Cl. Zimmermann et al., EFFECTS OF STAIR-STEPPING EXERCISE DIRECTION AND CADENCE ON EMG ACTIVITY OF SELECTED LOWER-EXTREMITY MUSCLE GROUPS, The Journal of orthopaedic and sports physical therapy, 19(3), 1994, pp. 173-180
Step ergometry has become a popular treatment mode in cardiovascular f
itness and knee rehabilitation programs. The following study describes
the effects of forward stair stepping at 35 and 95 steps/minute and f
orward and retrograde stair stepping at 60 steps/minute on the mean el
ectromyographic (EMG) activity of the gluteus maximus, rectus femoris,
vastus medialis, semimembranosus/semitendinosus, and gastrocnemius mu
scles. Thirty-three subjects without prior lower extremity pathology p
articipated in the study. Analysis of variance was used to compare mea
n EMG activity during the knee extension phase of the different steppi
ng conditions. Significant differences (p < 0.05) in mean EMGs of glut
eus maximus, rectus femoris, vastus medialis, and gastrocnemius were n
oted across all cadences. The semimembranosus/semitendinosus EMG activ
ity displayed a single significant difference between the cadences of
35 and 95. The comparison between forward and retrograde stepping iden
tified only one significant difference in mean EMC (semimembranosus/se
mitendinosus). The effects of cadence on EMG activity should be consid
ered when developing conditioning or rehabilitation programs for the l
ower extremity. Faster cadences result in increased peak activity of s
horter duration for the gluteus maximus, quadriceps, and gastrocnemius
. There is no apparent difference in EMG activity of the hamstrings du
e to cadence. Also, noting the minimal activation that occurs, stair-s
tepping exercise would not be recommended for strengthening of the ham
strings musculature.