Posture control during a dual-task involves changing the distribution of attention resources between the cognitive and motor tasks and involves the frontal cortex working memory (WM). The present study aimed to better understand the impact of frontal lobe activity and WM capacity in postural control during a dual-task. High and low WM-span groups were compared using their reading span test scores. High and low WM capacity were compared based on cognitive and balance performance and hemoglobin oxygenation (oxyHb) levels during standing during single (S-S), standing during dual (S-D), one leg standing during single (O-S), and one leg standing during dual (O-D) tasks. For sway pass length, significant difference in only the O-D task was observed between both groups. oxyHb levels were markedly increased in the right dorsolateral prefrontal cortex and supplementary motor area in the high-span group during a dual-task. Therefore, WM capacity influenced the allocation of attentional resources and motor performance.

The purpose of this study was to investigate the differences in three-dimensional carpal kinematics between type 1 and 2 lunates. We studied 15 instances of wrist flexion to extension (nine type 1, six type 2), 13 of radial to ulnar deviation (seven type 1, six type 2), and 12 of dart-throwing motion (six each of type 1 and 2) in 25 normal participants based on imaging with computerized tomography. Mean proximal translation of the distal articular midpoint of the triquetrum relative to type 2 lunates during wrist radioulnar deviation was 2.9 mm (standard deviation (SD) 0.7), which was significantly greater than for type 1 lunates, 1.6 mm (SD 0.6). The hamate contacted the lunate in ulnar deviation and ulnar flexion of wrists with type 2 lunates but not with type 1. We conclude that the four-corner kinematics of the wrist joint are different between type 1 and 2 lunates.

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Medial elbow injuries lead to significant performance decrement in baseball.Repetitive throwing alters mechanical physiology. Some of such changes can increase the risk of medial elbow injuries. However, in young baseball players with medial elbow injuries, these changes have not been fully investigated. Thus, the purpose of this study was to investigate the mechanical physiological changes in young baseball players with medial elbow injuries. Sideto-side differences in (1) range of motion (ROM) of shoulder external rotation (ER)/internal rotation (IR), elbow flexion/extension, forearm supination/pronation, trunk rotation, and hip ER/IR; (2) strength of middle trapezius, lower trapezius (LT), and supraspinatus muscles, and shoulder ER/IR; and (3) medial elbow laxity were measured. Side-to-side differences were significant (p < 0.05). ROM of shoulder ER/IR, elbow flexion/extension, forearm pronation, and hip IR on the throwing side were significantly decreased compared to the non-throwing side. Trunk rotation in the direction of the throwing side was significantly decreased compared to the non-throwing side. LT and shoulder IR strength on the throwing side were significantly greater, while shoulder ER strength on the throwing side was significantly weaker than the non-throwing side. Medial elbow joint space of the throwing side was significantly wider than the nonthrowing side. In other measurements, no significant differences were observed between the throwing and non-throwing side. According to our findings, young baseball players with medial elbow injuries experience many side-to-side differences in mechanical physiology. The most interesting finding was that younger players with medial elbow injuries displayed decreased shoulder ER ROM, versus an increase reported in many previous studies.

The ROM of the wrist in the DTM plane was measured with fair-to-good reliability and responsiveness and, therefore, has the potential to become an evaluation tool for rehabilitation.