| 1. |
- Alfredson, Håkan, et al.
(författare)
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Bone mass in female volleyball players : a comparison of total and regional bone mass in female volleyball players and nonactive females
- 1997
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Ingår i: Calcified Tissue International. - : Springer. - 0171-967X .- 1432-0827. ; 60:4, s. 338-342
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this cross-sectional study was to evaluate bone mass in female athletes participating in an impact loading sport (volleyball), and especially to investigate whether any changes in bone mass might be related to the type and magnitude of weightbearing loading and muscle strength. The volleyball group consisted of 13 first division players (age 20.9 +/- 3.7 years) training for about 8 hours/week, and the reference group consisted of 13 nonactive females (age 25.0 +/- 2.4 years) not participating in any kind of regular or organized sport activity. The groups were matched according to weight and height. Areal bone mineral density (BMD) was measured in total body, head, lumbar spine, femoral neck, Ward's triangle, trochanter, the whole femur, and humerus using dual-energy-X-ray absorptiometry. Isokinetic concentric peak torque of the quadricep and hamstring muscles was measured using an isokinetic dynamometer. Compared with the controls, the volleyball players had a significantly (P < 0.05-0.01) higher BMD of the total body (6.1%), lumbar spine (13.2%), femoral neck (15.8%), Ward's triangle (17.9%), trochanter (18.8%), nondominant femur (8.2%), and humerus (dominant 9.5%, nondominant 10.0%), but not of the head and the dominant whole femur. The dominant humerus showed significantly higher BMD than the nondominant humerus in both the volleyball and nonactive group (P < 0.05). There was no significant difference in muscle strength of the thigh between the two groups. In the nonactive group, muscle strength in the quadriceps, and especially hamstrings, was correlated to BMD of the adjacent bones (whole femur, hip sites) and also to distant sites (humerus). However, in the volleyball group there were no correlations between muscle strength and BMD of the adjacent bones, but quadricep strength correlated to BMD of the humerus. These results clearly show that young female volleyball players have a high bone mass. The demonstrated high bone mass seems to be related to the type of loading subjected to each BMD site. Muscle strength of the thigh seems to have little impact on BMD in female volleyball players.
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| 2. |
- Alfredson, Håkan, et al.
(författare)
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Bone mass in the calcaneus after heavy loaded eccentric calf-muscle training in recreational athletes with chronic achilles tendinosis
- 1999
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Ingår i: Calcified Tissue International. - : Springer. - 0171-967X .- 1432-0827. ; 64:5, s. 450-455
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Tidskriftsartikel (refereegranskat)abstract
- In an ongoing prospective study of 14 recreational athletes (12 males and 2 females, mean age 44.2 +/- 7.1 years) with unilateral chronic Achilles tendinosis, we investigated the effect of treatment with heavy-loaded eccentric calf-muscle training. Pain during activity (recorded on a VAS scale) and isokinetic concentric and eccentric calf-muscle strength (peak torque at 90 degrees /second and 225 degrees /second) on the injured and noninjured side were evaluated. In this group of patients, we examined areal bone mineral density (BMD) of the calcaneus after 9 months (range 6-14 months) of training. BMD of the injured side (subjected to heavy-loaded eccentric training) was compared with BMD of the noninjured side. Before onset of heavy-loaded eccentric training, all patients had Achilles tendon pain which prohibited running activity, and significantly lower concentric and eccentric plantar flexion peak torque on the injured compared with the noninjured side. The training program consisted of 12 weeks of daily, heavy-loaded, eccentric calf-muscle training; thereafter the training was continued for 2-3 days/week. The clinical results were excellent-all 14 patients were back at their preinjury level with full running activity at the 3 month follow-up. The concentric and eccentric plantar flexion peak torque had increased significantly and did not significantly differ from the noninjured side at the 3 and 9 month follow-up. There were no significant side-to-side differences in BMD of the calcaneus. There was no significant relationship between BMD of the calcaneus and calf-muscle strength. As a comparison group, we used 10 recreational athletes (5 males and 5 females) mean age 40.9 years (range 26-55 years), who were selected for surgical treatment of chronic Achilles tendinosis localized at the 2-6 cm level. Their duration of symptoms and severity of disease were the same as in the experimental group. There were no significant side-to-side differences in BMD of the calcaneus preoperatively, but 12 months postoperatively BMD of the calcaneus was 16.4% lower at the injured side compared with the noninjured side. Heavy-loaded eccentric calf-muscle training resulted in a fast recovery in all patients, equaled the side-to-side differences in muscle strength, and was not associated with side-to-side differences in BMD of the calcaneus. In this group of middle-aged recreational athletes, BMD of the calcaneus was not related to calf-muscle strength.
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| 3. |
- Alfredson, Håkan, et al.
(författare)
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High thigh muscle strength but not bone mass in young horseback-riding females
- 1998
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Ingår i: Calcified Tissue International. - : Springer. - 0171-967X .- 1432-0827. ; 62:6, s. 497-501
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate whether the type of weight-bearing loading subjected to the skeleton during horseback-riding was associated with differences in bone mass and muscle strength of the thigh, we investigated bone mass and isokinetic muscle strength in 20 female horse riders (age 17.9 +/- 0.6 years) who were riding 7.0 +/- 3.4 hours/week, and 20 nonactive females (age 17.8 +/- 1.1 years). The groups were matched according to age, weight, and height. Areal bone mineral density was measured in total body, head, lumbar spine, right femoral neck, Ward's triangle, and trochanter, the whole dominant and nondominant humerus, and in specific sites in the right femur diaphysis, distal femur, proximal tibia, and tibia diaphysis using dual X-ray absorptiometry. Isokinetic concentric and eccentric peak torque of the quadricep and hamstring muscles were measured using an isokinetic dynamometer. There were no significant differences in bone mass between the horseback riders and nonactives at any site measured. The horse riders were significantly (P < 0.05-0.01) stronger in concentric hamstrings strength at 90 degrees/second and 225 degrees/second and in eccentric quadricep and hamstring strength at 90 degrees/second. Horseback riding in young females is associated with a high muscle strength of the thigh, but not with a high bone mass.
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| 4. |
- Alfredson, Håkan, et al.
(författare)
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Long-term loading and regional bone mass of the arm in female volleyball players
- 1998
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 0171-967X .- 1432-0827. ; 62:4, s. 303-308
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, we compared the bone mineral content (BMC) and bone mineral density (BMD) in the arms of 11 female volleyball players (mean age 22.0 +/- 2.6 years) training for about 8 hours/week, and 11 nonactive females aged 24.6 +/- 3.1 years (mean +/- SD) not participating in regular or organized sport activity. Using dual X-ray absorptiometry (DXA), BMC was measured in the proximal and distal humerus, and BMD in the distal radius. Isokinetic concentric peak torque (highest value attained during 5 or 10 repetitions) of the rotator muscles of the shoulder and flexor and extensor muscles of the elbow were measured using an isokinetic dynamometer. The volleyball players had significantly higher BMC (P < 0.05) at the proximal humerus of the dominant arm compared with the nonactive group, but there were no differences between the groups in BMC of the distal humerus and BMD of the distal radius. In the volleyball players, BMC was significantly higher at the proximal humerus, at the distal humerus, and at the distal radius in the dominant compared with the nondominant arm. In the nonactive group, there were no significant differences in BMC and BMD between the dominant and nondominant arm at any site measured. Except for shoulder internal rotation strength and elbow flexion strength at 90 degrees/second that was higher in the dominant arm in the volleyball players, there were no significant differences in muscle strength of the rotator muscles of the shoulder and flexor and extensor muscles of the elbow between the dominant and nondominant arm in the volleyball players and nonactive controls. In the volleyball players, but not in the nonactive controls, there were several significant relationships between shoulder and elbow strength and BMC at the distal humerus of the dominant and especially the nondominant arm. These results show that young female volleyball players have a higher bone mass in the proximal humerus, distal humerus, and distal radius in the dominant compared with the nondominant arm, and a higher bone mass in the proximal humerus compared with nonactive controls. Muscle strength of the rotator muscles of the shoulder is not related to the higher bone mass in the proximal humerus of the dominant arm. Theoretically, the observed differences in bone mass can be related to the type of loading the skeleton undergoes when playing volleyball.
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| 5. |
- Alfredson, Håkan, et al.
(författare)
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Prolonged progressive calcaneal bone loss despite early weightbearing rehabilitation in patients surgically treated for Achilles tendinosis
- 1998
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Ingår i: Calcified Tissue International. - : Springer. - 0171-967X .- 1432-0827. ; 62:2, s. 166-171
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Tidskriftsartikel (refereegranskat)abstract
- We prospectively evaluated areal bone mineral density (BMD) of the calcaneus and calf-muscle strength (concentric and eccentric plantar flexion peak torque in Nm) in 10 recreational athletes (5 males and 5 females), mean age 40.9 years (range 26-55), who were selected to undergo surgical treatment for chronic Achilles tendinosis localized at the 2-6 cm level. Surgery was followed by immobilization in a plaster cast for 2 weeks, followed by flexibility training and slowly progressing strength training and weight-bearing activity. One patient was excluded after week 0 because of a new injury. Seven patients were back to their preinjury activity at the 26-week control, and eight patients at the 52-week control postoperatively. BMD in the calcaneus and calf-muscle strength on the injured and noninjured side was measured preoperatively (week 0) and postoperatively (weeks 2, 6, 16, 26, and 52). There were no significant differences in BMD between the injured and noninjured side at weeks 0, 2, and 6, but at weeks 16, 26, and 52, BMD was significantly (P < 0.05) lower (11.5%, 18.4%, and 16.4%, respectively) in the calcaneus of the injured side. Concentric and eccentric plantar flexion strength were significantly lower on the injured side preoperatively. Eccentric, but not concentric plantar flexion strength had recovered compared with the noninjured side 1 year postoperatively. Calf-muscle strength was not related to bone mass in the calcaneus. As a comparison, we used a group of 11 recreational athletes (10 males and 1 female), with a mean age of 46.1 years (range 28.9-58.5) who had been surgically treated for chronic Achilles tendinosis at the 2-6 cm level 39.5 +/- 11.8 months ago. In this group, there was no significant difference in BMD of the calcaneus between the injured and noninjured side. It seems that there was a delayed and prolonged calcaneal bone loss despite early weightbearing loading in patients surgically treated for chronic Achilles tendinosis at the 2-6 cm level. Around that time, when the Achilles tendon had healed (4-6 months) and the athletes returned to their sports, the calcaneal bone had a relatively low BMD and might possibly be vulnerable to heavy loadings. There were no signs of recovery 1 year postoperatively, but in a comparison group there were no significant side-to-side differences 39.5 months postoperatively.
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| 6. |
- Alfredson, Håkan, et al.
(författare)
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Total and regional bone mass in female soccer players
- 1996
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Ingår i: Calcified Tissue International. - : Springer. - 0171-967X .- 1432-0827. ; 59:6, s. 438-442
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Tidskriftsartikel (refereegranskat)abstract
- This cross-sectional study investigated bone mass in female athletes participating in an impact-loading sport (soccer), and evaluated whether any changes in bone mass could be related to the type of weight-bearing loading and muscle strength. The group of soccer players consisted of 16 second-division female players (age 20.9 +/- 2.2 years) training for about 6 hours/week. The reference group consisted of 13 nonactive females (age 25.0 +/- 2.4 years) not participating in any kind of regular or organized sport activity. The groups were matched according to weight and height. Areal bone mineral density (BMD) was measured in total body, head, lumbar spine, femoral neck, Ward's triangle, trochanter, the whole femur and humerus, and in specific sites in femur diaphysis, distal femur, proximal tibia, and tibia diaphysis using dual X-ray absorptiometry. Isokinetic concentric peak torque of the quadriceps and hamstring muscles was measured using an isokinetic dynamometer. The soccer players had significantly (P < 0.05-0.01) higher BMD in the lumbar spine (10.7%), femoral neck (13.7%), Ward's triangle (19.6%), nondominant femur and humerus (8.2 and 8.0%, respectively), distal femur (12.6%), and proximal tibia (12.0%) compared with the nonactive women. There was no significant difference in muscle strength of the thigh between the two groups. In the nonactive group, muscle strength in the quadriceps and especially hamstrings, was correlated to BMD of the adjacent bones (whole femur, hip sites) and also to distant sites (humerus). In the soccer group, there were no correlations between muscle strength and BMD of the adjacent and distant bones. Soccer playing and training appears to have a beneficial effect on bone mass in young females, and it seems that there is a site-specific skeletal response to the type of loading subjected to each BMD site. Muscle strength in the thigh is not related to bone mass in female soccer players.
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| 7. |
- Pettersson, Ulrika, et al.
(författare)
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Bone mass in female cross-country skiers : relationship between muscle strength and different BMD sites.
- 2000
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 0171-967X .- 1432-0827. ; 67:3, s. 199-206
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Tidskriftsartikel (refereegranskat)abstract
- In this cross-sectional study, bone mass and muscle strength of the thigh were investigated in 16 Caucasian female cross-country skiers, age 16.2 +/- 0.3 years, that had been ski-training for 6.4 +/- 1.8 years (range 3-9 years) and were now training for 6.3 +/- 2.4 hours/week (range 3-12 hours). They were compared with 16 nonactive females, age 16.4 +/- 0.7 years. The groups were matched according to age, weight, height, and pubertal status. Areal bone mineral density (BMD) was measured using dual energy X-ray absorptiometry, in the total body, head, both total humerus and humerus diaphyses, spine, and in the right femoral neck, greater trochanter, femoral diaphysis, distal femur, proximal tibia, and tibia diaphysis. Bone mineral apparent density (BMAD) was also calculated for the femoral neck and humerus diaphyses. Isokinetic muscle strength of the quadricep and hamstring muscles was measured in an isokinetic dynamometer. Compared with the controls, the cross-country skiing group had significantly higher BMD in the right whole humerus (6.9%), left whole humerus (9.2%), left humerus diaphysis (8.1%), femoral neck (8.9%), greater trochanter (9.3%), femur diaphysis (7.6%), and BMAD of the femoral neck (+19.4%). In the nonactive group there were significant side-to-side differences in BMD of the whole humeri, humerus diaphyses, and BMAD of the humerus diaphyses (3.1%, 5.4%, and 8.8% higher in the right arm, respectively). No such differences were found in the cross-country skiing group. Lean body mass was significantly higher in the cross-country skiers (21.7%), and fat mass (-25.5%) and body fat percent (-28.0%) were significantly lower compared with the nonactive group. There were, however, no significant differences in concentric peak torque of the thigh muscles between the two groups. Stepwise regression analyses revealed that BMI was the best predictor of several sites in the nonactive group. In the cross-country group, on the other hand, muscle strength was a strong predictor of BMD, both at adjacent and more distant BMD sites. In conclusion, it seems that this type of endurance training is associated with a site-specific higher bone mass that may be associated with the type and magnitude of loading during off-season and during the main sports activity, cross-country skiing.
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| 8. |
- Pettersson, Ulrika, et al.
(författare)
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Effect of high impact activity on bone mass and size in adolescent females : A comparative study between two different types of sports.
- 2000
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 0171-967X .- 1432-0827. ; 67:3, s. 207-214
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this cross-sectional study was to investigate the influence of two different types of weight-bearing activity, muscle strength, and body composition on bone mineral density (BMD), bone mineral content (BMC), and bone area in three different groups of late adolescent girls. The first group consisted of 10 females participating in competitive rope-skipping (age 17.8 +/- 0.8 years) training for 6.7 +/- 3.1 hours/week; the second group consisted of 15 soccer players (age 17.4 +/- 0.8 years) training for 6.1 +/- 2.0 hours/week; and the third group consisted of 25 controls (age 17.6 +/- 0.8 years) with physical activity of 0.9 +/- 1.1 hours/week. The groups were matched for age, height, and weight. BMD (g/cm(2)), BMC (g), and bone area (cm(2)) of the total body, lumbar spine, hip, total femur, distal femur, diaphyses of femur and tibia, proximal tibia, and humerus were measured using dual-energy X-ray absorptiometry (DXA). Bone density was also assessed in the radial forearm site of the dominant limb in the rope skippers and in 10 matched controls. The rope skippers had 22% higher BMD at the ultradistal site (P < 0.01). Both high-activity groups had significantly higher BMD (P < 0.05) at most loaded sites compared with the control group. When adjusting for differences in lean mass and starting age of sport-specific training between the activity groups, the rope-skipping group had a higher BMD of the total body, lumbar spine, and right humerus compared with the soccer group. They also had a significantly higher bone area of the total body, total femur, and the proximal femur than both other groups, and a significantly higher bone area of the tibia diaphysis, compared with the soccer group. In a multivariate analysis among all subjects (n = 50), all BMD sites, except the femur diaphysis, distal femur, and proximal tibia, were significantly related to type of physical activity (beta = 0.25-0.43, P < 0.05). The bone area values at different sites were strongly related to muscle strength and parameters related to body size [height, weight, lean mass, fat mass, and body mass index (BMI)]. In conclusion, it appears that in late adolescent women, weight-bearing activities are an important determinant for bone density, and high impact activities such as jumping also seem to be associated with a modification of the bone geometry (hence, the bone width) at the loaded sites.
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| 9. |
- Söderman, Kerstin, et al.
(författare)
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Bone mass and muscle strength in young female soccer players.
- 2000
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 0171-967X .- 1432-0827. ; 67:4, s. 297-303
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Tidskriftsartikel (refereegranskat)abstract
- In this cross-sectional study, bone mass and muscle strength of the thigh were investigated in 51 female soccer players, age 16.3 +/- 0. 3 years, who had been playing soccer for 8.1 +/- 2.1 years and were at the time of the study in soccer training for 5.0 +/- 1.7 hours/week. They were compared with 41 nonactive females, age 16.2 +/- 1.3 years. The groups were matched according to age, weight, and height. Areal bone mineral density (BMD) was measured of the total body, head, lumbar spine, femoral neck, Ward's triangle, and the greater trochanter using dual energy X-ray absorptiometry (DXA). Isokinetic muscle strength of the quadriceps and hamstrings muscles was measured using an isokinetic dynamometer. Compared with the nonactives, the soccer players had significantly higher BMD of the total body (2.7%), lumbar spine (6.1%), the dominant and nondominant hip (all sites). The largest differences were found in the greater trochanter on both sides (dominant, 16.5%, nondominant, 14.8%). The soccer players had significantly higher concentric and eccentric peak torque of the thigh muscles. In the soccer group, there was only a positive association between thigh muscle strength and BMD of the adjacent hip, and in the nonactive group there were several positive associations between muscle strength and BMD. However, when adjusting for the variation in weight and height all these associations became nonsignificant. Using multiple linear regression, the type of activity (soccer player, nonactive) independently predicted BMD of all dominant hip sites (beta = 0.32-0.48, P < 0.01). No other variable was found to independently predict BMD of any site. In the younger subjects ( 16 years) the soccer players had significantly higher BMD in all measured sites except for the nonweight-bearing head. The differences in muscle strength between soccer players and nonactives were already seen in the young age group. In conclusion, girls who train and play soccer in adolescence have a higher bone mass in the hip and lumbar spine, and a higher muscle strength of the thigh compared with nonactive controls, indicating a site-specific skeletal response of weight-bearing and impact-loadng acting on the skeleton. The differences in bone mass were already apparent in early adolescence, but became more pronounced in late adolescence, probably explained by a longer exposure to soccer training with time. Our results also indicate that muscle strength in itself might not be of decisive importance for bone mass in the hip of adolescent females.
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