High impact loading activities such as jumping, performed during childhood is
advocated as one preventive method for increasing peak bone mass. Thus, we conducted a
randomized intervention to examine the effect of high impact loading on bone mass in 34
pre-pubescent boys and girl over a seven month period. Participants meeting all inclusion
criteria were randomized into either a jumping (n=18) or stretching group (n=16), both of
which exercised three times per week for 15 minutes. The jumping group completed 100
jumps off 24-inch boxes each session, while the stretching group performed low impact
flexibility exercises. Attrition was 85% (6 drop outs), with an overall attendance rate of
95%. Bone area and bone mineral content (BMC) was assessed using dual energy x-ray
absorptiometery (Ho logic QDR 1000/W) for the left hip (femoral neck, greater trochanter,
total hip), and lumbar spine (L[subscript 2-4]). Other measures were body composition (Lang skinfold
calipers); physical activity (self-report questionnaire); and calcium intake (food survey).
All measurements were assessed at baseline and 7 months. Significance is denoted as p<.05. Analysis of variance (ANOVA) revealed no baseline difference between groups for
age, height, weight, body fat, physical activity, or calcium intake (p>.05); however,
gender differences were found for FN BMC at baseline (p<.05). Repeated measures
ANOVA identified significant group differences for FN BMC (p=.015), with a trend for
significance for FN area (p=.055). No significant differences in BMC or bone area
were found at all other skeletal sites (p>.05). No group by gender interactions were found
at baseline or at the completion of the seven month intervention. No significant differences between groups were identified for body composition, physical activity, or calcium intake
in repeated measures ANOVA analyses (p>.05). In conclusion, 100 jumps performed 3
times per week at approximately 8x body weight were sufficient to stimulate an osteogenic
response at the femoral neck in pre-pubescent boys and girls. Implementing jumping
exercises into regular physical activity programs during pre-pubescent growing years may
increase peak bone mass and potentially reduce the onset of osteoporosis. / Graduation date: 1999
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/34070 |
| Date | 22 July 1998 |
| Creators | Fuchs, Robyn K. |
| Contributors | Snow, Christine |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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