Humeral torque in professional baseball pitchers

BACKGROUND: Spontaneous fracture of the humeral shaft in throwers is a rare but well-known phenomenon. Although it has been hypothesized that the biomechanics of the throw cause such fractures, it is not clear how or when the fractures occur in the pitching motion. METHODS: The torque acting about the long axis of the humerus was calculated in 25 professional baseball pitchers throwing in game situations. RESULTS: Peak humeral axial torque reached a mean value of 92 +/- 16 Nm near the time of maximum shoulder external rotation at the end of the cocking phase. This torque tended to externally rotate the distal end of the humerus relative to its proximal end. The direction of the torque was consistent with the external rotation spiral fractures of the humerus noted to occur in throwers. The magnitude of the peak humeral torque averaged 48% of the theoretical torsional strength of the humerus, suggesting that repetitive stress plays a role in humeral shaft fractures. CONCLUSIONS: Fractures are most likely to occur near the time of maximum shoulder external rotation when humeral torque peaks. Pitchers whose elbows were more extended at stride foot contact tended to have lower peak humeral torques.     

Upper-limb bone mineral density of female collegiate gymnasts versus controls

PURPOSE: We examined bilateral bone mineral density (BMD) in the arms of female college gymnasts to assess the relative contribution of high-impact loading forces versus daily activities on bone plasticity. METHODS: Twenty-five female collegiate gymnasts and 25 controls were studied. BMD of the lumbar spine, proximal femur, and whole body were assessed via dual energy x-ray absorptiometry. Upper-limb BMD was determined by custom analyses of the whole-body scans to examine arms individually. RESULTS: BMD of gymnasts was significantly (P < 0.0001) greater than controls at all sites. Whole-body BMD was 8% higher in gymnasts (1.270 +/- 0.078 vs 1.175 +/- 0.073 g x cm(-2)), with 18-19% differences in the lumbar spine (1.427 +/- 0.144 vs 1.212 +/- 0.106 g x cm(-2), right proximal femur (1.298 +/- 0.101 vs 1.100 +/- 0.129 g x cm(-2)), and left proximal femur (1.293 +/- 0.111 vs 1.104 +/- 0.133 g x cm(-2)). Arm BMD was 17% greater in gymnasts, with higher values in both dominant (1.013 + 0.067 vs 0.875 + 0.066 g x cm(-2)) and nondominant (1.002 + 0.060 vs 0.849 + 0.062 g x cm(-2)) arms. Intragroup comparisons revealed a significantly (P < 0.0001) greater BMD in the dominant arm of the controls but no side-to-side difference in the arms of the gymnasts. CONCLUSIONS: Upper-limb BMD followed use patterns in both gymnasts and controls, demonstrating that the forces imposed on the arms with gymnastics training enhanced BMD and resulted in no bilateral differences. These findings illustrate the association between gymnastics training and increased BMD throughout the body, suggesting that the high BMD values observed in gymnasts are due primarily to the activity itself rather than selection bias.     

Bone density in female elite gymnasts: impact of muscle strength and sex hormones.

PURPOSE: The aim of this study was to investigate BMD in Danish female elite gymnasts and the relationships to maximal muscle strength, sex hormone concentrations, and menstrual status. METHODS: Six artistic gymnasts, five rhythmic gymnasts, and six controls aged 15-20 yr served as subjects. BMD (g x cm(-2)) of lumbar spine, proximal femur, distal radius, and whole body were measured by dual-energy x-ray absorptiometry (DXA) scanning. Maximal muscle strength (Nm) was measured in isokinetic trunk extension, trunk flexion, and knee extension. Serum concentrations of estrogen and progesterone in follicular and luteal phases were evaluated. RESULTS: Three out of six artistic gymnasts had amenorrhea, and two artistic and one rhythmic gymnast experienced oligomenorrhea. BMD in artistic gymnasts was greater than controls (24-45%, P < 0.05) in all sites except whole body. BMD in rhythmic gymnasts was greater than controls (4-26%, P < 0.05) in all sites except distal radius. In gymnasts, BMD correlated to both maximal muscle strength (0.60 < r < 0.85, P < 0.05) and serum progesterone (0.65 < r < 0.75, P < 0.05). CONCLUSION: In spite of oligomenorrhea or amenorrhea, it is possible for female gymnasts to maintain a high BMD in both the axial (L2-L4) and appendicular skeleton. The correlations between BMD and maximal muscle strength and progesterone concentration in gymnasts may indicate that within the same athletic group, progesterone concentration has a permissive role in bone formation, thus affecting the positive impact of muscle strength.     

Skull bone mass deficit in prepubertal highly-trained gymnast girls.

It is known that impact loading sport can increase the bone mineral density in the stressed sites of the skeleton in athletes. However, non weight-bearing sites are seldom studied in healthy young girl athletes. In order to study the effects of a long term intensive training on the non-stressed region of the skeleton (skull), we investigated both highly-trained girl athletes, involved in sports requiring or not significant impact loading on the skeleton and a girl control group. Bone mineral content (BMC) and density (BMD) were measured in the whole body, at lumbar spine, femoral neck, trochanter, Ward's triangle, radius, head and ribs, in 60 prepubertal girls including 12 swimmers, 32 gymnasts and 16 controls. Measurements were made by DXA. There were no statistical differences between the groups as regards age, height, body weight, body mass index, lean tissue mass and dietary calcium intake. Mean BMD in gymnasts was statistically higher than in other groups for radius (p < 0.001), femoral neck (p < 0.05) and Ward's triangle (p < 0.05) while there was no difference between swimmers and controls. Head BMC was significantly lower in gymnasts compared to other groups (241.9+/-41 g vs. 285.8+/-34.7 g and 291.1+/-50.2 g respectively in swimmers and controls, p < 0.001). The same observation was made for head BMD (p < 0.01). When body weight was used as a covariant, the contribution of the head BMC to the whole body was significantly lower (p < 0.001) in gymnasts (24.97%) than in swimmers (27.88%) and controls (27.77%). When compared between groups, the slopes of the regressions for head/whole body BMC or BMD were significantly lower in gymnasts (p < 0.05) than in other groups. These data suggest that in prepubertal children the increased bone density induced by gymnastic training in the stressed sites of the body could be related to a decreased skull bone mass.     

Bone mineral content of cyclically menstruating female resistance and endurance trained athletes

The bone mineral content (BMC) at four sites on the axial and appendicular skeleton was compared among four groups of young adult (age = 17-38 yr) cyclically menstruating athletes (N = 40) who regularly performed either weightlifting resistance exercise (body builders) or nonresistance endurance exercise (runners, swimmers) and an inactive group of females (N = 18) of about equal age. Forearm BMC was measured using single photon absorptiometry at proximal (shaft) and distal sites on the radius. Dual photon absorptiometry was used to measure BMC at the lumbar vertebrae (L2-4) and femur at the femoral neck, Ward's triangle, and greater trochanter. Fat-free body mass (FFBM) was estimated from densitometry. Body builders had greater BMC than swimmers, collegiate runners, recreational runners, and controls. Mean differences in BMC among runners, swimmers, and controls were not significant (P less than or equal to 0.05). FFBM was correlated significantly with BMC (r = 0.35-0.56) at each site in the combined group of athletes (N = 39), whereas total body weight and BMC were correlated significantly at the distal radius site (r = 0.38) only. The results suggest that weight training may provide a better stimulus for increasing BMC than run and swim training.     

Humeral cortical and trabecular changes in the throwing athlete: a quantitative computed tomography study of male college baseball players

PURPOSE: To examine bone adaptation to the mechanical loading of baseball using quantitative computed tomography. METHODS: Quantitative computed tomography was performed on both throwing and nonthrowing humeri of 8 male college baseball players. Quantitative computed tomography geometric variables and volumetric cortical density were measured at each of 5 sites, located at 15%, 25%, 35%, 50%, and 75% of humeral length from distal to proximal. Volumetric trabecular density was measured at the most distal site only. RESULTS: Significant side-to-side differences in favor of the throwing arm were found at all sites for total cross-sectional bone area (8%-17%, P < 0.01), cortical bone area (17%-29%, P < 0.01), and cortical bone thickness (18%-31%, P < 0.05). There were no important differences seen for cortical density; in contrast, trabecular density was significantly different in favor of the throwing arm at the one site measured (38%, P < 0.05). CONCLUSION: The dominant humerus of baseball players adapts via increases in cortical size and trabecular density.     

Nutrition of premenarcheal athletes: relation with the lipid and apolipoprotein profiles

The lipid and apolipoprotein profiles in plasma and the nutritional intake were investigated in 25 female elite gymnasts, 23 recreational gymnasts, 21 girl swimmers, and 16 controls. The girls were matched for sexual development, assessed by means of breast development. The age of the girls varied from 10.0 to 15.0 years. The recreational gymnasts and the girl swimmers had the highest levels of HDL-C, while those of the elite gymnasts and the controls were equally low (P less than or equal to 0.05). The same trend was seen in the case of the HDL-C/TC, HDL-C/LDL-C, and HDL-C/apo A-I ratios (P less than or equal to 0.05). The swimmers and the controls had similar high levels of apo A-I, and the swimmers also had a low apo B level. The differences with the elite group reached statistical significance (P less than or equal to 0.05). The recreational gymnasts had a lower level of apo E than the elite gymnasts and the swimmers had (P less than or equal to 0.05). The composition of the diet, expressed in energy %, was similar for all groups. The recreational gymnasts had a higher P/S ratio than the controls. It is concluded that the differences in lipid and apolipoprotein profiles found between young, female athletes and controls are not associated with differences in dietary intake and may be due to differences in physical activity. Also, genetic factors may have contributed to the variation found in the mentioned profiles. Yet, in this pediatric population, the nutritional intake played a small but significant role relative to the plasma lipids and apolipoproteins.     

Olecranon stress fracture in a weight lifter: a case report

Stress fractures have been reported in the upper limb of sportspeople involved in upper limb dominated events. Olecranon stress fractures have been cited in baseball pitchers, javelin throwers, and gymnasts. The unusual case of a stress fracture of the olecranon in a young weight lifter is reported here. The minimally displaced stress fracture was treated with tension band and two Kirschner wires. The fracture healed in four months and the patient returned to light sports activity after six months.     

Spondylolysis as a cause of low back pain in swimmers

Low back pain (LBP) has recently become a common complaint in swimmers. The differential diagnosis of LBP in swimmers includes muscle and ligament sprains, Scheuerman disease, herniated disc, facet joint injury, tumors, infections, and spondylolysis. Although spondylolysis or listhesis is a frequent injury in the athlete, mainly in weightlifters, wrestlers, gymnasts, divers and ballet dancers, it is infrequently reported in swimmers. We have recently encountered four adolescent elite swimmers who complained of low back pain and were diagnosed as having spondylolysis. Three of the patients were either breast-strokers or butterfly swimmers. Plain radiography demonstrated the lesion in two patients. Increased uptake in bone scan was noted in all patients. CT was performed only in two patients and revealed the lesion in both. One patient was diagnosed within two weeks, and the diagnosis in the others was deferred for 2-7 months. The patients were treated successfully by reducing the intensity of their training program and the use of a corset for at least three months. Repeated hyperextension is one of the mechanisms for spondylolysis in athletes as is the case in breast-strokers and butterfly style swimmers. LBP in swimmers should raise the suspicion of spondylolysis. Plain radiography and bone scan should be performed followed by SPEC views, CT, or MRI as indicated. If the case is of acute onset as verified by bone scan, a Boston or similar brace should be used for 3 to 6 months in conjunction with activity modification and optional physical therapy. Multidisciplinary awareness of low back pain in swimmers, which includes trainers, sport medicine physicians, and physical therapists, should lead to early diagnosis and appropriate treatment.     

Proximal humeral coordinate systems can predict humerothoracic and glenohumeral kinematics of a full bone system

BackgroundClinical imaging often excludes the distal humerus, confounding definition of common whole-bone coordinate systems. While proximal anatomy coordinate systems exist, no simple method transforms them to whole-bone systems. Their influence on humeral kinematics is unknown.Research questionHow do humeral kinematics vary based on proximal and whole-bone coordinate systems, and can average rotation matrices accurately convert kinematics between them?MethodsThree proximal coordinate systems were defined by the lesser and greater tuberosities (LT, GT), Crest of the greater tuberosity, and humeral shaft. Average rotation matrices derived from anatomic landmarks on cadaver humeri were generated between the proximal and whole-bone coordinate systems. Absolute angle of rotation was used to determine if anatomical variability within the cadaver population influenced the matrices. The matrices were applied to humerothoracic and glenohumeral motion (collected previously) and analyzed using the proximal coordinate systems, then expressed in the whole-bone system. RMSE was used to compare kinematics from the proximal and whole-bone systems.ResultsA single average rotation matrix between a given proximal and whole-bone coordinate system achieved consistent error, regardless of landmarks. Elevation and plane of elevation had <2° mean error when proximal coordinate systems were transformed to whole-bone kinematics. Axial rotation had a mean 7° error, primarily due to variable humeral head retroversion. Absolute angles of rotation did not statistically differ between subgroups. The average rotation matrices were independent of sex, side, and motion.SignificanceProximal humerus coordinate systems can accurately predict whole-bone kinematics, with most error concentrated in axial rotation due to anatomic twist along the bone. These results enhance interpretability and reproducibility in expressing humerothoracic and glenohumeral motion data between laboratories by providing a simple means to convert data between common coordinate systems. This is necessitated by the lack of distal humerus anatomy present in most clinical imaging.     

Growth and pubertal development of young female gymnasts and swimmers: a correlation with parental data

Whereas intensive and regular physical training is known to alter female reproductive function, its potential role in growth is still controversial. At the beginning of a longitudinal growth study of young elite female gymnasts (n = 34, 15-25 h/wk training) and moderately trained swimmers (n = 19, 5-15 h/wk), patterns of recalled parental growth and pubertal maturation were compared with those of parents of 25 sedentary school girls. These data were also correlated to the height, weight, pubertal development as well as adult height prognosis of their daughters. Bone age was estimated using the methods of Greulich-Pyle and Tanner (RUS score) and adult height prognosis using the methods of Bayley-Pinneau (BP), Roche-Wainer-Thissen (RWT), and Tanner et al. (TW2). Parents of gymnasts were significantly lighter (fathers: P = 0.027; mothers: P = 0.038) and shorter (fathers: P = 0.034; mothers: P less than 0.001) than those of swimmers and controls. Consequently, target heights of gymnasts were also significantly shorter (P less than 0.001). Recalled menarche occurred significantly later (P = 0.030) in mothers of gymnasts who, in turn, grow much alike their mothers. At the first visit, the gymnasts were shorter and lighter for age than swimmers and controls. Their bone age (11.0 +/- 1.3 years, mean +/- SD) was retarded (P less than 0.001) when compared with chronological age (12.6 +/- 1.2 years). Adult height prognosis was lower for gymnasts than for other girls (BP: P less than 0.001; RWT: P = 0.023, TW2: P less than 0.001), but adequate for target height range.(ABSTRACT TRUNCATED AT 250 WORDS)     

手术治疗肱骨近端骨折83例临床分析

目的探讨肱骨近端骨折的手术治疗方法。方法回顾性分析比较肱骨近端锁定钢板与三叶钢板治疗肱骨近端骨折的效果。结果锁定钢板治疗组的疗效与三叶钢板治疗组,在满意度、并发症情况、手术时间和输血量等方面均存在显著性差异（P〈0.05）。结论肱骨近端锁定刚板可使骨折部得到复位及稳定的固定,对骨和软组织血供影响小,可使患肩关节早期安全的活动,避免关节僵硬,是治疗肱骨近端骨折首选的治疗方法。     

Differences in sole arch indices in various sports

Background: There are controversial data about the relation between foot morphology and athletic injuries of the lower extremity. Studies in soldiers have shown some relationship, whereas those involving athletes have not shown any significant relationship. The reason for these differences is not clear.

Objective: To determine the effect of various sports on sole arch indices (AIs).

Method: A total of 116 elite male athletes (24 soccer players, 23 wrestlers, 19 weightlifters, 30 handball players, and 20 gymnasts) and 30 non-athletic men were included in this cross sectional study. Images of both soles were taken in a podoscope and transferred to a computer using a digital still camera. AIs were calculated from the stored images.

Results: The AI of the right sole of the gymnasts was significantly lower than that of the soccer players, wrestlers, and non-athletic controls (p<0.01). The AI of the right sole of the wrestlers was significantly higher than that of the soccer players, handball players, weightlifters, gymnasts, and non-athletic controls (p<0.03). The AI of the left sole of the gymnasts was significantly lower than that of the wrestlers and non-athletic controls (p<0.001). The AI of the left sole of the wrestlers was significantly higher than that of the soccer players, handball players, and gymnasts (p<0.007). The AI of both soles in handball players was significantly lower than those of the non-athletic subjects (p = 0.049). The correlation between the AI of the left and right foot was poor in the soccer players, handball players, and wrestlers (r = 0.31, 0.69, and 0.56 respectively), but was high in the gymnasts, weightlifters, and non-athletic controls (r = 0.96, 0.88, and 0.80 respectively).

Conclusion: The AIs of the gymnasts and wrestlers were significantly different from those of other sportsmen studied, and those of the gymnasts and handball players were significantly different from those of non-athletic controls.

     

Artistic versus rhythmic gymnastics: effects on bone and muscle mass in young girls

We compared 35 prepubertal girls, 9 artistic gymnasts and 13 rhythmic gymnasts with 13 nonphysically active controls to study the effect of gymnastics on bone and muscle mass. Lean mass, bone mineral content and areal density were measured by dual energy X-ray absorptiometry, and physical fitness was also assessed. The artistic gymnasts showed a delay in pubertal development compared to the other groups (p<0.05). The artistic gymnasts had a 16 and 17 % higher aerobic power and anaerobic capacity, while the rhythmic group had a 14 % higher anaerobic capacity than the controls, respectively (all p<0.05). The artistic gymnasts had higher lean mass (p<0.05) in the whole body and the extremities than both the rhythmic gymnasts and the controls. Body fat mass was 87.5 and 61.5 % higher in the controls than in the artistic and the rhythmic gymnasts (p<0.05). The upper extremity BMD was higher (p<0.05) in the artistic group compared to the other groups. Lean mass strongly correlated with bone mineral content (r=0.84, p<0.001), and multiple regression analysis showed that total lean mass explained 64 % of the variability in whole body bone mineral content, but only 20 % in whole body bone mineral density. Therefore, recreational artistic gymnastic participation is associated with delayed pubertal development, enhanced physical fitness, muscle mass, and bone density in prepubertal girls, eliciting a higher osteogenic stimulus than rhythmic gymnastic.     

Eating problems and calorie intake levels in Swiss adolescent athletes

The purpose of this study was to investigate the incidence of eating disorders (ED), calorie intake levels and body fat measures in Swiss female athletes. Thirty athletic and 34 non-athletic adolescent Swiss females were assessed for tendencies toward eating disorders and weight preoccupation using the Eating Disorders Inventory (EDI). Calorie intakes were calculated from 7-day intake records. Body compositions were determined using skin-fold measures. The athletes were divided into two groups: Those whose activities emphasize leanness (12 gymnasts, means age = 12.5 +/- 1.1 yrs), and those whose activities do not emphasize leanness (18 swimmers, mean age = 12.8 +/- 0.9 yrs). The non-athletic school-girls (mean age = 13.4 +/- 1.2 yrs) served as controls. ANOVA indicated that the gymnasts had lower body fat levels (p less than 0.01) and consumed fewer total calories (p less than 0.05) than swimmers or controls, but all groups consumed similar calories per kg/body weight. Chi square analysis indicated that similar numbers of swimmers (11%), gymnasts (1%) and controls (6%) were exceptionally preoccupied with weight (p greater than 0.05). However, more swimmers (38%) scored high on the body dissatisfaction subscale of the EDI than the gymnasts (1%) or control (9%) (p less than 0.01). In fact, more swimmers scored high on 3 subscales of the EDI compared to the other groups (p less than 0.05). It appears that disturbances in eating behaviors are not limited to sports that emphasize leanness.     

Premenarcheal gymnasts possess higher bone mineral density than controls

PURPOSE: The purpose of this study was to examine bone mineral density (BMD), body composition, dietary intake, physical activity, and energy expenditure (EE) in premenarcheal gymnasts (N = 16; age = 10.5 +/- 1.5 yr) in comparison to age- (+/- 0.35 yr), height- (+/- 2.6 cm), and weight- (+/- 1.5 kg) matched controls (N = 16; age = 10.5 +/- 1.3 yr). It was hypothesized that premenarcheal gymnasts would have higher BMD, fat-free soft tissue (FFST) mass, physical activity, and EE, but lower fat mass, percent body fat, and dietary intake than controls. METHODS: Dual energy x-ray absorptiometry was used to measure whole body, femur, and lumbar spine (L1-4) BMD, FFST, and fat mass. Three-day diet records were used to estimate mean daily dietary energy, macronutrient, and calcium intakes. Physical activity and EE were estimated by the Seven-Day Physical Activity Recall. RESULTS: The BMD means of the gymnasts were significantly higher (P < 0.05) than controls at all sites, except whole body, as were lumbar spine and femoral neck bone mineral apparent densities, despite lower protein intake expressed per kg FFST mass. Fat mass was significantly lower in gymnasts versus controls (P < 0.01) as was percent body fat (P < 0.001). Very hard physical activity during weekdays (P < 0.0001) and estimated EE (P < 0.01) were significantly higher in gymnasts compared with controls. CONCLUSION: Premenarcheal gymnasts have higher BMD than age-, height-, and weight-matched controls.     

Activité physique et remodelage osseux : étude chez une population de jeunes gymnastes

Aims – Intensive exercise is known to improve the bone mass acquisition. One of the main explanations consists in the mechanical strains exerted on the skeleton. Little is known about the effects of physical exercise on the bone remodelling process.Methods and results – The bone remodelling rate evaluated in a group of young female (24 gymnasts and 21 controls), using a bone resorption marker, the CrossLaps peptides CTx. We measured in our subjects the bone mineral density at the whole body and at six regional sites. The bone density was statistically higher in the gymnasts compared to the controls at all the specific sites. The CTx level corrected by urinary creatinine was significantly higher in the gymnasts, reflecting a faster bone remodelling rate.Conclusion – Intensive physical activity could improve the bone mineral acquisition probably by a stimulation of the bone remodelling activity.     

锁定钢板加同种异体骨移植治疗老年肱骨近端骨折

目的总结和评价应用肱骨近端锁定钢板（locking proximal humeral plate,LPHP）加同种异体骨移植治疗老年肱骨近端骨折的临床疗效。方法应用LPHP加同种异体骨移植治疗28例老年肱骨近端骨折患者,年龄59～78岁,平均65岁。根据肱骨近端骨折的Neer分型,其中二部分骨折4例,三部分骨折16例,四部分骨折8例,均有不同程度骨质疏松。结果本组28例患者获得随访11～18个月,平均12个月;28例骨折全部愈合,按Neer评分标准评分,优14例,良10例,可4例,差0例;优良率85.7%。结论LPHP加同种异体骨移植治疗老年肱骨近端骨折,疗效满意。     

人工肱骨头置换术治疗老年肱骨近端复杂性骨折

目的 探讨人工肱骨头置换术治疗老年肱骨近端复杂性骨折的适应证、手术要点和疗效.方法 2000-2006年共行人工肱骨头置换手术治疗老年肱骨近端复杂性骨折23例,骨水泥固定,有计划的康复训练. 结果 术后19例获得随访,平均1.8年,未发生切口感染、神经损伤、假体周围骨折,1例有半脱位.采用Neer评分系统评定人工关节功能,本组平均82.1分,其中80～89分(满意)17例,70～79分(不满意)2例,满意率为89%,无翻修病例. 结论 人工肱骨头置换术在严格掌握适应证、重视肩袖和关节稳定结构的重建、有计划的康复训练下,是治疗老年性肱骨近端复杂骨折的一种良好方法.     

Aerobic workout and bone mass in females

This cross-sectional study aimed to investigate bone mass in females participating in aerobic workout. Twenty-three females (age 24.1±2.7 years), participating in aerobic workout for about 3 hours/week, were compared with 23 age-, weight- and height-matched non-active females. Areal bone mineral density (BMD) was measured in total body, head, whole dominant humerus, lumbar spine, right femoral neck, Ward's triangle, trochanter femoris, in specific sites in right femur diaphysis, distal femur, proximal tibia and tibial diaphysis, and bone mineral content (BMC) was measured in the whole dominant arm and right leg, using dual energy X-ray absorptiometry. The aerobic workout group had significantly ( P <0.05–0.01) higher BMD in total body (3.7%), lumbar spine (7.8%), femoral neck (11.6%), Ward's triangle (11.7%), trochanter femoris (9.6%), proximal tibia (6.8%) and tibia diaphysis (5.9%) compared to the non-active controls. There were no differences between the groups concerning BMD of the whole dominant humerus, femoral diaphysis, distal femur and BMC and lean mass of the whole dominant arm and right leg. Leaness of the whole dominant arm and leg was correlated to BMC of the whole dominant arm and right leg in both groups. In young females, aerobic workout containing alternating high and low impact movements for the lower body is associated with a higher bone mass in clinically important sites like the lumbar spine and hip, but muscle strengthening exercises like push-ups and soft-glove boxing are not associated with a higher bone mass in the dominant humerus. It appears that there is a skeletal adaptation to the loads of the activity.