Phillip A. Gribble

Using the Star Excursion Balance Test to Assess Dynamic Postural-Control Deficits and Outcomes in Lower Extremity Injury: A Literature and Systematic Review

CONTEXT A dynamic postural-control task that has gained notoriety in the clinical and research settings is the Star Excursion Balance Test (SEBT). Researchers have suggested that, with appropriate instruction and practice by the individual and normalization of the reaching distances, the SEBT can be used to provide objective measures to differentiate deficits and improvements in dynamic postural-control related to lower extremity injury and induced fatigue, and it has the potential to predict lower extremity injury. However, no one has reviewed this body of literature to determine the usefulness of the SEBT in clinical applications. OBJECTIVE To provide a narrative review of the SEBT and its implementation and the known contributions to task performance and to systematically review the associated literature to address the SEBTs usefulness as a clinical tool for the quantification of dynamic postural-control deficits from lower extremity impairment. DATA SOURCES Databases used to locate peer-reviewed articles published from 1980 and 2010 included Derwent Innovations Index, BIOSIS Previews, Journal Citation Reports, and MEDLINE. STUDY SELECTION The criteria for article selection were (1) The study was original research. (2) The study was written in English. (3) The SEBT was used as a measurement tool. DATA EXTRACTION Specific data extracted from the articles included the ability of the SEBT to differentiate pathologic conditions of the lower extremity, the effects of external influences and interventions, and outcomes from exercise intervention and to predict lower extremity injury. DATA SYNTHESIS More than a decade of research findings has established a comprehensive portfolio of validity for the SEBT, and it should be considered a highly representative, noninstrumented dynamic balance test for physically active individuals. The SEBT has been shown to be a reliable measure and has validity as a dynamic test to predict risk of lower extremity injury, to identify dynamic balance deficits in patients with a variety of lower extremity conditions, and to be responsive to training programs in both healthy people and people with injuries to the lower extremity. Clinicians and researchers should be confident in employing the SEBT as a lower extremity functional test.

Selection criteria for patients with chronic ankle instability in controlled research: a position statement of the international ankle consortium

The International Ankle Consortium is an international community of researchers and clinicians whose primary scholastic purpose is to promote scholarship and dissemination of research-informed knowledge related to pathologies of the ankle complex. The constituents of the International Ankle Consortium and other similar organizations have yet to properly define the clinical phenomenon known as chronic ankle instability (CAI) and its related characteristics for consistent patient recruitment and advancement of research in this area. Although research on CAI and awareness of its impact on society and healthcare systems have grown substantially in the last 2 decades, the inconsistency in participant/patient selection criteria across studies presents a potential obstacle to addressing the problem properly. This major gap within the literature limits the ability to generalize this evidence to the target patient population. Therefore, there is a need to provide standards for patient/participant selection criteria in research focused on CAI, with justifications using the best available evidence.

Support for a Reduction in the Number of Trials Needed for the Star Excursion Balance Test

UNLABELLED Robinson RH, Gribble PA. Support for a reduction in the number of trials needed for the Star Excursion Balance Test. OBJECTIVE To determine the number of trials necessary to achieve stability in excursion distance and stance leg angular displacement for the 8 directions of the Star Excursion Balance Test (SEBT). DESIGN One-way repeated-measures analysis of variance. SETTING Athletic training laboratory. PARTICIPANTS Twenty participants (10 men, 10 women) without any known musculoskeletal injuries or neurologic deficits that could have negatively affected their dynamic balance volunteered for the study. INTERVENTION Participants completed 6 practice and 3 test trials in each of the 8 reach directions of the SEBT. MAIN OUTCOME MEASURES Excursion distances of the reaching leg normalized to leg length and angular displacement at the hip and knee of the stance leg in all 3 planes of movement were determined. RESULTS There were significant increases in excursion distance, hip flexion, and knee flexion for 7, 4, and 5 of the 8 reach directions, respectively. CONCLUSIONS For the majority of the reach directions, maximum excursion distances and stance leg angular displacement values achieved stability within the first 4 practice trials, thus justifying a reduction in the recommended number of practice trials from 6 to 4 and supporting the trend toward simplifying SEBT administration.

Alterations in Knee Kinematics and Dynamic Stability Associated With Chronic Ankle Instability

CONTEXT Chronic ankle instability (CAI) has been previously and separately associated with deficits in dynamic stability and proximal joint neuromuscular alterations, but how the 2 factors relate is unclear. OBJECTIVE To examine the contributions of lower extremity kinematics during an assessment of dynamic stability in participants with CAI. DESIGN Repeated-measures case-control design. SETTING Research laboratory. PATIENTS OR OTHER PARTICIPANTS Thirty-eight volunteers were categorized into groups of those with unilateral CAI (10 men, 9 women; age = 20.3 +/- 2.9 years, height = 1.77 +/- 0.1 m, mass = 76.19 +/- 13.19 kg) and those without (10 men, 9 women; age = 23.1 +/- 3.9 years, height = 1.72 +/- 0.1 m, mass = 72.67 +/- 16.0 kg). INTERVENTION(S) Participants performed 10 jump landings on each limb with a rest period between test limbs. MAIN OUTCOME MEASURE(S) Ankle plantar flexion, knee flexion, and hip flexion were captured with an electromagnetic tracking device at the point of ground impact. Ground reaction force data were used to calculate time to stabilization in the anteroposterior and mediolateral planes. RESULTS For the anteroposterior plane, we found a group-by-side interaction (P = .003), with the injured side of the CAI group demonstrating reduced dynamic stability. For knee flexion, a group main effect (P = .008) showed that the CAI group landed with less knee flexion than the control group. CONCLUSIONS Diminished dynamic stability and decreased knee flexion angle at initial contact were apparent in the CAI group and may play a role in contributing to CAI. This altered kinematic pattern may influence preventive and therapeutic interventions for those with CAI.

Osteoarthritis prevalence following anterior cruciate ligament reconstruction: a systematic review and numbers-needed-to-treat analysis.

OBJECTIVE To determine the prophylactic capability of anterior cruciate ligament (ACL) reconstruction in decreasing the risk of knee osteoarthritis (OA) when compared with ACL-deficient patients, as well as the effect of a concomitant meniscectomy. We also sought to examine the influence of study design, publication date, and graft type as well as the magnitude of change in physical activity from preinjury Tegner scores in both cohorts. DATA SOURCES We searched Web of Science and PubMed databases from 1960 through 2012 with the search terms osteoarthritis, meniscectomy, anterior cruciate ligament, anterior cruciate ligament reconstruction, and anterior cruciate ligament deficient. STUDY SELECTION Articles that reported the prevalence of tibiofemoral or patellofemoral OA based on radiographic assessment were included. We calculated numbers needed to treat and relative risk reduction with associated 95% confidence intervals for 3 groups (1) patients with meniscal and ACL injury, (2) patients with isolated ACL injury, and (3) total patients (groups 1 and 2). DATA EXTRACTION A total of 38 studies met the criteria. Of these, 27 assessed the presence of tibiofemoral osteoarthritis in patients treated with anterior cruciate ligament reconstruction. DATA SYNTHESIS Overall, ACL reconstruction (ACL-R) yielded a numbers needed to treat to harm of 16 with a relative risk increase of 16%. Anterior cruciate ligament reconstruction along with meniscectomy yielded a numbers needed to treat to benefit of 15 and relative risk reduction of 11%. Isolated ACL-R showed a numbers needed to treat to harm of 8 and relative risk increase of 43%. Activity levels were decreased in both ACL-R (d = -0.90; 95% confidence interval = 0.77, 1.13) and ACL-deficient (d = -1.13; 95% confidence interval = 0.96, 1.29) patients after injury. CONCLUSIONS The current literature does not provide substantial evidence to suggest that ACL-R is an adequate intervention to prevent knee osteoarthritis. With regard to osteoarthritis prevalence, the only patients benefiting from ACL-R were those undergoing concomitant meniscectomy with reconstruction.

Intrarater reliability of the functional movement screen.

Abstract Gribble, PA, Brigle, J, Pietrosimone, BG, Pfile, KR, and Webster, KA. Intrarater reliability of the functional movement screen. J Strength Cond Res 27(4): 978–981, 2013—The Functional Movement Screen (FMS) is a tool that quantifies movement patterns as a way to detect performance asymmetries. Although previous study has investigated the reliability of FMS, no current research has examined intrarater reliability or how clinical experience plays a role in the reliability of this tool. In this controlled laboratory study design, repeated measures were used to investigate how experience using the FMS and clinical experience as an athletic trainer (AT) affects the intrarater reliability of FMS testing. Before the data collection, 3 individuals recruited from the university community provided signed informed consent to serve as videotaped models performing the FMS test. The participants (raters) in the study, with different levels of FMS and clinical experience, viewed each of the 3 videotaped models and rated the video models on each exercise of the FMS according to the script that was presented by one of the study investigators. A week later, the participants watched the same videos again, in a different randomized order, and rated each video model on each exercise. After the scores from the participants were collected from both sessions, the intersession scores of the FMS were examined to establish intrarater reliability of all the participants. Additionally, the intrarater reliability of different groups of clinicians and students was compared to make inferences about the influence of clinical experience as an AT along with previous experience using the FMS. The ATs with at least 6 months of experience using the FMS (ATExp group) had the strongest intrarater reliability [intraclass correlation coefficients, ICC (2,1): 0.946], followed by the AT group with moderate reliability [ICC (2,1): 0.771]. This study indicates that intrarater reliability is strong and seems to strengthen when the individuals have experience using the FMS in addition to clinical experience.

Ankle bracing, fatigue, and time to stabilization in collegiate volleyball athletes.

CONTEXT Fatigue has been shown to disrupt dynamic stability in healthy volunteers. It is not known if wearing prophylactic ankle supports can improve dynamic stability in fatigued athletes. OBJECTIVE To determine the type of ankle brace that may be more effective at providing dynamic stability after a jump-landing task during normal and fatigued conditions. DESIGN Two separate repeated-measures analyses of variance with 2 within-subjects factors (condition and time) were performed for each dependent variable. SETTING Research laboratory. PATIENTS OR OTHER PARTICIPANTS Ten healthy female collegiate volleyball athletes participated (age = 19.5 +/- 1.27 years, height = 179.07 +/- 7.6 cm, mass = 69.86 +/- 5.42 kg). INTERVENTION(S) Athletes participated in 3 separate testing sessions, applying a different bracing condition at each session: no brace (NB), Swede-O Universal lace-up ankle brace (AB), and Active Ankle brace (AA). Three trials of a jump-landing task were performed under each condition before and after induced functional fatigue. The jump-landing task consisted of a single-leg landing onto a force plate from a height equivalent to 50% of each participants maximal jump height and from a starting position 70 cm from the center of the force plate. MAIN OUTCOME MEASURE(S) Time to stabilization in the anterior-posterior (APTTS) and medial-lateral (MLTTS) directions. RESULTS For APTTS, a condition-by-time interaction existed (F(2,18) = 5.55, P = .013). For the AA condition, Tukey post hoc testing revealed faster pretest (2.734 +/- 0.331 seconds) APTTS than posttest (3.817 +/- 0.263 seconds). Post hoc testing also revealed that the AB condition provided faster APTTS (2.492 +/- 0.271 seconds) than AA (3.817 +/- 0.263 seconds) and NB (3.341 +/- 0.339 seconds) conditions during posttesting. No statistically significant findings were associated with MLTTS. CONCLUSIONS Fatigue increased APTTS for the AA condition. Because the AB condition was more effective than the other 2 conditions during the posttesting, the AB appears to be the best option for providing dynamic stability in the anterior-posterior direction during a landing task.

Interrater Reliability of the Star Excursion Balance Test

CONTEXT Dynamic postural control has gained popularity as a more useful assessment of function than static postural control. One measurement of dynamic postural control that has increased in frequency of use is the Star Excursion Balance Test (SEBT). Although the intrarater reliability of the SEBT is excellent, few authors have determined interrater reliability. Preliminary evidence has shown poor reliability between assessors. OBJECTIVE To determine interrater reliability using a group of investigators at 2 testing sites. A corollary purpose was to examine the interrater reliability when using normalized and nonnormalized performance scores on the SEBT. DESIGN Descriptive laboratory study. SETTING University research laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 29 healthy participants between 18 and 50 years of age. INTERVENTION(S) Participants were evaluated by 5 raters at 2 testing sites. After participants performed 4 practice trials, each rater assessed 3 test trials in the anterior, posteromedial, and posterolateral reaching directions of the SEBT. MAIN OUTCOME MEASURE(S) Normalized and nonnormalized (leg-length) reaching distances were analyzed. Additionally, the mean and maximum values from the 3 test trials were analyzed, producing a total of 16 variables. RESULTS For all 16 measures, the interrater reliability was excellent. For the normalized maximum excursion distances, the intraclass correlation coefficients (1,1) ranged from 0.86 to 0.92. Reliability for the nonnormalized measurements was stronger, ranging from 0.89 to 0.94. CONCLUSIONS When the raters have been trained by an experienced rater, the SEBT is a test with excellent reliability when used across multiple raters in different settings. This information adds to the body of knowledge that exists regarding the usefulness of the SEBT as an assessment tool in clinical and research practice. Establishing excellent interrater reliability with normalized and nonnormalized scores strengthens the evidence for using the SEBT, especially at multiple sites.

Chronic ankle instability and corticomotor excitability of the fibularis longus muscle

CONTEXT Neuromuscular deficits are common in people with chronic ankle instability (CAI). Corticomotor pathways are very influential in the production of voluntary muscle function, yet these pathways have not been evaluated in people with CAI. OBJECTIVE To determine if corticomotor excitability of the fibularis longus (FL) differs between individuals with unilateral CAI and matched control participants without CAI. DESIGN Case-control study. SETTING Laboratory. Patients or Other Participants: Ten people with CAI (4 men, 6 women; age = 21.2 ± 1.23 years, height = 175.13 ± 9.7 cm, mass = 77.1 ± 13.58 kg) and 10 people without CAI (4 men, ± women; age = 21.2 ± 2.3 years; height = 172.34 ± 8.86 cm, mass = 73.4 ± 7.15 kg) volunteered for this study. MAIN OUTCOME MEASURE(S) Transcranial magnetic stimulation was performed over the motor cortex on neurons corresponding with the FL. All testing was performed with the participant in a seated position with a slightly flexed knee joint and the ankle secured in 10 8 of plantar flexion. The resting motor threshold (RMT), which was expressed as a percentage of 2 T, was considered the lowest amount of magnetic energy that would induce an FL motor evoked potential equal to or greater than 20 l V, as measured with surface electromyography, on 7 consecutive stimuli. In addition, the Functional Ankle Disability Index (FADI) and FADI Sport were used to assess self-reported function. RESULTS Higher RMTs were found in the injured and uninjured FL of the CAI group (60.8% ± 8.4% and 59.1% ± 8.99%, respectively) than the healthy group (52.8% ± 8.56% and 52% ± 7.0%, respectively; F(1,18) = 4.92, P = .04). No leg x group interactions (F(1,18) = 0.1, P = .76) or between-legs differences (F(1,18) = 0.74, P = .40) were found. A moderate negative correlation was found between RMT and FADI (r = 0.4, P = .04) and FADI Sport (r = 0.44, P = .03), suggesting that higher RMT is related to lower self-reported function. CONCLUSIONS Higher bilateral RMTs may indicate deficits in FL corticomotor excitability in people with CAI. In addition, a moderate correlation between RMT and FADI suggests that cortical excitability deficits may be influential in altering function.

Scapular muscle activity in overhead athletes with symptoms of secondary shoulder impingement during closed chain exercises.

OBJECTIVE To determine the amount of muscle activation in 4 scapular muscles in overhead athletes with and without a history of secondary shoulder impingement, during 3 upper extremity closed chain exercises. DESIGN One-between (group), one-within (exercise) repeated measures. SETTING Controlled laboratory study. PARTICIPANTS Overhead athletes (n=15; mean age +/- SD, 21.0+/-2.5 y; mean height +/- SD, 176.0+/-7.8 cm; mean weight +/- SD, 76.1+/-13.4 kg) demonstrating with symptoms of shoulder impingement and overhead athletes (n=15; mean age +/- SD, 20.4+/-3.8 y; mean height +/- SD, 174.1+/-9.7 cm; mean weight +/- SD, 73.3+/-11.7 kg) with no shoulder pathologies. INTERVENTIONS Subjects completed 5 individual trials of a standard push-up, a push-up on an unstable surface, and a revolution on a shoulder rehabilitation device while electromyography (EMG) recorded muscle activity of the serratus anterior, upper trapezius, middle trapezius, and lower trapezius. MAIN OUTCOME MEASURES The mean EMG data for the 4 muscles from the standard push-up, push-up on an unstable surface, and shoulder rehabilitation device trials were normalized as a percentage of a maximum voluntary isometric contraction for each muscle. RESULTS There was a statistically significant interaction for the middle trapezius (F(2,56)=3.856; P=.027). The shoulder impingement push-up on an unstable surface (33.76%+/-26.45%) had significantly greater activation compared with the shoulder impingement standard push-up (25.88%+/-13.76%), the shoulder impingement shoulder rehabilitation device (9.40%+/-5.86%), and the nonpathology push-up on an unstable surface (19.49%+/-7.73%). The shoulder impingement standard push-up had significantly greater activation compared with the shoulder impingement shoulder rehabilitation device and nonpathology standard push-up (17.99%+/-7.31%). The nonpathology standard push-up and nonpathology push-up on an unstable surface had significantly greater activation compared with the nonpathology shoulder rehabilitation device (7.95%+/-4.30%). CONCLUSIONS These results suggest that the muscle activation of the middle trapezius differs in overhead athletes with a history of secondary shoulder impingement compared with those who lack this history during closed chain exercise, as well as within the 3 closed chain exercises. The levels of muscle activation of the serratus anterior and upper trapezius during these closed chain exercises were similar between the 2 groups. These results support the use of closed chain exercises in the rehabilitation process of overhead athletes with secondary shoulder impingement. However, clinicians should consider the muscle(s) of interest when selecting an exercise.