Biomedical subjects
D H Perrin
Publications and source records attributed to D H Perrin.
Effect of Trunk Position on Anterior Tibial Displacement Measured by the KT-1000 in Uninjured Subjects.
OBJECTIVE: Clinicians may obtain false-negative Lachman tests for tibial displacement when the trunk position of the athlete varies as the anterior cruciate ligament injury is assessed on the field, on the sideline, and in the clinic. We examined the influence of supine, semireclined, and sitting trunk positions on arthrometric laxity measurements of the knee. DESIGN AND SETTING: Subjects in the 3 trunk-thigh test positions (15 degrees , 45 degrees , and 90 degrees of hip flexion) were passively supported and tested in a counterbalanced order. The right knee was maintained at 29.0 degrees +/- 3.1 degrees of flexion. A 133-N (30-1b) anterior force was applied to the right knee using a modified KT-1000 knee arthrometer equipped with a strain gauge that allowed for digital display of the displacement force. SUBJECTS: Ten males and 5 females without present knee injury or history of knee ligament repair to the right lower extremity. MEASUREMENTS: Three tibial displacement (mm) trials at each trunk position were averaged and used for analysis. RESULTS: A 1-factor (trunk-thigh position) repeated-measures analysis of variance revealed no significant difference in anterior tibial displacement values among the 3 trunk-thigh positions (P > .05). Group means for displacement were 7.9 +/- 2.3 mm (supine), 8.1 +/- 2.5 mm (semireclined), and 8.3 +/- 2.6 mm (sitting). CONCLUSIONS: These findings suggest that alterations in trunk position are not a problem in the instrumented assessment of anterior tibial displacement in an uninjured population. Further research should determine the relevance of these findings, as well as "end-feel" (ie, stiffness) in subjects with injury to the anterior cruciate ligament. Further research should also determine if these findings can be applied when comparing passive versus active (eg, propped on elbows or hands) trunk support in subjects with anterior cruciate ligament-injured knees.
Importance of selected athletic trainer employment characteristics in collegiate, sports medicine clinic, and high school settings.
OBJECTIVE: We examined employer importance ratings of 35 employee characteristics in the collegiate, sports medicine clinic, and high school settings and made comparisons among these settings. DESIGN AND SETTING: All prospective employers were sent a survey. Of the 472 surveys mailed, 282 (60%) were returned, with a sample error rate of 1.9%. SUBJECTS: All prospective employers listed on the NATA position vacancy notices from January 1, 1994 to October 1, 1994. MEASUREMENTS: Employers were asked to rate 35 employee characteristics as "not important" " minimally important," " important." or "very important." Additionally, employers chose 1 of 15 job descriptors that best identified their position vacancy. These 15 descriptors were then categorized into collegiate, sports medicine clinic, and high school settings. Discriminant analysis and analysis of variance procedures were used to determine if the 35 employee characteristics differed across the 3 settings. RESULTS: The discriminant analysis produced 2 significant discriminant functions (P < .05) with 23 of the original 35 characteristics remaining in the analysis. The first function discriminated between the collegiate setting and the other settings, with the collegiate setting scoring the highest. The second function discriminated among all 3 groups, with the sports medicine clinic and high school settings scoring the highest and lowest, respectively. Additionally, the analyses of variance (ANOVAs) revealed that 21 of the characteristics remaining in the discriminant analysis differed across the 3 settings. CONCLUSIONS: Employers from all 3 settings rated educational program reputation, written recommendations, job interview performance, and NATA-BOC certification eligibility as important to very important. For the collegiate setting, 7 characteristics were rated above important and included such characteristics as possession of a master's degree and collegiate experience. For the sports medicine clinic, 8 characteristics were rated above important and included sports medicine clinic experience, high school experience, and sport-specific experience. Finally, for the high school setting, 5 characteristics were rated above important. These included NATA-BOC certification, a bachelor's degree, and high school experience.
Open and closed kinetic chain exercises improve shoulder joint reposition sense equally in healthy subjects.
OBJECTIVE: To compare the effects of open and closed kinetic chain exercise on shoulder joint reposition sense. DESIGN AND SETTING: Subjects with no previous upper extremity injury participated in a 6-week exercise program consisting of 3 sessions per week. SUBJECTS: Thirty-nine healthy male military cadets: 13 each in the open, closed, and control groups. MEASUREMENTS: Each subject was pretested and posttested for both active and passive joint reposition sense at 30 degrees external rotation, 30 degrees internal rotation, and 10 degrees from full external rotation. RESULTS: The open and closed kinetic chain groups de- creased in reposition sense error scores in comparison with the control group, but no difference was found between the 2 training groups. CONCLUSION: Our findings suggest that shoulder joint reposition sense can be enhanced with training in healthy subjects. Also, open and closed kinetic chain exercises appear to be equally effective in improving shoulder joint reposition sense.
Alternative approaches to the assessment of mild head injury in athletes.
OBJECTIVES: Athletic trainers and team physicians are often faced with decisions concerning the severity and timing of an athletes return to play following mild head injury (MHI). These decisions can be the most difficult ones facing clinicians because of the limited amount of quantitative information indicating injury severity. Several authors have published guidelines for return to play following MHI, however these guidelines are based on limited scientific data. The purpose of this paper was to examine the effects of MHI on two objective measures, postural stability and cognitive function, to determine their usefulness in MHI assessment. The data gathered from these two measures has the potential to establish recovery curves based on objective data. METHODS: Eleven Division I collegiate athletes who sustained a MHI and eleven matched control subjects were assessed for postural stability and cognitive function at four intervals following injury. Postural stability was assessed using the Sensory Organization Test on the NeuroCom Smart Balance Master. Cognitive functioning was measured through the use of four neuropsychological tests: Stroop Test, Trail Making Test, Digits Span and Hopkins Verbal Learning Test. Separate mixed model repeated measures ANOVAs were calculated for the composite score and three ratio (vestibular, visual and somato-sensory) scores from the Sensory Organization Test and the scores from the neuropsychological test to reveal significant differences between groups and across days postinjury. RESULTS: A significant group by day interaction for overall postural stability (composite score) revealed that MHI athletes displayed increased postural instability for the first few days following MHI (p < .05). Analysis of the ratio scores revealed a significant interaction for the visual ratio. No significant group differences were revealed for any of the neuropsychological tests (p > .05), however significant day differences were revealed (p < .05). CONCLUSIONS: The results from this study indicate that athletes demonstrate decreased stability until 3 days postinjury. It appears this deficit is related to a sensory interaction problem, whereby the injured athlete fails to use their visual system effectively. These findings suggest that measures of postural stability may provide clinicians with a useful clinical tool for determining when an athlete may safely return to competition, although these findings need to be confirmed in larger groups of athletes.
A trend analysis of the in vivo quadriceps femoris angle-specific torque-velocity relationship.
To adequately assess isokinetic human muscle performance, it is important for clinicians to understand how the muscle functions across a range of velocities. Thus, the purpose of this study was to re-examine the in vivo quadriceps torque-velocity relationship using trend analysis. Twelve uninjured university-age females performed three concentric and eccentric contractions at velocities of 0, 25, 50, 75, 100, 125, 150, 175, and 200 degrees/sec on the Kin-Com isokinetic dynamometer. A trend analysis was performed on the angle-specific torques at 30, 60, and 75 degrees of knee flexion. The results indicated that the concentric and eccentric relationships at 30 degrees and the concentric relationship at 60 degrees were represented by a third-order polynomial, and a linear relationship was found for concentric contractions at 75 degrees. There were no significant trends for the eccentric relationship at 60 and 75 degrees, suggesting that they were best described by the grand mean. These results suggest that muscular torque production varies across velocities and contraction modes and that this relationship varies depending on the joint angle of torque measurement.
Comparison of nonballistic active knee extension in neural slump position and static stretch techniques on hamstring flexibility.
Nonballistic, active range of motion exercises have been advocated as more effective than static stretching for increasing range of motion, yet no published data exist to support this claim. This study compared the effect of nonballistic, repetitive active knee extension movements performed in a neural slump sitting position with static stretching technique on hamstring flexibility. Forty healthy, adult volunteer subjects with limited right hamstring flexibility (i.e., minimum of 15 degrees loss of active knee extension measured with femur held at 90 degrees of hip flexion) were randomly assigned to one of three groups. Group 1 (static stretch) performed a 30-second stretch twice daily. Group 2 (active stretch) performed 30 repetitions of active knee extension while sitting in a neural slump position twice daily. Group 3 served as a control. Hamstring flexibility was determined by an active knee extension test before and after 6 weeks of stretching. Goniometric measurement of knee joint flexion angle was obtained from videotape recording of the active knee extension test. A 3 (group) x 2 (test) repeated measures analysis of variance and subsequent Tukey post hoc testing revealed no significant difference in knee joint range of motion gains between the static (mean = 8.9 degrees) and active stretch (mean = 10.2 degrees). Both stretch groups' knee joint range of motion improved significantly (p < .05) more than the control group. We conclude that 6 weeks of nonballistic, repetitive active knee extensions (30 repetitions, twice daily) performed in a neural slump sitting position improves hamstring flexibility in uninjured subjects, but is no different compared with static stretching (30 seconds, twice daily).
Role of hyperpronation as a possible risk factor for anterior cruciate ligament injuries.
OBJECTIVE: The purpose of this study was to examine the relationship between hyperpronation and the occurrence of noncontact injury to the anterior cruciate ligament (ACL). DESIGN AND SETTING: Subjects were categorized as either ACL injured (ACLI) or ACL uninjured (ACLU). All ACLI subjects received their injuries from a noncontact mechanism. To justify using the ACLI subjects' uninjured legs as representative of their preinjury state, a t test was used to compare the differences between the left and right foot for the ACLU group on both measurements. Based on the results of the t test, a regression analysis was performed to determine whether group membership could be predicted from navicular drop. All measures were performed in a university athletic training room. SUBJECTS: Fourteen ACLI subjects (age = 21.07 +/- 0.83 yr, ht = 174.81+/-8.29 cm, wt = 72.32+/-13.47 kg) and 14 ACLU subjects (age = 21.14+/-2.03 yr, ht = 177.35+/-11.31 cm, wt = 72.99+/-14.81 kg) participated. MEASUREMENTS: Hyperpronation was assessed via the navicular drop test and the calcaneal stance test. RESULTS: No significant difference (p > .05) between feet for the navicular drop test was found. However, there was a significant difference (p < .05) between feet for the calcaneal stance test, and, thus, this measure was not used in the regression analysis. Using the navicular drop score, the regression analysis was unable to predict group membership. CONCLUSIONS: Hyperpronation as measured by the navicular drop test was not a predictor of ACL injury, and, thus, may not be a predisposing factor to noncontact ACL injuries.
Effect of unilateral functional instability of the ankle on postural sway and inversion and eversion strength.
OBJECTIVE: The purpose of this study was to determine if individuals with unilateral functional ankle instability had decreased ability to maintain postural sway, as well as decreased isokinetic eccentric strength of ankle evertors and invertors. DESIGN AND SETTING: SUBJECTS WITH NO PREVIOUS HISTORY OF ANKLE INJURY WERE COMPARED WITH SUBJECTS WITH FUNCTIONAL ANKLE INSTABILITY ON THE FOLLOWING TESTS: isokinetic eccentric inversion and eversion strength and measures of single-limb postural sway. SUBJECTS: EIGHTEEN SUBJECTS PARTICIPATED IN THIS STUDY: 9 subjects in the functional instability (FI) group (age = 22.89 +/- 3.18 yr, ht = 181 +/- 6.0 cm, wt = 80.25 +/- 12.2 kg) and 9 noninjured (NI) controls (age = 26.22 +/- 2.34 yr, ht = 170 +/- 10.0 cm, wt = 65.08 +/- 12.03 kg). MEASUREMENTS: Subjects performed postural sway assessment on a balance system under static and dynamic conditions. Ankle inversion and eversion eccentric strength were evaluated at 90 degrees /sec using an isokinetic dynamometer. Additionally, we assessed the degree of mechanical instability in the FI group with a series of stress radiographs. RESULTS: No significant differences in single-limb postural sway measures or in eversion strength between limbs in the FI group or between groups were found. A significant group-by-limb interaction was present in inversion peak torque; however, post hoc testing revealed the only difference to be between the dominant and nondominant limbs of the NI group. CONCLUSIONS: Postural sway and inversion and eversion eccentric peak torque are not affected by functional instability of the ankle. Alternate methods of postural sway assessment and ankle strength measurement are discussed as possible areas for future study.
Effect of orthotics on postural sway following inversion ankle sprain.
Orthotic devices have been shown to successfully modify selected aspects of lower extremity mechanics and enhance foot stability during the support phase of running. It was hypothesized that orthotic intervention would relieve excessive strain on the ankle ligaments and reduce postural sway, especially in subjects with acute ankle sprains. The primary purpose of this study was to determine if orthotics would reduce postural sway in injured and uninjured subjects. Thirteen subjects with acute inversion ankle sprain and 12 uninjured subjects were assessed for postural sway on the Balance System under two treatment conditions (orthotic and nonorthotic) and four platform movements. A three-factor repeated measures analysis of variance revealed a significant group X treatment interaction, suggesting that postural sway with orthotic intervention improved significantly more in injured subjects than in uninjured subjects. A significant platform movement X treatment interaction, furthermore, revealed that postural sway for the four movement conditions was dependent upon treatment (orthotic vs. no orthotic). Tukey post hoc analysis revealed that orthotic intervention significantly reduced postural sway when the platform moved in the medial/lateral plane and inversion/eversion plane. This research suggests that custom-fit orthotics may restrict undesirable motion at the foot and ankle and enhance joint mechanoreceptors to detect perturbations and provide structural support for detecting and controlling postural sway in ankle-injured subjects.
Functional performance following an ice immersion to the lower extremity.
Cryotherapy is a widely accepted component of treatment for acute injuries. It has recently re-entered the later stages of rehabilitation as a contributing modality. Cryotherapy's depressive effects on the body's physiological systems have generated concern among many health care practitioners about its effect on motor activity. This study examined the effects of an ice immersion on three functional performance tests: the shuttle run, the 6-m hop test, and the single-leg vertical jump. Twenty volunteers from Division III soccer and football teams who had not sustained an injury to the lower extremity within the past 6 months were randomly assigned to either an experimental or control group. Subjects in the experimental group performed three trials of each functional performance test before and after the application of a 20-minute ice immersion (13 degrees C) to the lower leg. Subjects in the comparison group followed the same procedure except that a 20-minute resting period replaced the cold treatment. A mixed design analysis of variance was used to analyze the data. Vertical jump scores decreased in the experimental group (41.4 +/- 6.8 cm to 39.3 +/- 6.1 cm) but not in the control group (45.2 +/- 5.5 cm to 45.7 +/- 5.9 cm) as a result of the treatment. Shuttle run times decreased in the experimental group (6.5 +/- 0.3 seconds to 6.7 +/- 0.4 seconds) but not in the control group (6.8 +/- 0.4 seconds to 6.8 +/- 0.4 seconds). Six-meter hop test values were not affected. We suggest that clinicians should carefully consider the immediate effects, potentially, of cold on motor activity.
Effect of prophylactic knee bracing on balance and joint position sense.
Prophylactic knee braces are designed to prevent and reduce the severity of ligamentous injuries to the knee. Conflicting evidence is reported concerning their efficacy. The purpose of this study was to determine the effect of prophylactic knee bracing on the proprioceptive parameters of balance and joint position sense. Active and passive joint position sense were assessed using the Cybex II + Isokinetic Dynamometer (Cybex Division of Lumex, Inc, Ronkonkoma, NY). Sway index and center of balance were assessed using the Chattecx Dynamic Balance System (Chattanooga Group, Hixson, TN). Thirty-six male subjects were measured with and without prophylactic knee braces. Joint position sense was measured in degrees of error from four preselected target angles. Sway index and center of balance measures were recorded in centimeters under the following platform conditions: stable, plantar flexion/dorsiflexion, and inversion/eversion. Separate repeated measures ANOVAs were performed to determine if there were differences between the braced and unbraced conditions for center of balance, sway index, and joint position sense. Center of balance with the platform moving in a dorsi/plantar flexion direction was improved while wearing the knee braces. In addition, differences in both center of balance and sway were recorded across the three platform conditions with and without knee bracing. Bracing did not affect joint position sense. The results of this study suggest that prophylactic knee braces have very little impact on proprioceptive feedback mechanisms.
1994 athletic trainer employment and salary characteristics.
OBJECTIVE: THE PURPOSE OF THIS STUDY WAS TO DETERMINE: 1) demographics and professional credentials of recently hired athletic trainers, 2) the association between these characteristics and the high school, clinical, and collegiate setting, and 3) which of these factors best predicted salary. DESIGN AND SETTING: A survey was sent to all prospective employers. Of the 472 surveys sent, 282 (60%) were returned. SUBJECTS: Prospective employers who were listed on the NATA job vacancy notices from January 1, 1994 to October 1, 1994. MEASUREMENTS: Employers selected a job description for their position opening and indicated the characteristics of the people they hired. The job descriptions were placed into three categories. A chi-square analysis was used to determine the degree of association between applicant characteristics and job descriptions. Employee characteristics were coded and a stepwise multiple regression analysis was performed to determined which of the characteristics best predicted salary. Analyses of variance were performed to determine differences among the three practice settings and as follow-up analyses to the multiple regression. An analysis of variance was also performed to compare salaries based on job description and teaching responsibilities. RESULTS: No association was found between the employment setting and gender, ethnicity, marital status, educational route, physical therapy, credential, or EMT certification. There was an association between the CPR instructor's credential and employment setting and between highest degree attained and employment setting. CONCLUSIONS: The results suggest that these factors were most closely associated with employment in the collegiate setting. With regard to salary, it was determined that a doctoral degree, a master's degree, and marital status were the best predictors of salary.
Hot and cold whirlpool treatments and knee joint laxity.
OBJECTIVE: To examine the influence of clinical applications of heat and cold on arthrometric laxity measurements of the knee. DESIGN AND SETTING: The knee joint was submersed 4 inches above the patella in hot and cold whirlpools containing water of 40 degrees C and 15 degrees C for 20 minutes. A control was also performed to provide a neutral temperature comparison group. SUBJECTS: Eight males and 7 females with no history of knee injury. MEASUREMENTS: The knee was maintained at 20 degrees flexion and tibial rotation at either 15 degrees of internal rotation, 15 degrees of external rotation, or a neutral measurement with a modified KT-1000 knee arthrometer equipped with an LCCB-50 strain gauge that allowed for the digital display of the applied distraction forces. Order of testing was counterbalanced. Subjects underwent each condition once, with each trial on separate days. Two 2-factor repeated measure analyses of variance were performed to test effects of temperature on knee laxity for the dependent measure (laxity at 89N and at maximal displacement forces). RESULTS: There was no thermal effect on displacement at 89N nor at maximal distraction (p > .05). A difference was found with respect to test position, with external rotation showing a greater displacement than internal rotation (p < .05). CONCLUSIONS: There was no evidence that hot or cold whirlpool treatments alter knee laxity as assessed with the KT-1000. Rotation of the tibia does affect the magnitude of displacement of the knee. Further research is needed to determine if these findings can be applied to ACL-deficient or ACL-reconstructed knees.
Effect of mild head injury on postural stability in athletes.
OBJECTIVE: Athletic trainers and team physicians are often faced with the dilemma of when to return athletes to participation following mild head injury. Unfortunately, clinicians rarely have quantitative information on which to base their decisions. The purpose of this investigation was to identify postural stability changes in athletes with acute mild head injury. DESIGN AND SETTING: High school and college male athletes were prescreened for postural stability before the start of their season. Subjects suffering injury during the season returned for testing on days 1, 3, 5, and 10 following injury, and 1 month postseason. Control subjects were selected for comparisons. SUBJECTS: Ten prescreened subjects (age = 17.4 +/- 2.2 yr; ht = 183.8 + 8.1 cm; wt = 87.7 + 17.3 kg) returned for testing following an injury. Ten matched control subjects (age = 18.6 +/- 2.6 yr; ht = 185.7 +/- 6.7 cm; wt = 84.5 +/- 19.5 kg) were selected for comparisons. Additionally, nine subjects (eight male and one female) (age = 19.9 +/- 4.2 yr; ht = 182.3 + 10.9 cm; wt = 89.6 +/- 25.2 kg) who had sustained a mild head injury from other varsity sports teams were recruited. Nine matched controls (age = 22.1 +/- 3.3 yr; ht = 181.0 +/- 9.9 cm; wt = 84.9 +/- 25.6 kg) were again utilized. MEASUREMENTS: Sway index and center of balance were measured using the Chattecx Balance System during three eye conditions and three surface conditions for all subjects. RESULTS: Repeated measures analyses of variance (ANOVA) for each prescreened subject's sway index revealed significant differences between injured subjects and control subjects on day 1 postinjury as compared with the prescreening and/or subsequent tests. The analysis for sway index and center of balance inclusive of all 19 subjects with mild head injury and all 19 control subjects demonstrated increased postural sway compared with control subjects on day 1 postinjury during all plafform conditions, and on day 3 during the foam platform condition. The analysis for center of balance using the same subjects revealed that injured subjects maintained their center of balance farther away on day 1 postinjury compared with subsequent tests (p < .05). CONCLUSIONS: These findings suggest that computerized dynamic posturography is a useful tool in objectively assessing postural stability in subjects with mild head injuries. Subjects with mild head injury appear to demonstrate impaired postural stability 1 to 3 days following injury. This information should aid clinicians in determining when an athlete can safely return to participation.
Effect of running on anterior knee laxity in collegiate-level female athletes after anterior cruciate ligament reconstruction.
Agility running activities are commonly used in the latter stages of rehabilitation for anterior cruciate ligament (ACL) reconstruction. However, the effects of agility running on anterior knee laxity in these patients have not been examined. The purpose of this study was to examine changes in anterior knee laxity before and after 30 minutes of agility running exercise. Subjects (N = 9) were female athletes (mean age = 20.1 +/- 1.5 years; height = 171.7 +/- 10.4 cm; weight = 65.7 +/- 8.6 kg) with unilateral ACL reconstruction (central 1/3 patella tendon graft, postoperation range = 9-52 months, mean = 24.2 months). Measurements were made at 20 degrees and 90 degrees of knee flexion bilaterally with KT-1000 arthrometry (MEDmetric, San Diego, CA) and recorded in millimeters of displacement. Data were analyzed with an analysis of variance (ANOVA) with repeated measures (p < 0.05). Results showed no statistical differences between the ACL-reconstructed knee and the normal knee at 20 degrees and 90 degrees knee flexion. The authors conclude that the central 1/3 patella tendon graft performs comparable to the normal knee when stressed with agility running exercise; therefore, agility exercise is an appropriate, safe, short-term activity.
Prediction of Academic Achievement in an NATA-Approved Graduate Athletic Training Education Program.
The Purpose of this investigation was to determine which information used in the applicant selection process would best predict the final grade point average of students in a National Athletic Trainers Association (NATA) graduate athletic training education program. The criterion variable used was the graduate grade-point average (GPAg) calculated at the completion of the program of study. The predictor variables included: 1) Graduate Record Examination-Quantitative (GRE-Q) scores; and 2) Graduate Record Examination-Verbal (GRE-V) scores, 3) preadmission grade point average (GPAp), 4) total athletic training hours (hours), and 5) curriculum or internship undergraduate athletic training education (program). Data from 55 graduate athletic training students during a 5-year period were evaluated. Stepwise multiple regression analysis indicated that GPAp was a significant predictor of GPAg, accounting for 34% of the variance. GRE-Q, GRE-V, hours, and program did not significantly contribute individually or in combination to the prediction of GPAg. The results of this investigation suggest that, of the variables examined, GPAp is the best predictor of academic success in an NATA-approved graduate athletic training education program.
Intertester reliability of assessing postural sway using the chattecx balance system.
In this study, we examined intertester reliability of dynamic and static balance using the Chattecx Dynamic Balance System. Ten female and two male subjects were randomly assigned to two testers and completed ten, 10-second preprogrammed double- and single-leg test conditions. Balance was measured as postural sway in centimeters by the Chattecx Dynamic Balance System. Static balance consisted of the platform remaining stable, whereas dynamic balance consisted of the platform tilting in an anterior and posterior direction during testing. The protocols and average postural sway values were:1. Double-Leg Static Eyes Open ([unk] = .28 cm)2. Double-Leg Static Eyes Closed ([unk] = .37 cm)3. Double-Leg Dynamic Eyes Open ([unk] = .86 cm)4. Double-Leg Dynamic Eyes Closed ([unk] = 1.72 cm)5. Single-Leg Static Dominant Eyes Open ([unk] = .99 cm)6. Single-Leg Static Dominant Eyes Closed ([unk] = 1.70 cm)7. Single-Leg Static Nondominant Eyes Open ([unk] = .65 cm)8. Single-Leg Static Nondominant Eyes Closed ([unk] = 1.48 cm)9. Single-Leg Dynamic Dominant Eyes Open ([unk] = .99cm)10. Single-Leg Dynamic Nondominant Eyes Open ([unk] = .91 cm).The mean values of postural sway ranged from .28 cm to 1.72 cm for double-leg stance measures and from .65 cm to 1.70 cm for the single-leg stance measures. The intraclass correlations (ICCs)(2,1) ranged from poor to excellent (ICCs = .06 to .90) and the standard error of measurement (SEM) ranged from .06 to .34 for the 10 trials. We feel that variability exists between subjects and/or testers between trials. The wide range of reliability values suggests that further research should determine both intratester and intertester reliability using a variety of protocols for assessment of static and dynamic balance.