King-Devick Test in Wheelchair Sports: Identifying Normative Values and Effects of Exertion on Outcomes.

OBJECTIVE: To establish normative baseline values on the King-Devick (KD) Test for contact wheelchair sport participants. The secondary purpose was to examine the effect of physical exertion on test score. DESIGN: Quasiexperimental. SETTING: Competitive disability sport venues before practices or games. PARTICIPANTS: One-hundred 43 wheelchair rugby or wheelchair basketball (WBB) players completed the study. Participants were predominantly men (87.5%) and played WBB (84%). INTERVENTION: 30-m wheelchair sprint test to fatigue. MAIN OUTCOME MEASURE: King-Devick Baseline Score. RESULTS: Mean KD baseline score was 59.16 ± 15.56 seconds with significant differences ( P < 0.05) identified by sport and impairment type, but not sex. Athletes with spina bifida and cerebral palsy had significantly higher mean baseline KD times than athletes with spinal cord injury. KD scores improved by 3.5% in athletes who reported "light" to "somewhat hard" exertion (RPE = 13). In a subset of athletes who performed sprints until an RPE of 18 was reached, 8 of 12 players (66.7%) demonstrated an improvement in KD score; however, large increases by a few participants caused the noticeable change. CONCLUSIONS: Normative values for wheelchair contact sport athletes are meaningfully slower than able-bodied sports participants. KD score improved with exertion with the greater improvement after moderate-intensity compared with vigorous-intensity exercise. These findings can be applied clinically to monitor athlete safety.

Four-Week Ankle-Rehabilitation Programs in Adolescent Athletes With Chronic Ankle Instability.

CONTEXT: Researchers have shown that rehabilitation programs incorporating resistance-band and balance-board exercises are effective for improving clinical measures of function and patient-reported outcomes in individuals with chronic ankle instability (CAI). However, whether combining the 2 exercises increases improvement is unknown. OBJECTIVE: To determine the effectiveness of 3 rehabilitation programs on clinical measures of balance and self-reported function in adolescent patients with CAI. DESIGN: Randomized controlled clinical trial (Trail Registration Number: ClinicalTrails.gov: NCT03447652). SETTING: High school athletic training facilities. PATIENTS OR OTHER PARTICIPANTS: Forty-three patients with CAI (age = 16.37 ± 1.00 years, height = 171.75 ± 12.05 cm, mass = 69.38 ± 18.36 kg) were block randomized into 4 rehabilitation groups. INTERVENTION(S): Protocols were completed 3 times per week for 4 weeks. The resistance-band group performed 3 sets of 10 repetitions of ankle plantar flexion, dorsiflexion, inversion, and eversion with a resistance band. The Biomechanical Ankle Platform System group performed 5 trials of clockwise and counterclockwise rotations, changing direction every 10 seconds during each 40-second trial. The combination group completed resistance-band and Biomechanical Ankle Platform System programs during each session. The control group did not perform any exercises. MAIN OUTCOME MEASURE(S): Variables were assessed before and after the intervention: time-in-balance test, foot-lift test, Star Excursion Balance Test, side-hop test, figure-8 hop test, Foot and Ankle Ability Measure, and Cumberland Ankle Instability Tool. We conducted 4 separate multivariate repeated-measures analyses of variance, followed by univariate analyses for any findings that were different. RESULTS: Using the time-in-balance test, foot-lift test, Star Excursion Balance Test (medial, posteromedial, and posterolateral directions), and figure-8 hop test, we detected improvement for each rehabilitation group compared with the control group (P < .05). However, no intervention group was superior. CONCLUSIONS: All 3 rehabilitation groups demonstrated improvement compared with the control group, yet the evidence was too limited to support a superior intervention. Over a 4-week period, either of the single-task interventions or the combination intervention can be used to combat the residual deficits associated with CAI in an adolescent patient population.

Vestibular Rehabilitation Therapy Improves Perceived Disability Associated With Dizziness Postconcussion.

Clinical Scenario: Every year, millions of people suffer a concussion. A significant portion of these people experience symptoms lasting longer than 10 days and are diagnosed with postconcussion syndrome. Dizziness is the second most reported symptom associated with a concussion and may be a predictor of prolonged recovery. Clinicians are beginning to incorporate vestibular rehabilitation therapy (VRT) in their postconcussion treatment plan, in order to address the dysfunctional inner ear structures that could be causing this dizziness. Focused Clinical Question: Can VRT help postconcussion syndrome patients experiencing prolonged dizziness by improving their perceived disability? Summary of Key Findings: Three studies were included: 1 randomized control trial, 1 retrospective chart review, and 1 exploratory study. The randomized control trial compared cervical spine therapy alone to cervical spine therapy in conjunction with VRT to obtain medical clearance for sport. The chart review explored VRT as a treatment for reducing dizziness and improving balance and gait dysfunction. The exploratory study implemented VRT in conjunction with light aerobic exercise to improve perceived disability associated with dizziness postconcussion. All 3 studies found statistically significant decreases (improvements) in Dizziness Handicap Index scores. Clinical Bottom Line: There is preliminary evidence suggesting that VRT can improve perceived disability in patients with postconcussion syndrome experiencing prolonged dizziness. There is a decrease (improvement) in Dizziness Handicap Index scores across all 3 studies. VRT is a relatively safe treatment option, with no adverse reactions or case reports. Strength of Recommendation: There is level 2 and level 3 evidence supporting the use of VRT to treat patients suffering from dizziness postconcussion.

Establishing the Minimal Clinical Important Difference and Minimal Detectable Change for the Cumberland Ankle Instability Tool.

OBJECTIVE: To establish the minimal detectable change (MDC) and minimal clinically important difference (MCID) for the Cumberland Ankle Instability Tool (CAIT) in a population with chronic ankle instability (CAI). DESIGN: Experimental cohort. SETTING: Laboratory. PARTICIPANTS: A convenience sample of individuals with CAI (N=50; 12 men; 38 women; episodes of giving way, 5.84±12.54mo). CAI inclusion criteria included a history of an ankle sprain, recurrent episodes of giving way, and a CAIT score ≤25. INTERVENTIONS: Participants completed demographic information, an injury history questionnaire, and the CAIT. Participants then either participated in 4 weeks of wobble board balance training, resistance tubing strength training, or no intervention. After 4 weeks, participants recompleted the CAIT and recorded their global rating of change (GRC). MAIN OUTCOME MEASURES: Dependent variables were pre- and postintervention scores on the CAIT and postintervention GRC. The MDC with 95% confidence interval was calculated. A receiver operating characteristic (ROC) curve identified the optimal CAIT cut point (MCID) between improved and unimproved individuals on the basis of their GRC. The area under the curve was used to identify a significant ROC curve (α=.05). RESULTS: The average CAIT score preintervention was 16.8±5.6, and postintervention, it was 20.0±5.2. Thirty-one participants (62%) rated themselves as improved on the GRC scale, whereas 19 (38%) were not improved. The ROC curve was significant (area under the curve, .797; P=.001), indicating that the CAIT change score significantly predicted clinical status. The MDC was 3.08, and the MCID was ≥3 points. CONCLUSIONS: The CAIT has an MDC and MCID of ≥3 points. When CAIT scores are used to assess patient change over time, these scores should be used as a minimum threshold to indicate detectable and clinically meaningful improvement.

Effects of a 4-Week Biomechanical Ankle Platform System Protocol on Balance in High School Athletes With Chronic Ankle Instability.

CONTEXT: Chronic ankle instability (CAI) describes the residual symptoms present after repetitive ankle sprains. Current rehabilitation programs in the high school population focus on a multistation approach or general lower-extremity injury-prevention program. Specific rehabilitation techniques for CAI have not been established. OBJECTIVE: To determine the effectiveness of a 4-wk biomechanical ankle platform system (BAPS) board protocol on the balance of high school athletes with CAI. DESIGN: Randomized control trial. SETTING: Athletic training facility. PATIENTS: Twenty-two high school athletes with "giving way" and a history of ankle sprains (ie, CAI) were randomized into a rehabilitation (REH) (166.23 ± 0.93 cm, 67.0 ± 9.47 kg, 16.45 ± 0.93 y) or control (CON) (173.86 ± 8.88 cm, 84.51 ± 21.28 kg, 16.55 ± 1.29 y) group. INTERVENTIONS: After baseline measures, the REH group completed a progressive BAPS rehabilitation program (3 times/wk for 4 wk), whereas the CON group had no intervention. Each session consisted of 5 trials of clockwise/counterclockwise rotations changing direction every 10 s during each 40-s trial. After 4 wk, baseline measurements were repeated. MAIN OUTCOME MEASURES: Dependent measures included longest time (time-in-balance test), average number of errors (foot lift test), average reach distance (cm) normalized to leg length for each reach direction (Star Excursion Balance Test [SEBT]), and fastest time (side hop test [SHT]). RESULTS: Significant group-by-time interactions were found for TIB (F1,20 = 9.89, P = .005), FLT (F1,20 = 41.18, P < .001), SEBT-anteromedial (F1,20 = 5.34, P = .032), SEBT-medial (F1,20 = 7.51, P = .013), SEBT-posteromedial (F1,20 = 12.84, P = .002), and SHT (F1,20 = 7.50, P = .013). Post hoc testing showed that the REH group improved performance on all measures at posttest, whereas the CON group did not. CONCLUSION: A 4-wk BAPS rehabilitation protocol improved balance in high school athletes suffering from CAI. These results can allow clinicians to rehabilitate in a focused manner by using 1 rehabilitation tool that allows benefits to be accomplished in a shorter time.

A Randomized Controlled Trial Comparing Rehabilitation Efficacy in Chronic Ankle Instability.

CONTEXT: There is minimal patient-oriented evidence regarding the effectiveness of interventions targeted to reduce symptoms associated with chronic ankle instability (CAI). In addition, clinicians aiming to prioritize care by implementing only the most effective components of a rehabilitative program have very little evidence on comparative efficacy. OBJECTIVE: To assess the comparative efficacy of 2 common ankle rehabilitation techniques (wobble-board [WB] balance training and ankle strengthening using resistance tubing [RT]) using patient-oriented outcomes. DESIGN: Randomized controlled trial. SETTING: Laboratory. PATIENTS: 40 patients with CAI randomized into 2 treatment groups: RT and WB. CAI inclusion criteria included a history of an ankle sprain, recurrent "giving way," and a Cumberland Ankle Instability Tool (CAIT) score ≤25. INTERVENTIONS: Participants completed 5 clinician-oriented tests (foot-lift test, time-in-balance, Star Excursion Balance Test, figure-of-8 hop, and side-hop) and 5 patient-oriented questionnaires (CAIT, Foot and Ankle Ability Measure [FAAM], Activities of Daily Living [ADL] and FAAM Sport scale, Short-Form 36 [SF-36], and Global Rating of Function [GRF]). After baseline testing, participants completed 12 sessions over 4 wk of graduated WB or RT exercise, then repeated baseline tests. MAIN OUTCOME MEASURES: For each patient- and clinician-oriented test, separate 2 × 2 RMANOVAs analyzed differences between groups over time (alpha set at P = .05). RESULTS: There was a significant interaction between group and time for the FAAM-ADL (P = .04). Specifically, the WB group improved postintervention (P < .001) whereas the RT group remained the same (P = .29). There were no other significant interactions or significant differences between groups (all P > .05). There were significant improvements postintervention for the CAIT, FAAM-Sport, GRF, SF-36, and all 5 clinician-oriented tests (all P < .001). CONCLUSIONS: A single-exercise 4-wk intervention can improve patient- and clinician-oriented outcomes in individuals with CAI. Limited evidence indicates that WB training was more effective than RT. LEVEL OF EVIDENCE: Therapy, level 1b.

Patient-Reported Efficacy 6 Months After a 4-Week Rehabilitation Intervention in Individuals With Chronic Ankle Instability.

OBJECTIVE: To track the patient-reported efficacy of a 4-wk intervention (wobble board [WB] or resistance tubing [RT]) in decreasing symptoms of chronic ankle instability (CAI) at 6 mo postintervention (6PI) as compared with immediately postintervention (IPI). DESIGN: Randomized controlled trial. PARTICIPANTS: Fourteen of 21 participants (66.7%) responded to an electronic 6-m follow-up questionnaire (age 19.6 ± 0.9 y, height 1.63 ± 0.18 m, weight 70.5 ± 16.3 kg; 2 male, 12 female; 5 WB, 9 RT). All participants met CAI criteria at enrollment, including a history of ankle sprain and recurrent episodes of giving way. INTERVENTIONS: Participants completed either RT or WB protocols, both 12 sessions over 4 wk of progressive exercise. WB sessions consisted of five 40-s sets of clockwise and counterclockwise rotations. RT sessions consisted of 30 contractions against resistance tubing in each of 4 ankle directions. MAIN OUTCOME MEASUREMENTS: Patient-reported symptoms of "giving way" preintervention and at 6PI, global rating of change (GRC) frequencies at IPI and 6PI, and resprains at 6PI were reported descriptively. Changes in global rating of function (GRF) and giving way were compared using Wilcoxon tests, while GRC was compared with Fisher exact test. RESULTS: All participants reported giving way preintervention, only 57.1% reported giving way at 6PI. Resprains occurred in 21.4% of participants. Giving-way frequency (P = .017), but not GRF or GRC (P > .05), was significantly different at IPI vs 6PI. CONCLUSIONS: Simple 4-wk interventions maintained some but not all improvements at 6PI. At least 42.9% of participants would no longer meet the current study's CAI inclusion criteria due to a reduction in giving way.

Wobble Board Rehabilitation for Improving Balance in Ankles With Chronic Instability.

OBJECTIVE: To quantify improvements in clinical impairments using a wobble board rehabilitation protocol for chronic ankle instability (CAI). DESIGN: Prospective randomized controlled trial. SETTING: Laboratory. PATIENTS: Thirty-four participants with "giving way" and history of ankle sprains were randomly assigned to a rehabilitation group (REH) (170.22 ± 8.71 cm; 75.57 ± 13.55 kg; 22.94 ± 2.77 years) or control group (CON) (168.57 ± 9.81 cm; 77.19 ± 19.93 kg; 23.18 ± 3.64 years). INTERVENTIONS: Four weeks with no intervention for CON or wobble board rehabilitation for REH, consisting of 3 sessions per week of 5 repetitions. MAIN OUTCOME MEASURES: Dependent variables were preintervention and postintervention score on foot lift test (average number of errors), Time-in-Balance Test (TBT) (longest time), Star Excursion Balance Test (SEBT)-anteromedial, medial, and posteromedial (average reach distance normalized to leg length), side hop test (fastest time), and figure-of-eight hop test (fastest time). RESULTS: Main effects for time were significant for all measures (P < 0.05); but main effects for groups were not (P > 0.05) except for SEBT-anteromedial reach direction. Significant interactions were found for all dependent measures (P < 0.05) except for TBT (P > 0.05). Post hoc testing of significant interactions showed REH improved performance at posttest, whereas CON did not. CONCLUSIONS: These findings demonstrate that a single intervention using a wobble board improved static and dynamic balance deficits associated with CAI. CLINICAL RELEVANCE: This approach provides a potentially more economical, time efficient, and space efficient means of improving clinical outcome measures associated with CAI in patients who are physically active.

Noise-Enhanced Eversion Force Sense in Ankles With or Without Functional Instability.

CONTEXT: Force sense impairments are associated with functional ankle instability. Stochastic resonance stimulation (SRS) may have implications for correcting these force sense deficits. OBJECTIVE: To determine if SRS improved force sense. DESIGN: Case-control study. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Twelve people with functional ankle instability (age = 23 ± 3 years, height = 174 ± 8 cm, mass = 69 ± 10 kg) and 12 people with stable ankles (age = 22 ± 2 years, height = 170 ± 7 cm, mass = 64 ± 10 kg). INTERVENTION(S): The eversion force sense protocol required participants to reproduce a targeted muscle tension (10% of maximum voluntary isometric contraction). This protocol was assessed under SRSon and SRSoff (control) conditions. During SRSon, random subsensory mechanical noise was applied to the lower leg at a customized optimal intensity for each participant. MAIN OUTCOME MEASURE(S): Constant error, absolute error, and variable error measures quantified accuracy, overall performance, and consistency of force reproduction, respectively. RESULTS: With SRS, we observed main effects for force sense absolute error (SRSoff = 1.01 ± 0.67 N, SRSon = 0.69 ± 0.42 N) and variable error (SRSoff = 1.11 ± 0.64 N, SRSon = 0.78 ± 0.56 N) (P < .05). No other main effects or treatment-by-group interactions were found (P > .05). CONCLUSIONS: Although SRS reduced the overall magnitude (absolute error) and variability (variable error) of force sense errors, it had no effect on the directionality (constant error). Clinically, SRS may enhance muscle tension ability, which could have treatment implications for ankle stability.

Recalibration and validation of the Cumberland Ankle Instability Tool cutoff score for individuals with chronic ankle instability.

OBJECTIVE: To independently recalibrate and revalidate the Cumberland Ankle Instability Tool (CAIT) cutoff score for discriminating individuals with and without chronic ankle instability (CAI). There are concerns the original cutoff score (≤27) may be suboptimal for use in the CAI population. DESIGN: Case control. SETTING: Research laboratory. PARTICIPANTS: Two independent datasets were used (total N=200). Dataset 1 included 61 individuals with a history of ≥1 ankle sprain and ≥2 episodes of giving way in the last year (CAI group) and 57 participants with no history of ankle sprain or instability in their lifetime (uninjured group). Dataset 2 included 27 uninjured participants, 29 participants with CAI, and 26 individuals with a history of a single ankle sprain and no subsequent instability (copers). INTERVENTIONS: All participants completed the CAIT during a single session. In dataset 1, a receiver operating characteristic (ROC) curve was calculated using the CAIT score and group membership as test variables. The ideal cutoff score was identified using the Youden index. The recalibrated cutoff score was validated in dataset 2 using the ROC analysis and clinimetric characteristics. MAIN OUTCOME MEASURES: CAIT cutoff score and clinimetrics. RESULTS: In dataset 1, the optimal cutoff score was ≤25, which is lower than previously reported. In dataset 2, the recalibrated cutoff score demonstrated a sensitivity of 96.6%, specificity of 86.8%, positive likelihood ratio of 7.318, and negative likelihood ratio of .039. There were 7 false positives and 1 false negative. CONCLUSIONS: The recalibrated CAIT score demonstrated very good clinimetric properties; all properties improved compared with the original cutoff score. Clinicians using the CAIT should use the recalibrated cutoff score to maximize test characteristics. Caution should be taken with copers, who had a high rate of false positives.

Postural-stability tests that identify individuals with chronic ankle instability.

CONTEXT: Chronic ankle instability (CAI) is characterized by repeated ankle sprains, which have been linked to postural instability. Therefore, it is important for clinicians to identify individuals with CAI who can benefit from rehabilitation. OBJECTIVE: To assess the likelihood that CAI participants will exhibit impaired postural stability and that healthy control participants will exhibit better test performance values. DESIGN: Case-control study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: People with CAI (n = 17, age = 23 ± 4 years, height = 168 ± 9 cm, weight = 68 ± 12 kg) who reported ankle "giving-way" sensations and healthy volunteers (n = 17, age = 23 ± 3 years, height = 168 ± 8 cm, weight = 66 ± 12 kg). INTERVENTION(S): Participants performed 7 balance tests: Balance Error Scoring System (BESS), time in balance, foot lift, single-legged stance on a force plate, Star Excursion Balance Test, side hop, and figure-of-8 hop. MAIN OUTCOME MEASURE(S): Balance was quantified with errors (score) for the BESS, length of time balancing (seconds) for time-in-balance test, frequency of foot lifts (score) for foot-lift test, velocity (cm/s) for all center-of-pressure velocity measures, excursion (cm) for center-of-pressure excursion measures, area (cm2) for 95% confidence ellipse center-of-pressure area and center-of-pressure rectangular area, time (seconds) for anterior-posterior and medial-lateral time-to-boundary (TTB) measures, distance reached (cm) for Star Excursion Balance Test, and time (seconds) to complete side-hop and figure-of-8 hop tests. We calculated area-under-the-curve values and cutoff scores and used the odds ratio to determine if those with and without CAI could be distinguished using cutoff scores. RESULTS: We found significant area-under-the-curve values for 4 static noninstrumented measures, 3 force-plate measures, and 3 functional measures. Significant cutoff scores were noted for the time-in-balance test (≤25.89 seconds), foot-lift test (≥5), single-legged stance on the firm surface (≥3 errors) and total (≥14 errors) on the BESS, center-of-pressure resultant velocity (≥1.56 cm/s), standard deviations for medial-lateral (≤1.56 seconds) time-to-boundary and anterior-posterior (≤3.78 seconds) time-to-boundary test, posteromedial direction on the Star Excursion Balance Test (≤0.91), side-hop test (≥12.88 seconds), and figure-of-8 hop test (≥17.36 seconds). CONCLUSIONS: Clinicians can use any of the 10 significant measures with their associated cutoff scores to identify those who could benefit from rehabilitation that reestablishes postural stability.

Customized noise-stimulation intensity for bipedal stability and unipedal balance deficits associated with functional ankle instability.

CONTEXT: Stochastic resonance stimulation (SRS) administered at an optimal intensity could maximize the effects of treatment on balance. OBJECTIVE: To determine if a customized optimal SRS intensity is better than a traditional SRS protocol (applying the same percentage sensory threshold intensity for all participants) for improving double- and single-legged balance in participants with or without functional ankle instability (FAI). DESIGN: Case-control study with an embedded crossover design. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Twelve healthy participants (6 men, 6 women; age = 22 ± 2 years, height = 170 ± 7 cm, mass = 64 ± 10 kg) and 12 participants (6 men, 6 women; age = 23 ± 3 years, height = 174 ± 8 cm, mass = 69 ± 10 kg) with FAI. INTERVENTION(S): The SRS optimal intensity level was determined by finding the intensity from 4 experimental intensities at the percentage sensory threshold (25% [SRS25], 50% [SRS50], 75% [SRS75], 90% [SRS90]) that produced the greatest improvement in resultant center-of-pressure velocity (R-COPV) over a control condition (SRS0) during double-legged balance. We examined double- and single-legged balance tests, comparing optimal SRS (SRS(opt1)) and SRS0 using a battery of center-of-pressure measures in the frontal and sagittal planes. MAIN OUTCOME MEASURE(S): Anterior-posterior (A-P) and medial-lateral (M-L) center-of-pressure velocity (COPV) and center-of-pressure excursion (COPE), R-COPV, and 95th percentile center-of-pressure area ellipse (COPA-95). RESULTS: Data were organized into bins that represented optimal (SRS(opt1)), second (SRS(opt2)), third (SRS(opt3)), and fourth (SRS(opt4)) improvement over SRS0. The SRS(opt1) enhanced R-COPV (P ≤ .05) over SRS0 and other SRS conditions (SRS0 = 0.94 ± 0.32 cm/s, SRS(opt1) = 0.80 ± 0.19 cm/s, SRS(opt2) = 0.88 ± 0.24 cm/s, SRS(opt3) = 0.94 ± 0.25 cm/s, SRS(opt4) = 1.00 ± 0.28 cm/s). However, SRS did not improve R-COPV over SRS0 when data were categorized by sensory threshold. Furthermore, SRS(opt1) improved double-legged balance over SRS0 from 11% to 25% in all participants for the center-of-pressure frontal- and sagittal-plane assessments (P ≤ .05). The SRS(opt1) also improved single-legged balance over SRS0 from 10% to 17% in participants with FAI for the center-of-pressure frontal- and sagittal-plane assessments (P ≤ .05). The SRS(opt1) did not improve single-legged balance in participants with stable ankles. CONCLUSIONS: The SRS(opt1) improved double-legged balance and transfers to enhancing single-legged balance deficits associated with FAI.

Balance assessments for predicting functional ankle instability and stable ankles.

A number of instrumented and non-instrumented measures are used to detect balance deficits associated with functional ankle instability (FAI). Determining outcome measures that detect balance deficits associated with FAI might assist clinicians in identifying impairments that may otherwise go undetected with less responsive balance measures. Thus, our objective was to determine the balance measure that best predicted ankle group membership (FAI or stable ankle). Participants included 17 subjects without a history of ankle sprains (168±9 cm, 66±14 kg, 24±5 yr) and 17 subjects with FAI (172±9 cm, 71±11 kg, 22±3 yr). Balance trials were performed without vision and subjects stood on a single leg as motionless as possible for 20s. Balance was quantified with center-of-pressure measures (velocity, area) and error score. Measures were positively correlated with each other (r range: 0.60-0.76). The multifactorial model with all three measures best predicted group membership (F((3,30))=7.20, P=0.001; R(2)=0.42; percent classified correctly=77%), and was followed by the multifactorial model with resultant center-of-pressure velocity and error score (F((2,31))=8.73, P=0.001; R(2)=0.36; percent classified correctly=74%). The resultant center-of-pressure velocity (F((1,32))=13.46, P=0.001; R(2)=0.30; percent classified correctly=74%; unique variance=12.7%) and error score (F((1,32))=12.51, P=0.001; R(2)=0.28; percent classified correctly=71%; unique variance=12.0%) predicted group membership; however, 95th percentile center-of-pressure area ellipse did not (F((1,32))=4.16, P=0.05; R(2)=0.12; percent classified correctly=65%; unique variance=5.8%). A multifactorial single leg balance assessment is best for predicting group membership. COPV is the best single predictor of group membership, but clinicians may use error score to identify deficits associated with FAI if force plates are not available.

Concentric evertor strength differences and functional ankle instability: a meta-analysis.

OBJECTIVE: To determine whether concentric evertor muscle weakness was associated with functional ankle instability (FAI). DATA SOURCES: We conducted an electronic search through November 2007, limited to English, and using PubMed, Pre-CINAHL, CINAHL, and SPORTDiscus. A forward search was conducted using the Science Citation Index on studies from the electronic search. Finally, we conducted a hand search of all selected studies and contacted the respective authors to identify additional studies. We included peer-reviewed manuscripts, dissertations, and theses. STUDY SELECTION: We evaluated the titles and abstracts of studies identified by the electronic searches. Studies were selected by consensus and reviewed only if they included participants with FAI or chronic ankle instability and strength outcomes. Studies were included in the analysis if means and SDs (or other relevant statistical information, such as P values or t values and group n's) were reported for FAI and stable groups (or ankles). DATA EXTRACTION: Data were extracted by the authors independently, cross-checked for accuracy, and limited to outcomes of concentric eversion strength. We rated each study for quality. Outcomes were coded as either fast or slow velocity (ie, equal to or greater than 110 degrees /s or less than 110 degrees /s, respectively). DATA SYNTHESIS: Data included the means, SDs, and group sample sizes (or other appropriate statistical information) for the FAI and uninjured groups (or ankles). The standard difference in the means (SDM) for each outcome was calculated using the pooled SD. We tested individual and overall SDMs using the Z statistic and comparisons between fast and slow velocities using the Q statistic. Our analysis revealed that ankles with FAI were weaker than stable ankles (SDM = 0.224, Z = 4.0, P < .001, 95% confidence interval = 0.115, 0.333). We found no difference between the fast- and slow-velocity SDMs (SDM(Fast) = 0.189, SDM(Slow) = 0.244, Q = 29.9, df = 24, P = .187). Because of the small SDM, this method of measuring ankle strength in the clinical setting may need to be reevaluated.

Ankle instability is associated with balance impairments: a meta-analysis.

PURPOSE: Our primary purpose was to determine whether balance impairments were associated with functional ankle instability (FAI). METHODS: Our literature search consisted of four parts: 1) an electronic search of PubMed, CINAHL, pre-CINAHL, and SPORTDiscus; 2) a forward search of articles selected from the electronic search using the Science Citation Index; 3) a hand search of the previously selected articles; and 4) a direct contact with corresponding authors of the previously selected articles. We initially identified 145 articles and narrowed these to 23 for inclusion in the meta-analysis. Identified outcomes were categorized by measurement units and balance task type (i.e., dynamic or static). Each study was coded based on whether inclusion or exclusion criteria were identified. Our statistical analysis included fixed, random, or mixed effect analyses based on the presence of within study heterogeneity and whether categories were being compared. RESULTS: FAI was associated with poorer balance (standard difference of the mean [SDM] = 0.455, 95% confidence interval = 0.334-0.577, Z = 7.34, P < 0.001), but no difference existed between dynamic and static measure categories (Q = 3.44, P = 0.063). However, there was a significant difference between the dynamic measures (Q = 6.22, P = 0.013) with both time to stabilization and the Star Excursion Balance Test producing significant SDM and between static measures (Q = 13.00, P = 0.012) with the linear, time, velocity, and other measurement categories (but not area) producing significant SDM. Examination of individual outcomes revealed that time in balance and foot lifts produced very large SDM (3.3 and 4.8, respectively). CONCLUSION: FAI is associated with impaired balance. Due to the relatively large effect sizes and simplicity of use of time in balance and foot lifts, we recommend that further research should establish their clinical validity and clinical cutoff scores.

A systematic review of prophylactic braces in the prevention of knee ligament injuries in collegiate football players.

OBJECTIVE: To determine the relative risk reduction associated with prophylactic knee braces in the prevention of knee injuries in collegiate football players. DATA SOURCES: An exhaustive search for original research was performed using the PubMed, SportDiscus, and CINAHL databases from 1970 through November 2006, with the search terms knee brace, knee braces, knee bracing and football, prophylactic brace, and prophylactic knee braces. STUDY SELECTION: Seven studies comparing knee injuries among braced and non-braced collegiate football players were included. Study methods were assessed using the Physiotherapy Evidence Database (PEDro) scale. PEDro scores ranged from 2 to 5. DATA EXTRACTION: The number of participants and frequency of knee injuries were used to calculate the relative risk reduction or increase. DATA SYNTHESIS: We found a relative risk reduction for 3 studies with point estimates of 10% (36% to -26%), 58% (25% to 76%), and 56% (13% to 77%). Four studies demonstrated an increased risk of injury, with point estimates of 17% (19% to -71%), 49% (-31% to -69%), 114% (23% to -492%), and 42% (-18% to -70%). CONCLUSIONS: Data from existing research are inconsistent. Based on a Strength of Recommendation Taxonomy level of evidence of 2 with a grade B recommendation, we cannot conclusively advocate or discourage the use of prophylactic knee braces in the prevention of knee injuries in collegiate football players.