Although sophisticated forceplate systems are available for postural stability analyses, their use is limited in many sports medicine settings because of budgetary constraints. The purpose of this investigation was to compare a clinical method of evaluating postural stability with a force-platform sway measure. Participants completed a battery of three stance variations (double, single, and tandem) on two different surfaces (firm and foam) while standing on a force platform. This arrangement allowed for simultaneous comparisons between forceplate sway measures and clinical assessments using the Balance Error Scoring System (BESS). Significant correlations were revealed for the single-leg and tandem stances on the firm surface and for double, single, and tandem stances on the foam surface. These results suggest that the BESS is a reliable method of assessing postural stability in the absence of computerized balance systems.
Search Results
Relationship between Clinical and Forceplate Measures of Postural Stability
Bryan L. Riemann, Kevin M. Guskiewicz, and Edgar W. Shields
Effect of Rear-Foot Orthotics on Postural Control in Healthy Subjects
Jay Hertel, Craig R. Denegar, W.E. Buckley, Neil A. Sharkey, and Wayne L. Stokes
Objective:
To identify changes in sagittal- and frontal-plane center of pressure (COP) excursion length and velocity during single-leg stance under 6 orthotic conditions.
Design:
1 × 6 repeated-measures.
Setting:
University biomechanics laboratory.
Participants:
Fifteen healthy young adults without excessive forefoot, arch, or rear-foot malalignments.
Measurements:
Selected variables of COP length and velocity were calculated in both the frontal and sagittal planes during three 5-second trials of quiet unilateral stance.
Methods:
Postural control was assessed under 6 conditions: shoe only and 5 orthotics.
Results:
The medially posted orthotic caused the least frontal COP length and velocity, and the Cramer Sprained Ankle Orthotic® caused the greatest frontal-plane sway. No significant differences were found between the different orthotic conditions in sagittal-plane measures.
Conclusions:
Differently posted rear-foot orthotics had various effects on frontal-plane postural control in healthy participants. Further research is needed on pathological populations.
Weight-Bearing and Non-Weight-Bearing Knee-Joint Reposition Sense and Functional Performance
Joshua M. Drouin, Peggy A. Houglum, David H. Perrin, and Bruce M. Gansneder
Objective:
To determine the relationship between weight-bearing (WB) and non-weight-bearing (NWB) joint reposition sense (JRS) and a functional hop test (FH) and to compare performance on these parameters between athletes and nonathletes.
Design:
Repeated-measures ANOVA and Pearson correlations.
Setting:
Research laboratory.
Participants:
40 men (age = 20.8 ± 1.7 y; ht = 176.9 ± 5.8 cm; wt = 82.6 ± 9.5 kg): 20 lacrosse players and 20 nonathletes.
Main Outcome Measures:
Ability to actively reproduce 30° of knee flexion in the WB and NWB conditions and functional performance on a single-leg crossover-hop test.
Results:
No significant correlations were observed between JRS and FH in athletes and nonathletes. No significant differences were observed between athletes and nonathletes in JRS. All participants were significantly more accurate at WB than at NWB JRS.
Conclusions:
There appears to be no relationship between WB or NWB JRS and functional performance, regardless of one’s physical activity level
Rehabilitation for Functional Ankle Instability
Diane Madras and J. Bradley Barr
Objective:
The article presents a focused review of the literature surrounding training methods for addressing the proprioceptive loss and subsequent balance problems that result from inversion ankle sprains.
Data Sources:
The authors searched the MEDLINE and CINAHL databases for the period 1985 through December 2001 using the key words ankle, ankle sprain, and rehabilitation.
Study Selection:
Any study investigating a rehabilitation or prevention program for the proprioceptive or balance aspects of ankle instability was included.
Data Synthesis:
Key components of the training regimen used in each study are described, and major findings are summarized.
Conclusions:
Based on the literature reviewed, there is evidence to suggest that training programs for individuals with ankle instability that include ankle-disk or wobble-board activities help improve single-leg-stance balance and might decrease the likelihood of future sprains.
Assessing Functional Ankle Instability with Joint Position Sense, Time to Stabilization, and Electromyography
Cathleen Brown, Scott Ross, Rick Mynark, and Kevin Guskiewicz
Context:
Functional ankle instability (FAI) is difficult to identify and quantify.
Objective:
To compare joint position sense (JPS), time to stabilization (TTS), and electromy-ography (EMG) of ankle musculature in recreational athletes with and without FAI.
Design:
Case-control compared with t tests and ANOVAs.
Setting:
Sports medicine research laboratory.
Participants:
20 recreational athletes.
Main Outcome Measures:
Passive angle reproduction, TTS, and mean EMG amplitude of the tibialis anterior, peroneals, lateral gastrocnemius, and soleus muscles during single-leg-jump landing.
Results:
No differences in JPS or medial-lateral TTS measures between groups. Significantly longer anterior-posterior TTS (P < .05) in the unstable ankle group. The stable ankle group had significantly higher mean EMG soleus amplitude after landing (P < .05). No other significant differences were found for mean EMG amplitudes before or after landing.
Conclusions:
Subjects with FAI demonstrated deficits in landing stability and soleus muscle activity during landing that may represent chronic adaptive changes following injury.
Improvement of Outcomes With Nonconcurrent Strength and Cardiovascular-Endurance Rehabilitation Conditioning After ACI Surgery to the Knee
Andrea Kay Bailey, Claire Minshull, James Richardson, and Nigel P. Gleeson
Context:
Autologous chondrocyte implantation (ACI) aims to restore hyaline cartilage. Traditionally, ACI rehabilitation is prescribed in a concurrent (CON) format. However, it is well known from studies in asymptomatic populations that CON training produces an interference effect that can attenuate strength gains. Strength is integral to joint function, so adopting a nonconcurrent (N-CON) approach to ACI rehabilitation might improve outcomes.
Objective:
To assess changes in function and neuromuscular performance during 48 wk of CON and N-CON physical rehabilitation after ACI to the knee.
Setting:
Orthopedic Hospital NHS Foundation Trust.
Design:
Randomized control, pilot study.
Participants:
11 patients (9 male, 2 female; age 32.3 ± 6.6 y; body mass 79.3 ±10.4 kg; time from injury to surgery 7.1 ± 4.9 mo [mean ± SD]) randomly allocated to N-CON:CON (2:1).
Interventions:
Standardized CON and N-CON physiotherapy that involved separation of strength and cardiovascular-endurance conditioning.
Main Outcome Measures:
Function in the single-leg-hop test, patient-reported outcomes (Knee injury and Osteoarthritis Outcome Score [KOOS], International Knee Documentation Committee subjective questionnaire [IKDC]), and neuromuscular outcomes of peak force (PF), rate of force development (RFD), electromechanical delay (EMD), and sensorimotor performance (force error [FE]) of the knee extensors and flexors of the injured and noninjured legs, measured presurgery and at 6, 12, 24, and 48 wk postsurgery.
Results:
Factorial ANOVAs with repeated measures of group by leg and by test occasion revealed significantly superior improvements for KOOS, IKDC, PF, EMD, and FE associated with N-CON vs CON rehabilitation (F 1.5, 13.4 GG = 3.7−4.7, P < .05). These results confirm increased peak effectiveness of N-CON rehabilitation (~4.5−13.3% better than CON over 48 wk of rehabilitation). N-CON and CON showed similar patterns of improvement for single-leg-hop test and RFD.
Conclusions:
Nonconcurrent strength and cardiovascular-endurance conditioning during 48 wk of rehabilitation after ACI surgery elicited significantly greater improvements to functional and neuromuscular outcomes than did contemporary concurrent rehabilitation.
Negative Effects on Postural Control After Anterior Cruciate Ligament Reconstruction as Measured by the Balance Error Scoring System
Mason D. Smith and David R. Bell
Context:
Anterior cruciate ligament (ACL) reconstruction is the standard of care for individuals with ACL rupture. Balance deficits have been observed in patients with ACL reconstruction (ACLR) using advanced posturography, which is the current gold standard. It is unclear if postural-control deficits exist when assessed by the Balance Error Scoring System (BESS), which is a clinical assessment of balance.
Objective:
The purpose of this study is to determine if postural-control deficits are present in individuals with ACLR as measured by the BESS.
Participants:
Thirty participants were included in this study. Fifteen had a history of unilateral ACLR and were compared with 15 matched controls.
Interventions:
The BESS consists of 3 stances (double-limb, single-limb, and tandem) on 2 surfaces (firm and foam). Participants begin in each stance with hands on their hips and eyes closed while trying to stand as still as possible for 20 s.
Main Outcome Measures:
Each participant performed 3 trials of each stance (18 total), and errors were assessed during each trial and summed to create a total score.
Results:
We observed a significant group × stance interaction (P = .004) and a significant main effect for stance (P < .001). Post hoc analysis revealed that the ACLR group had worse balance on the single-leg foam stance than did controls. Finally, the reconstructed group had more errors when total BESS score was examined (P = .02).
Conclusions:
Balance deficits exist in individuals with ACLR as measured by the BESS. Total BESS score was different between groups. The only condition that differed between groups was the single-leg stance on the unstable foam surface.
Test-Retest Reliability and Practice Effects of the Stability Evaluation Test
Richelle M. Williams, Matthew A. Corvo, Kenneth C. Lam, Travis A. Williams, Lesley K. Gilmer, and Tamara C. Valovich McLeod
Context: Postural control plays an essential role in concussion evaluation. The Stability Evaluation Test (SET) aims to objectively analyze postural control by measuring sway velocity on the NeuroCom VSR portable force platform (Natus, San Carlos, CA). Objective: To assess the test-retest reliability and practice effects of the SET protocol. Design: Cohort. Setting: Research laboratory. Patients or Other Participants: 50 healthy adults (20 men, 30 women, age 25.30 ± 3.60 y, height 166.60± 12.80 cm, mass 68.80 ± 13.90 kg). Interventions: All participants completed 4 trials of the SET. Each trial consisted of six 20-s balance tests with eyes closed, under the following conditions: double-leg firm (DFi), single-leg firm (SFi), tandem firm (TFi), double-leg foam (DFo), single-leg foam (SFo), and tandem foam (TFo). Each trial was separated by a 5-min seated rest period. Main Outcome Measures: The dependent variable was sway velocity (deg/s), with lower values indicating better balance. Sway velocity was recorded for each of the 6 conditions as well as a composite score for each trial. Test-retest reliability was analyzed across 4 trials with intraclass correlation coefficients (ICCs). Practice effects analyzed with repeated measures analysis of variance, followed by Tukey post hoc comparisons for any significant main effects (P < .05). Results: Sway-velocity reliability values were good to excellent: DFi (ICC = .88; 95%CI: .81, .92), SFi (ICC = .75; 95%CI: .61, .85), TFi (ICC = .84; 95%CI: .75, .90), DFo (ICC = .83; 95%CI: .74, .90), SFo (ICC = .82; 95%CI: .72, .89), TFo (ICC = .81; 95%CI: .69, .88), and composite score (ICC = .93; 95%CI: .88, .95). Significant practice effects (P < .05) were noted on the SFi, DFo, SFo, TFo conditions and composite scores. Conclusions: Our results suggest the SET has good to excellent reliability for the assessment of postural control in healthy adults. Due to the practice effects noted, a familiarization session is recommended (ie, all 6 conditions) before data are recorded. Future studies should evaluate injured patients to determine meaningful change scores during various injuries.
Determining Meaningful Changes in Pelvic-On-Femoral Position during the Trendelenburg Test
James W. Youdas, Sara T. Mraz, Barbara J. Norstad, Jennifer J. Schinke, and John H. Hollman
Context:
Hip abductor muscle weakness is related to many lower extremity injuries. A simple procedure, the Trendelenburg test, may be used to assess hip abductor performance in patient populations.
Objective:
To describe the minimal detectable change (MDC) in pelvic-on-femoral (P-O-F) position of the stance limb during the Trendelenburg test.
Setting:
Laboratory.
Participants:
45 healthy women (28 ± 8 years) and 45 healthy men (33 ± 11 years).
Main Outcome Measures:
P-O-F position in degrees in single-leg stance. Results: Baseline P-O-F position (hip adduction) was 83° ± 3° with a range from 76° to 94°. The intratester reliability (ICC3,1 for measurement of P-O-F position using a universal goniometer was 0.58 with a standard error of measurement (SEM) of 2°. The minimal detectable change (MDC) was calculated to be 4°.
Conclusions:
If a person’s P-O-F position changes less than 4° between measurements, then the P-O-F position is within measurement error and it can be determined that there has been no change in the performance of the hip abductor muscles when examined by the Trendelenburg test.
Examination of a Clinical method of Assessing Postural Control during a Functional Performance Task
Bryan L. Riemann, Nancy A. Caggiano, and Scott M. Lephart
Postural control and functional performance tests are often used separately during orthopedic postinjury assessments. The purpose of this investigation was to examine a clinical method of assessing postural control during a functional performance task. Thirty participants were divided into two groups. The first group was tested three times, the second group only once. The same tester evaluated each participant's performance during all testing sessions, and during the first two testing sessions (Group 1) two additional testers evaluated each performance. Intraclass correlational coefficients between the three testers ranged from .70 to .92. Session 1 (Group 1) scores were pooled with Group 2 scores, and correlational analyses were conducted between participant height and performance; no significant relationships were revealed. The scores from Group 1 were analyzed using between-days repeated-measures ANOVAs. Results revealed significant improvement between Sessions 1 and 3 for the static portion of the test. The results suggest that the multiple single-leg hop-stabilization test offers a method of assessing postural control during a functional performance task.