Scott Ross, Kevin Guskiewicz, William Prentice, Robert Schneider and Bing Yu
T o determine differences between contralateral limbs’ strength, proprio-ception, and kinetic and knee-kinematic variables during single-limb landing.
Hip, knee, and foot isokinetic peak torques; anterior/posterior (AP) and medial/lateral (ML) sway displacements during a balance task; and stabilization times, vertical ground-reaction force (VGRF), time to peak VGRF, and knee-flexion range of motion (ROM) from initial foot contact to peak VGRF during single-limb landing.
The kicking limb had significantly greater values for knee-extension (P = .008) and -flexion (P = .047) peak torques, AP sway displacement (P = .010), knee-flexion ROM from initial foot contact to peak VGRF (P < .001), and time to peak VGRF (P = .004). No other dependent measures were significantly different between limbs (P > .05).
The kicking limb had superior thigh strength, better proprioception, and greater knee-flexion ROM than the stance limb.
Darin A. Padua, Kevin M. Guskiewicz, William E. Prentice, Robert E. Schneider and Edgar W. Shields
To determine whether select shoulder exercises influence shoulder-rotation strength, active angle reproduction (AAR), single-arm dynamic stability, and functional throwing performance in healthy individuals.
54, randomly placed in 4 training groups.
Four 5-week training protocols.
Main Outcome Measures:
Average shoulder-rotation torque, AAR, single-arm dynamic stability, and functional throwing performance.
Repeated-measures ANOVAs revealed a significant group-by-test interaction for average torque (P > .05). Post hoc analyses revealed significantly increased average torque in the open kinetic chain and proprioceptive neuromuscular facilitation (PNF) groups after training. AAR and sway velocity were not affected in any of the groups (P > .05), but functional performance revealed a significant group-by-test interaction (P < .05). Post hoc analysis demonstrated that the PNF group significantly improved after training (P < .05).
Shoulder strength can be improved in healthy individuals, but improvements depend on the exercise performed. Shoulder proprioception and neuromuscular control were unchanged in all groups, but functional performance improved in the PNF group
Amee L. Seitz, Michael Reinold, Robert A. Schneider, Thomas J. Gill and Charles Thigpen
Differences in 3-dimensional (3D) scapular motion have been reported between healthy baseball position players and healthy nonoverhead athletic controls, as well as players diagnosed with shoulder impingement syndrome. These alterations are theorized to be the result of adaptations due to the demands of repetitive throwing. However, comparisons between the throwing and nonthrowing shoulders are commonly used to infer normal motion.
The purpose of this study was to compare 3D scapular kinematics between the throwing and nonthrowing shoulders in asymptomatic professional male baseball pitchers.
45 asymptomatic professional baseball pitchers participating without restrictions during preseason training.
An electromagnetic tracking system was used to assess 3D scapular orientation at rest and during weighted (2.3-kg) shoulder flexion across discrete humeral-flexion angles (rest, 30°, 60°, 90°, 120°, and maximum).
Main Outcome Measure:
3D scapular upward/downward rotation (UR/DR), anteroposterior (AP) tilt, and internal/external rotation (IR/ER). Separate mixed-model ANOVAs (Side × Angle) for each scapular motion were used to compare the throwing and the nonthrowing shoulder across all angles.
There were significant side-to-side differences with scapular UR/DR (P < .001), AP tilt (P < .001), and IR/ER (P < .001). The throwing scapula displayed greater mean UR (increase = 3.6°, SE = 0.50) and anterior/posterior tilt (increase = 2.1°, SE = 0.60) and less mean IR (decrease = 2.1°, SE = 0.66) than the nonthrowing shoulder averaged across all arm angles.
In asymptomatic professional pitchers, the throwing shoulder’s scapular position differs across all arm angles from that of the nonthrowing shoulder, but the motion does not differ. Scapular asymmetry that is consistent throughout arm elevation may be indicative not of pathology but, potentially, of a normal adaptation of the pitching shoulder.