The evaluation of a vector coding technique to quantify intersegmental coupling within a limb over multiple cycles of walking is described. The angular position of the knee with respect to the hip during walking was examined based on relative motion plots generated from videographic data. Participants included one able-bodied individual and one with spinal cord injury; the latter was assessed before and after participating in an assisted walking program. Vector coding of the frame-to-frame changes in hip/knee relationship was used to quantify the relative motion plots. Vector analysis techniques were then used to produce a single value that represents the overall variability of the hip/knee coupling relationship over multiple cycles. Hypothetical and random data were also used to evaluate the coding algorithm. In addition, the technique was compared to an earlier method in the analysis of this same data. Vector coding provided an easily interpretable method of quantifying the intersegmental coupling relationships and assessing the degree of consistency in the intralimb coordination over multiple cycles. The measure is sensitive to change in the kinematic variables and appears to have good validity. In addition, this technique has advantages over prior techniques as it allows simultaneous comparison of multiple cycles, calculations are performed quickly, and the algorithm is easy to program.
Dejan Tepavac and Edelle Carmen Field-Fote
Emmie Hsu, Steve Bardfield, Bryant J. Cratty and Alan Garfinkel
This pilot study was conducted to test the usefulness of angle-angle diagrams and phase plane plots obtained through high-speed cinematographical methods for making graded assessments of associated movements in children. Kinematic data at the shoulder, elbow, and ankle joints of normal and motorically awkward children (5-7 years old) were obtained from digitized films of normal and heel walking trials on a motor driven treadmill. A computer program was developed to smooth, calculate, differentiate, and plot data. Angle-angle diagrams depicting simultaneous joint angular displacements of (a) shoulder versus ankle and (b) elbow versus ankle revealed graded differences in decoupling of joint motion, limb excursions, and joint range-of-motion changes between the 5-year-old, 7-year-old awkward, and 7-year-old normal subject. Phase planes of the shoulder, elbow, and ankle joint were obtained by plotting joint angular displacement against joint angular velocity. Differences in size, shape, and looping behavior showed the quantity of change and whether the changes were gradual or sudden. This noninvasive methodology and eventual standardization of angle-angle diagrams and phase planes could prove to be useful in providing more precise diagnoses of associated movements and other subtle movement disorders.
Yumeng Li, Rumit S. Kakar, Marika A. Walker, Yang-Chieh Fu, Timothy S. Oswald, Cathleen N. Brown and Kathy J. Simpson
the vector coding method could quantify the spatial coordination. 18 – 20 The vector coding method calculates the angle of the vector between adjacent data points in time on the angle-angle diagram, thus supplying spatial coordination information as well as movement dominancy of 1 segment over the
Wataru Kawakami, Makoto Takahashi, Yoshitaka Iwamoto and Koichi Shinakoda
abnormal musculoskeletal conditions. Recently, vector-coding technique, which solves these issues, has been used to evaluate coupling motion. This technique can be applied to an angle–angle diagram to quantify the movement coordination between 2 adjacent segments over time. 25 Moreover, a modified vector
Behrouz Abdoli, James Hardy, Javad F. Riyahi and Alireza Farsi
, Macleod, Sanders, & Coleman, 2003 ; Mullineaux & Uhl, 2010 ; Robins, Wheat, Irwin, & Bartlett, 2006 ). Therefore, the present study examined elbow and wrist movements as well as their angle-angle diagrams to provide kinematic data. Mullineaux, Bartlett, and Bennett ( 2001 ) modified the NoRMS based
Hai-Jung Steffi Shih, Danielle N. Jarvis, Pamela Mikkelsen and Kornelia Kulig
, given ground contact time was similar between groups (Figure 2 A). Vector coding was performed using a modified method described by Needham et al 12 and Miller et al. 11 Instead of angle–angle diagrams, force–force diagrams were constructed with the right vGRF ( F r ) on the horizontal axis and the