correction may be the preferred protocol for cycling as it appeared to retain physiological IE angle correlations at high flexion angles. However, there exists a critical need for studies aimed at obtaining more accurate IE angles in such exercises.

scholarly journals Assessment of walker-assisted gait based on Principal Component Analysis and wireless inertial sensors

2014 ◽  
Vol 30 (3) ◽  
pp. 220-231 ◽  
Author(s):  
Maria Martins ◽  
Arlindo Elias ◽  
Carlos Cifuentes ◽  
Manuel Alfonso ◽  
Anselmo Frizera ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Inertial Sensors ◽  
Principal Component ◽  
Component Analysis

scholarly journals The application of principal component analysis to characterize gait and its association with falls in multiple sclerosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrew S. Monaghan ◽  
Jessie M. Huisinga ◽  
Daniel S. Peterson
Keyword(s):  
Multiple Sclerosis ◽  
Principal Component Analysis ◽  
Dynamic Stability ◽  
Fear Of Falling ◽  
Inertial Sensors ◽  
Principal Component ◽  
Component Analysis ◽  
Functional Mobility ◽  
Timed Up And Go ◽  
Trunk Motion

AbstractPeople with multiple sclerosis (PwMS) demonstrate gait impairments that are related to falls. However, redundancy exists when reporting gait outcomes. This study aimed to develop an MS-specific model of gait and examine differences between fallers and non-fallers. 122 people with relapsing–remitting MS and 45 controls performed 3 timed up-and-go trials wearing inertial sensors. 21 gait parameters were entered into a principal component analysis (PCA). The PCA-derived gait domains were compared between MS fallers (MS-F) and MS non-fallers (MS-NF) and correlated to cognitive, clinical, and quality-of-life outcomes. Six distinct gait domains were identified: pace, rhythm, variability, asymmetry, anterior–posterior dynamic stability, and medial–lateral dynamic stability, explaining 79.15% of gait variance. PwMS exhibited a slower pace, larger variability, and increased medial–lateral trunk motion compared to controls (p < 0.05). The pace and asymmetry domains were significantly worse (i.e., slower and asymmetrical) in MS-F than MS-NF (p < 0.001 and p = 0.03, respectively). Fear of falling, cognitive performance, and functional mobility were associated with a slower gait (p < 0.05). This study identified a six-component, MS-specific gait model, demonstrating that PwMS, particularly fallers, exhibit deficits in pace and asymmetry. Findings may help reduce redundancy when reporting gait outcomes and inform interventions targeting specific gait domains.

scholarly journals A principal component analysis approach to correcting the knee flexion axis during gait

2016 ◽  
Vol 49 (9) ◽  
pp. 1698-1704 ◽  
Author(s):  
Elisabeth Jensen ◽  
Vipul Lugade ◽  
Jeremy Crenshaw ◽  
Emily Miller ◽  
Kenton Kaufman
Keyword(s):  
Principal Component Analysis ◽  
Knee Flexion ◽  
Principal Component ◽  
Component Analysis ◽  
Analysis Approach

A German version of the Intermittent Claudication Questionnaire (ICQ): cultural adaptation and validation

VASA ◽  
2012 ◽  
Vol 41 (5) ◽  
pp. 333-342 ◽  
Author(s):  
Kirchberger ◽  
Finger ◽  
Müller-Bühl
Keyword(s):  
Principal Component Analysis ◽  
Intermittent Claudication ◽  
Completion Time ◽  
Short Form ◽  
Principal Component ◽  
Component Analysis ◽  
German Version ◽  
Average Completion Time ◽  
Sf 36 ◽  
Related Quality

Background: The Intermittent Claudication Questionnaire (ICQ) is a short questionnaire for the assessment of health-related quality of life (HRQOL) in patients with intermittent claudication (IC). The objective of this study was to translate the ICQ into German and to investigate the psychometric properties of the German ICQ version in patients with IC. Patients and methods: The original English version was translated using a forward-backward method. The resulting German version was reviewed by the author of the original version and an experienced clinician. Finally, it was tested for clarity with 5 German patients with IC. A sample of 81 patients were administered the German ICQ. The sample consisted of 58.0 % male patients with a median age of 71 years and a median IC duration of 36 months. Test of feasibility included completeness of questionnaires, completion time, and ratings of clarity, length and relevance. Reliability was assessed through a retest in 13 patients at 14 days, and analysis of Cronbach’s alpha for internal consistency. Construct validity was investigated using principal component analysis. Concurrent validity was assessed by correlating the ICQ scores with the Short Form 36 Health Survey (SF-36) as well as clinical measures. Results: The ICQ was completely filled in by 73 subjects (90.1 %) with an average completion time of 6.3 minutes. Cronbach’s alpha coefficient reached 0.75. Intra-class correlation for test-retest reliability was r = 0.88. Principal component analysis resulted in a 3 factor solution. The first factor explained 51.5 of the total variation and all items had loadings of at least 0.65 on it. The ICQ was significantly associated with the SF-36 and treadmill-walking distances whereas no association was found for resting ABPI. Conclusions: The German version of the ICQ demonstrated good feasibility, satisfactory reliability and good validity. Responsiveness should be investigated in further validation studies.

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