| Reference* | Design | Study population | Method | Main results |
| Ducher et al85 | XS | 28 young (22 boys, 6 girls, 11.6 (1.4) y) and 47 adult tennis players (23 M, 24 F, 22.3 (2.7) y), and 70 age matched controls (12 children (12.2 (1.6) y) and 58 adults (23.3 (3.2) y)) | DXA | At the ultradistal radius, asymmetry in BMC in young and adult tennis players was 16.35% and 13.8%, respectively (p<0.0001). At the mid- and third-distal radius, asymmetry was much greater in adults than in children (p<0.0001) for BMC (mid-distal radius, +6.6% v +15.6%; third-distal radius +6.9% v +13.3%). |
| Ducher et al82 | XS | 52 tennis players (24.2 (5.8) y), 16.2 (6.1) y of practice | DXA | Lean tissue mass, bone area, BMC, and BMD of the dominant forearm were significantly (p<0.0001) greater. Bone area and BMC correlated with grip strength on both sides (r = 0.81–0.84, p<0.0001). |
| Ducher et al83 | XS | 20 regional level tennis players (10 M; 10 F, mean age 23.1 (4.7) years, with 14.3 (3.4) years of playing) | DXA | Significant side-to-side differences (p<0.0001) were found in muscle volume (+9.7%), grip strength (+13.3%), BMC (+13.5%), total bone volume (+10.3%), and subcortical volume (+20.6%), but not in cortical volume (+2.6%, NS). The asymmetry in total bone volume explained 75% of the variance in BMC asymmetry (p<0.0001). Volumetric BMD was slightly higher on the dominant side (+3.3%, p<0.05). Grip strength and muscle volume correlated with all bone variables (except volumetric BMD) on both sides (r = 0.48–0.86, p<0.05–0.0001) but the asymmetries in muscle indices did not correlate with those in bone indices. |
| Ducher et al84 | XS | 57 regional level tennis players (33 M, 24 F). All had been practising tennis for at least 5 years | DXA | At the ultradistal radius, the side-to-side difference in BMD was larger than in bone area (8.4 (5.2)% and 4.9 (4.0)%, respectively, p<0.01). In he cortical sites, the asymmetry was lower (p<0.01) in BMD than in bone area (mid-distal radius: 4.0 (4.3)% v 11.7 (6.8)%; third-distal radius: 5.0 (4.8)% v 8.4 (6.2)%). |
| Sanchis-Moysi et al66 | XS | 10 F postmenopausal tennis players (60 (5) y) and 12 postmenopausal controls (63 (7) y). Tennis players started at 31 (9) y and had been playing for 27 (7) y, at least 3 h/wk | DXA | Tennis players showed 8% greater BMC and 7% greater osseous area in the dominant arm than in the non-dominant arm (p<0.05). There was a positive correlation between duration of tennis participation and inter-arm asymmetry in BMC (r = 0.81, p<0.01) and bone area (r = 0.78, p<0.01). |
| Sanchis Moysi et al65 | XS | 17 M tennis players (55 (2) y), 9 F tennis players (61 (1) y), 15 M (56 (3) y) and 20 F (62 (2) y) control subjects. Mean tennis participation was 27 (7) y, 3 h/wk | DXA | Male tennis players had a 16% higher BMC and 10% BMD in legs than controls (p<0.05). 10–30% greater BMC and BMD were observed in the hip region and lumbar spine (L2–L4) of tennis players v controls (p<0.05). |
| Kontulainen et al80 | XS | 36 young F Finnish tennis/squash players (22 (8) y, mean starting age 11 (2) y), and 28 older F players (39 (11) y, mean starting age 26 (8) y), and 27 controls (29 (10) y) | pQCT, DXA | The side-to-side differences in the young starters bone mineral content, cortical area, total cross sectional area of bone, and cortical wall thickness were 8–22% higher than those of controls and 8–14% higher than those of old starters. |
| Nara-Ashizawa et al68 | XS | 92 middle aged F tennis players (46 (5) y) who initiated training after bone had matured (mean starting age 36 (3) y) | pQCT | Endocortical area (0.278 (0.094) v 0.300 (0.106) cm2), periosteal area (1.007 (0.14) v 1.061 (0.15) cm2), BMC (0.141 (0.017) v 0.147 (0.017) g), moment of inertia (1598 (413) v 1744 (460) mm4), section modulus (219 (41) v 233 (44) mm3), and SSI (352 (66) v 376 (71) mm3) of dominant midradius were greater (p<0.01) than in the non-dominant radius. BMD of trabecular bone (0.383 (0.060) v 0.363 (0.070) g/cm3, p<0.05) and whole bone (0.756 (0.115) v 0.656 (0.120) g/cm3, p<0.01) at the dominant distal radius were greater than in the non-dominant radius. |
| Kontulainen et al64 | PCS; 5-y follow up | 36 young F Finnish tennis/squash players (22 (8) y, mean starting age 11 (2) y), and 28 older female players (39 (11) y, mean starting age 26 (8) y), and 27 controls (29 (10) y). Young starters reduced training from 4.7 (2.7) to 1.4 (1.3) times/wk; old starters from 4.0 (1.4) to 2.0 (1.4) times/wk | DXA | Bone gain was 1.3–2.2 times greater in favour of young starters: The difference in BMC of humeral shaft in dominant v non-dominant arm was 22 (8.4)% in young starters v 10 (3.8)% in old starters at follow up. |
| Haapasalo et al67 | XS | 12 M former Finnish national level tennis players (30 (5) y) and 12 age, height, and weight matched controls | pQCT | Among the players significant side-to-side differences (p<0.05) in favour of the dominant arm were found in BMC, total area, cortical area, and bone strength index at the proximal humerus, humeral shaft, distal humerus, radial shaft, and distal radius. Increased bone strength was mainly due to increased bone size and not to a change in volumetric bone density. |
| Kontulainen et al63 | PCS; 4-y follow up | 13 M former competitive tennis players (26 (5) y) who started their career at a mean age of 11 y and 13 controls (26 (6) y). The players had all retired from top tennis before (mean 2.3 (0.6) y) follow up | DXA | Relative side-to-side BMC differences were significantly (p<0.001) larger in players than in controls at all measured sites in both 1992 and 1996 for proximal humerus (1992: 18.5% v 1.4%; 1996: 18.4% v 0.5%), humeral shaft (1992: 25.2% v 4.7%; 1996: 25.9% v 4.5%), radial shaft (1992: 13.9% v 1.8%; 1996: 14.2% v 2.1%), and distal radius (1992: 13.2% v 2.0%; 1996: 13.2% v 2.3%). |
| Ashizawa et al69 | XS | Forearms of 16 competitive tennis players (10 F) and 12 healthy controls (7 F) aged 18–24 y were scanned at mid and distal site of the radius | pQCT | Players had an increase in total BMC (13.3%, p<0.001), periosteal bone area (15.2%, p<0.001), cortical BMC (12.6%, p<0.001), and cortical bone area (13.5%, p<0.01) in the playing arm v the non-playing arm. In controls, side-to-side differences in these variables were not significant. |
| In the distal radius, total BMC (13.8%, p<0.01), periosteal bone area (6.8%, p<0.05), total BMD (6.8, p<0.01), trabecular bone area (6.8%, p<0.05), and trabecular BMD (5.8%, p<0.05) of the playing arm were greater than in the non-playing arm. In controls, significant side-to-side differences were not found in any measured variables. | ||||
| Haapasalo et al70 | XS | 91 7–17 y F tennis players and 58 healthy F controls. In each Tanner stage, differences in BMD in playing and non-playing arms and lumber spine were compared between the players and controls | DXA | In players, BMD inter-arm differences were significant (p<0.05 to <0.001) in all Tanner stages, with mean differences ranging from 1.6% to 15.7%. Mean arm differences between players and controls did not become obvious until Tanner stage III (mean age 12.6 y). In the lumbar spine differences were not found until Tanner stage IV (mean age 13.5 y, 0.97 (0.13) v 0.89 (0.09) g/cm2, p<0.05) and Tanner stage V (mean age 15.5 y, 1.08 (0.105) v 0.96 (0.134) g/cm2, p<0.05). |
| Calbet et al71 | XS | 9 M professional tennis players (26 (6) y) and 17 non-active M subjects (24 (3) y) | DXA | Total mass (4977 (908) v 4220 (632) g, lean mass (3772 (500) v 3246 (421) g, p<0.001, and BMC (229 (43.5) v 194 (33) g) were greater in the dominant arm of tennis players than in controls (all p<0.05). BMD was increased in tennis players v controls in the lumbar spine (1.25 (0.29) v 1.09 (0.12) g/cm2, p = 0.09) and in the trochanteric region (0.94 (0.11) v 0.80 (0.07) g/cm2, p<0.001). |
| Haapasalo et al72 | XS | 17 young competitive M tennis players (25 (5) y), 30 young F players (19 (3) y), 20 older F players (43 (5) y), 16 M controls (25 (5) y), 25 young F controls (21 (3) y), and 16 older F (39 (6) y). Starting age, M 10 (3) y, young F 9 (2) y, older F 29 (6) y | DXA | There were significant side-to-side humeral length differences in young M players (+1.4%), young F controls (+1.1%), and older F players (+0.7%). Relative side-to-side differences in BMC (range +7.6 to +25.2%), BMD (range +5.8% to +22.5%), cortical wall thickness (range +6.9% to +45.2%), cross sectional moment of inertia (range +7.8% to +26.4%), and section modulus (range +3.0% to +21.7%) were significantly larger in players than in controls at the proximal, mid, and distal part of the humerus. Relative side-to-side differences were significantly larger in young (range +11.7% to +45.2%) than in older players (range +3.0% to +12.4%). |
| Etherington et al73 | XS | 16 former tennis players (aged 40–65 y), 67 former middle and long distance runners and 585 age matched controls | DXA | Tennis players had greater BMD than runners (lumbar spine 12% (95% CI, 5.7 to 18.2), p = 0.0004, femoral neck 6.5% (–0.2 to 13.2), p = 0.066). Athletes had greater BMD than controls (lumbar spine 8.7% (5.4 to 12.0), p<0.001 and femoral neck 12.1% (9.0 to 15.3), p<0001). BMD of tennis players’ forearms were greater than their non-dominant forearms. |
| Tsuji et al74 | XS | 10 M college wrestlers (20 (1) y), 16 female college basketball players (20 (1) y), and 12 F college tennis players (21 (1) y) | DXA | A significant and positive relation was found between mid-radial (0.48 (0.07) g/cm2) BMD and grip strength (31.2 (4.1) kg) in the dominant forearm of tennis players (r = 0.43, p<0.05). There was a significant difference between mid-radial BMD in the dominant (range 0.63–0.87 g/cm2) and non-dominant arm (range 0.52–0.57 g/cm2, p<0.05). |
| Kannus et al75 | XS | 105 F Finnish national level tennis/squash players (28 (11) y) and 50 controls (27 (9) y). Players were divided into starting groups according to the biological age (y before or after menarche) at which their playing careers began | DXA | The players had a larger (p<0.001) side-to-side difference in BMC for proximal humerus (1.42 (1.33) v 0.41 (1.08) g), humeral shaft (2.77 (2.20) v 0.57 (1.68) g), radial shaft (0.32 (0.47) v 0.12 (0.40) g), and distal radius (0.32 (0.38) v 0.11 (0.28) g). Differences were two to four times greater in players who started before or at menarche than 15 years after menarche. |
| Kannus et al76 | XS | 20 top level M Finnish tennis players (25 (5) y), and 20 controls (26 (5) y) | DXA | Relative side-to-side differences in BMD and BMC were significantly increased in players v controls for humeral shaft (BMD 0.29 (0.09) v 0.03 (0.10) g/cm2, BMC 6.41 (0.28) v 1.06 (0.33) g, p<0.001), and proximal humerus (BMD 0.12 (0.08) v 0.01 (0.10) g/cm2, BMC 2.38 (1.8) v 0.28 (1.7) g, p<0.001). |
| Krahl et al77, 78 | XS | 20 highly ranked professional tennis players (12 M, 8 F, 20.1 (4.5) y), and 12 controls (7 M, 5 F, 23.1 (4.7) y) | x ray | Relative side-to-side differences were significantly increased in tennis players v controls for ulnar diameter (2.1 v 0.02 mm, p<0.01), ulnar length (8 v 0.17 mm, p<0.01), second metacarpal diameter (0.9 v 0.0 mm, p<0.01), and second metacarpal length (2.7 v 0 mm, p<0.01). |
| Jacobson et al79 | XS | 11 college tennis players, 23 swimmers, and 86 older athletic F aged 23 to 75 y and age matched non-athletic controls. | Single and dual photon densitrometry | Lumbar spine density was increased in tennis players v swimmers and controls (1.51 (37) v 1.39 (27) and 1.36 (49) g/cm2, p<0.02). Metatarsal density was increased in tennis players v swimmers and controls (626 (26) v 565 (14) and 512 (13) g/cm2, p<0.001). BMC of dominant arm of tennis players 16% higher than in non-dominant arm; in controls ⩽3% (p<0.001). Differences between controls and athletic women were highest in oldest age groups. |
| Huddleston81 | XS | 35 active M tennis players were studied during the 1978 USTA’s 70-, 75-, and 80-y age group clay court championship (21 aged 70–74 y, 9 aged 75–79 y, 5 aged 80–84 y | Transmission scanning with a low energy x-ray beam | Bone mass of the radius of the playing arm (mean, 1.37 g/cm) was greater than that of the non-playing arm (mean, 1.23 g/cm) in all but one person. The quantity of BM present in the playing arms of the tennis population was greater than that of the dominant arm on non-athletes. |
*First author and year of publication.
BMC, bone mineral content; BMD, bone mineral density; CI, confidence interval; DXA, dual energy x ray absorptiometry; F, female; M, male; PCS, prospective cohort study; pQTC, peripheral quantitative computer tomography; wk, week; XS, cross sectional study; y, years.