The Effect of Whole-Body Fatigue on King-Devick Test and Balance.

Purpose: Fatigue may mimic suboptimal brain functioning seen after a concussion and lead to false-positive King-Devick (K-D) scores and decreased balance. The purpose of this study was to investigate if whole-body fatigue has an effect on K-D scores or postural sway. Method: A total of 38 healthy participants (20 females; age = 23.5 ± 2.63 y; height = 170 ± 0.1 cm; mass = 75.2 ± 10.3 kg) volunteered for the study. Participants completed the King-Devick (K-D) test and the modified Clinical Test of Sensory Interaction of Balance (mCTSIB) on the Biodex BioSwayTM Portable Balance System prior to and immediately following the completion of a fatigue protocol on a Concept2 Rower. Results: Half of the participants demonstrated a positive K-D test post-fatigue. Balance scores were poorer post-fatigue. No difference was found between participants based on history of concussion. Among the participants that had a positive post-fatigue K-D test, 71% had also a worse composite sway index score (χ2 = 6.3, p = .02). Conclusions: Whole-body fatigue may negatively impact a person's ability to perform the K-D test and balance assessments. It is recommended that the athlete is allowed a period of time to accommodate for the acute effects of fatigue before administering these assessments following a suspected concussion.

Shoulder strength and range of motion in female amateur-league tennis players.

STUDY DESIGN: Cross sectional. OBJECTIVES: To compare the strength and range of motion of the dominant and nondominant shoulders of adult female amateur tennis players. The secondary purpose of the study was to examine whether there were any differences in the observed relationships between women with a past history of shoulder pain and those with no history of shoulder pathology. BACKGROUND: Information on characteristics of the shoulder in amateur female tennis players is scarce, as research has concentrated on highly skilled or male players, despite the cumulative prevalence of shoulder pain in this group. METHODS AND MEASURES: Fifty-one female competitive, amateur tennis players (average age, 45 years) were tested bilaterally for shoulder internal/external rotation passive range of motion and isokinetic concentric strength. RESULTS: Shoulder range of motion and strength ratios were comparable between sides. In the dominant arm, the total rotational range of motion was 221 degrees, with an internal to external rotator peak torque ratio of 1.05. External rotator strength was significantly greater in the dominant arm of individuals with no history of pain. CONCLUSIONS: Range of motion and strength adaptations widely reported in highly skilled tennis players were not apparent in amateur female players. In assessment and management, clinicians should regard the amateur female tennis player as a separate entity from the highly skilled player.