Six core scales were identified with a broad range of symptom items but with limited information on their psychometric properties .
OBJECTIVE To identify  self-reported sport concussion symptom scales  and to describe the psychometric properties of these identified scales .
Recovery of postural control after cerebral concussion: new insights using approximate entropy.
CONTEXT The return-to-play decision after sport-related cerebral concussion depends in part on knowing when an athlete has fully recovered postural control after injury . OBJECTIVE To describe the postconcussion recovery of postural control using approximate entropy ( ApEn ) , a regularity statistic from nonlinear dynamics . DESIGN Retrospective case series analysis . SETTING Sports medicine research laboratory . PATIENTS OR OTHER PARTICIPANTS Collegiate athletes from whom center-of-pressure and symptom data were collected at preseason , less than 48 hours after injury , and 48 to 96 hours after injury . MAIN OUTCOME MEASURE(S ) Approximate entropy values reflecting the amount of r and omness contained in center-of-pressure oscillations were calculated for anterior-posterior ( AP ) and medial-lateral ( ML ) time series . Equilibrium scores reflecting the amplitude of center-of-pressure AP oscillations were used to indicate postural stability . The number and severity of symptoms were described . RESULTS Compared with the healthy preseason state , ApEn values for the AP and ML time series generally declined immediately after injury in both steady and unsteady injured athletes . At 48 to 96 hours after injury , ApEn values for the ML time series remained significantly depressed ( mean difference compared with preseason = -0.268 , st and ard error = 0.072 ) , even among athletes whose initial postural instability had resolved . We found few significant relationships between changes in ApEn values and changes in symptoms before and after injury . CONCLUSIONS The effects of cerebral concussion on postural control appear to persist for longer than 3 to 4 days , even among athletes with no signs of unsteadiness . Our results may reflect changes in neurophysiologic or mechanical constraints on postural control . Approximate entropy provides a theoretically distinct , valuable measurement alternative that may prove useful for reducing uncertainty in the return-to-play decision
Six core scales were identified with a broad range of symptom items but with limited information on their psychometric properties .
OBJECTIVE To identify  self-reported sport concussion symptom scales  and to describe the psychometric properties of these identified scales .