Table 2. Lower-limb kinematic parameter difference between adolescent and collegiate pitchers. Values are expressed as mean (±SD).
Variable Adolescentpitcher (n = 32) Collegiatepitcher (n = 30) ES Adolescentpitcher (n = 32) Collegiatepitcher (n = 30) ES
Phase time / Strength length
Phase 1 time (s) .9 (.2) .9 (.3) .03
Phase 2 time (s) .2 (.0) .2 (.0) .27
Total Pitch Time (s) 1.1 (.2) 1.1 (.3) .01
Stride length (m) 1.4 (.1) 1.5 (.1)** 1.33
Stride length (%height) 82.9 (6.1) 84.6 (4.2) .33
Angles Pivot leg Stride leg
Hip Coronal Plane (Adduction:+; Abduction:- )
Angle at MKH (°) -23.1 (5.8) -24.6 (5.9) .26 20.9 (14.9) 24.1 (12.8) .23
Angle at MAP (°) -25.9 (9.8) -19.7 (9.8)* .62 -31.7 (13.5) -21.0 (13.2)** .78
Angle at SFC (°) -42.5 (4.5) -42.1 (5.4) .08 -38.5 (6.8) -38.1 (6.0) .06
Angle at MER (°) 27.7 (18.8) 26.2 (21.7) .08
Angle at REL (°) 33.9 (16.7) 37.1 (14.0) .20
Hip Transverse Plane (Internal Rotation:+; External Rotation:- )
Angle at MKH (°) -18.3 (7.1) -23.8 (6.0)** .83 -32.7 (10.3) -39.9 (11.6) * .64
Angle at MAP (°) -25.1 (6.5) -31.0 (8.2)** .79 -39.3 (9.5) -38.3 (8.2) .11
Angle at SFC (°) -21.9 (8.8) -25.5 (8.2) .41 -45.4 (8.3) -48.5 (8.6) .37
Angle at MER (°) -22.0 (12.2) -23.7 (9.3) .15
Angle at REL (°) -18.3 (10.4) -16.1 (8.8) .22
Hip Sagittal Plane (Flexion:+; Extension:- )
Angle at MKH (°) 15.4 (7.7) 16.3 (6.2) .13 100.3 (10.3) 108.9 (6.8)** .96
Angle at MAP (°) 51.0 (10.0) 59.2 (8.7) ** .86 45.0 (13.1) 46.0 (14.1) .07
Angle at SFC (°) 20.5 (14.2) 23.5 (13.7) .21 58.1 (11.1) 61.9 (12.5) .31
Angle at MER (°) 105.4 (14.2) 109.4 (13.8) .28
Angle at REL (°) 97.9 (15.5) 106.2 (10.0)* .62
Knee Sagittal Plane (Flexion:+; Extension:- )
Angle at MKH (°) 16.0 (7.0) 17.0 (6.4) .14 111.1 (18.5) 112.0 (13.5) .05
Angle at MAP (°) 50.3 (9.2) 49.5 (9.4) .09 35.9 (17.9) 33.4 (15.0) .15
Angle at SFC (°) 30.8 (13.1) 28.1 (10.2) .22 40.0 (8.2) 46.8 (8.5)** .80
Angle at MER (°) 39.0 (12.1) 44.2 (10.9) .44
Angle at REL (°) 31.4 (15.6) 38.0 (13.7) .44
Ankle Sagittal Plane (Dorsiflexion:+; Plantar flexion:- )
Angle at MKH (°) 2.3 (5.3) 2.1 (6.9) .03 .6 (18.4) 11.6 (14.2)* .66
Angle at MAP (°) -5.9 (9.6) -1.4 (9.5) .46 6.8 (11.5) 10.8 (11.4) .35
Angle at SFC (°) 21.8 (17.8) 31.6 (10.3) * .66 13.3 (12.8) 16.6 (14.4) .24
Angle at MER (°) 19.2 (5.5) 19.7 (5.8) .08
Angle at REL (°) 20.9 (6.5) 21.4 (6.1) .08
Joint Angular Velocities Pivot leg Stride leg
Max Hip Flex Angle (°) 57.9 (9.3) 62.6 (8.1) * .52 106.4 (13.8) 112.5 (8.8)* .51
Max Knee Flex Angle (°) 58.6 (9.9) 56.7 (10.1) .19 47.8 (7.1) 51.7 (8.3) .49
Max Hip Add AV (°/s ) 117.9 (66.0) 140.7 (47.3) .39 852.0 (213.9) 830.6 (160.9) .11
Max Hip Abd AV (°/s ) 248.0 (73.7) 279.8 (78.4) .41 123.3 (137.9) 38.8 (116.4)* .65
Max Hip IntRot AV (°/s ) 110.8 (77.6) 171.0 (122.7) * .58 459.7 (13.8) 499.7 (157.3) .27
Max Hip ExtRot AV(°/s ) 72.0 (26.5) 69.1 (25.0) .11 82.4 (89.0) 59.0 (63.1) .30
Max Hip Flex AV (°/s ) 133.5 (41.5) 140.1 (40.1) .16 609.5 (98.8) 632.9 (107.0) .22
Max Hip Ext AV (°/s ) 515.6 (111.8) 549.1 (100.8) .30 262.7 (102.2) 204.2 (98.5)* .57
Max Knee Ext AV (°/s ) 239.0 (85.4) 230.0 (76.6) .11 245.7 (95.1) 220.9 (117.8) .23
Knee Ext AV at MER (°/s ) 167.9 (126.0) 132.1 (122.8) .28
Knee Ext AV at REL (°/s ) 199.4 (109.0) 161.1 (117.3) .33
ES; Effect Size value; MKH; Maximal stride knee height. MAP; Maximal anterior push-off force. SFC; Stride foot contacts ground. MER; Maximum shoulder external rotation. REL; Ball release. AV: Angular Velocity; Max: Maximum; Flex: Flexion; Ext: Extension; Add: Adduction; Abd: Abduction; IntRot:Internal Rotation; ExtRot: External Rotation.
* p < 0.05, Significant difference between adolescent and collegiate pitchers.
** p < 0.01, Significant difference between adolescent and collegiate pitchers.