Hip and Knee Angle while Walking

Description

Hip and knee angle (in degrees) through a 20 point movement cycle for 39 boys.

Usage

gait

Format

A 3-dimensional array with dimensions c(20, 39, 2) giving the "Hip Angle" and "Knee Angle" (in degrees) for 39 repetitions of a 20 point gait cycle (over standardized gait times).

Details

The named components of dimnames(gait) are as follows:

Time

seq(from = 0.025, to = 0.975, by = 0.05)

Subject

"boy1", "boy2", ..., "boy39"

Variable

"Hip Angle" and "Knee Angle"

Note

This is the version of the data as in the fda package and corresponding textbooks, but with named dimensions. One record appears to be duplicated from the original paper, Olshen et al. (1989), which analyses a sample of 38 boys. The gait dataset has 39 boys but boy19 and boy26 have identical measurements.

Source

In the FDA book (2006), p.8, “The Motion Analysis Laboratory at Children's Hospital, San Diego, collected these data”.

References

Olshen, R. A., Biden, E. N., Wyatt, M. P., and Sutherland, D. (1989) Gait Analysis and the Bootstrap. Annals of Statistics 17, 4, 1419–1440. doi:10.1214/AOS/1176347372

Ramsay, J. O., and Silverman, B. W. (2006) Functional Data Analysis, 2nd ed., New York: Springer.

Ramsay, J. (2023) fda: Functional Data Analysis. R package version 6.1.4, https://CRAN.R-project.org/package=fda.

Examples

plot(gait[, 1, ], type = "b",
     xlim = range(gait[,,1]), ylim = range(gait[,,2]), 
     xlab = "Hip Angle", ylab = "Knee Angle", main = "'gait' data : Boy 1")
mtext("all other boys", col = "thistle"); grid()
matlines(gait[, -1, 1], gait[, -1, 2], type = "l", lty = 1, col = adjustcolor("thistle", 1/3))

## The data array, two matrices :
op <- options(width = 128) # on a wide console
aperm(gait, c(2:1, 3))
options(op)