Biomedical subjects

O Diallo

Publications and source records attributed to O Diallo.

5 recordsLinked to original sources

PubMed2001

Effects of plyometric training followed by a reduced training programme on physical performance in prepubescent soccer players.

BACKGROUND: In adult population, stretch-shortening cycle exercise (plyometric exercise) is often used to improve leg muscle power and vertical jump performance. In children, limited information regarding this type of exercise is available. The purpose of this study was to examine the effectiveness of plyometric training and maintenance training on physical performances in prepubescent soccer players. METHODS: Twenty boys aged 12-13 years was divided in two groups (10 in each): jump group (JG) and control group (CG). JG trained 3 days/week during 10 weeks, and performed various plyometric exercises including jumping, hurdling and skipping. The subsequent reduced training period lasted 8 weeks. However, all subjects continued their soccer training. Maximal cycling power (Pmax) was calculated using a force-velocity cycling test. Jumping power was assessed by using the following tests: countermovement jump (CMJ), squat jump (SJ), drop jump (DJ), multiple 5 bounds (MB5) and repeated rebound jump for 15 seconds (RRJ15). Running velocities included: 20, 30 and 40 m (V20, V30, V40 m). Body fat percentage (BF percent) and lean leg volume were estimated by anthropometry. RESULTS: Before training, except for BF percent, all baseline anthropometric characteristics were similar between JG and CG. After the training programme, Pmax (p<0.01), CMJ (p<0.01), SJ (p<0.05), MB5 (p<0.01), RRJ15 (p<0.01) and V20 m (p<0.05), performances increased in the JG. During this period no significant performance increase was obtained in the CG. After the 8-week of reduced training, except Pmax (p<0.05) for CG, any increase was observed in both groups. CONCLUSIONS: These results demonstrate that short-term plyometric training programmes increase athletic performances in prepubescent boys. These improvements were maintained after a period of reduced training.

Adolescent↗

PubMed2001

[Gastric pneumatosis as a sign of duodenal stenosis in a child with Down syndrome].

A case of gastric pneumatosis is described in a 6 month old girl with Down syndrome. Plain abdominal radiographs showed a radiolucent rim within the gastric wall and a dilated stomach. Ultrasonography showed diffuse echoic streaks of air in the gastric wall, pneumobilia and gastroduodenal dilatation. Upper GI series showed duodenal stenosis. Gastric pneumatosis (air within the gastric wall), is an unusual radiographic finding. It may be of mechanical or inflammatory origin or, in some rare cases, remain unexplained.

Constriction, Pathologic↗

PubMed2000

Dimensional changes cannot account for all differences in short-term cycling power during growth.

The purpose of this study was to determine to what extent anthropometric characteristics account for cycling peak power during growth. Five hundred and six male subjects aged 7.5-18 years performed three brief maximal sprints on a friction-loaded cycle ergometer. Cycling peak power (CPP) was calculated including the flywheel inertia of the device. Fat-free mass (FFM) and lean leg volume (LLV) were assessed by anthropometry. Anthropometric characteristics increased significantly during growth (p<0.001) but plateaued from about 16 years of age (p > 0.3). The same pattern was observed for CPP, while the time to reach CPP decreased during growth. CPP correlated as highly with LLV as with FFM and both parameters may therefore be interchanged. However, in non weight-bearing exercises, such as cycling, it seems more relevant to "normalise" leg power for LLV. Multiple stepwise regression, using an allometric model, showed that a large part of the variance of CPP was explained by LLV (88.2%, p<0.001). However, age and time to reach peak power also contributed significantly (approximately 3 %, p < 0.001). The prediction of CPP revealed that FFM and age contributed to 92.2% of the total variance of CPP. Because of its practicability, fat-free mass is particularly useful in prospective studies. Although the effects of dimensional changes in CPP during growth are obvious, undetermined qualitative changes of muscle function during maturation must be considered.

Adolescent↗

PubMed2000

Testing peak cycling performance: effects of braking force during growth.

The purpose of this study was to investigate the relationship between cycling peak power (CPP; flywheel inertia included) and the applied braking force (F(B)) on a friction-loaded cycle ergometer in male children, adolescents, and adults. A total of 520 male subjects aged 8-20 yr performed three brief maximal sprints against three F(B): 0.245, 0.491, and 0.736 N x kg(-1) body mass (BM) (corresponding applied loads: 25 [F(B)25], 50 [F(B)50], and 75 [F(B)75] g x kg(-1) BM). For each F(B), peak power (PP) was measured (PP25, PP50 and PP75). For each subject, the highest PP was defined as CPP. Results showed that PP was dependent on F(B). In young adults PP25 underestimated CPP by more than 10%, and consequently, F(B)25 seemed to be too low for this population. However, in children, PP75 underestimated CPP by about 20%. A F(B) of 0.736 N x kg(-1) BM was definitively too high for the pediatric population. Therefore, the optimal F(B), even corrected for BM, was lower in children than in adults. The influence of growth and maturation on the force-generating capacity of the leg muscles may explain this difference. In this study, however, it was shown that the difference between PP50 and CPP was independent of age for the whole population investigated. Consequently, when flywheel inertia is included, one cycling sprint with a F(B) of 0.495 N x kg(-1) BM (corresponding applied load: 50 g x kg(-1) BM) is a feasible method for testing both children, adolescents, or young adults.

Adolescent↗

PubMed1986

Evaluation of a new combined inactivated DPT-polio vaccine.

A new combined DPT-Poliovirus vaccine (DPTP) has been developed in France. It contains the DPT components mixed with poliovirus antigens, prepared by culture on vero cells on microcarriers, inactivated by formalin and formulated at a level of 40-8-32 D-antigen units for the type 1, 2 and 3 respectively. A clinical evaluation of this vaccine was conducted in Mali (West Africa) among 320 infants 3 to 24 months of age. The infants were randomly assigned to 3 groups. One group received 2 doses of DPTP, a second group 2 doses of DPT and poliovirus vaccine (IPV) given in two separate sites, the third group 2 doses of DPT and oral poliovirus vaccine (OPV). In each group the 2 doses were given 3 months a part. No severe adverse reactions were observed and no statistical difference was noticed between the three groups for minor side effects. A seroconversion rate of 100% was observed to poliovirus antigens in the groups who received IPV simultaneously or combined with DPT, as compared to 49 to 77% in the group who received OPV. A seroconversion rate of 100%, 100% and 92% was shown in the DPTP group respectively to diphtheria, tetanus and pertussis antigens. No statistical difference was recorded between the 3 groups in the serological response to DPT antigens. A follow-up could be performed in 74 children one year after primary vaccination and a dramatic response to a booster dose of DPTP was measured.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗