Postural control after anterior cruciate ligament reconstruction and functional rehabilitation

Is Visual Reliance Increased in Athletes After ACL Injury? A Scoping Review

BACKGROUND

Individuals with anterior cruciate ligament (ACL) injury often exhibit visual cognitive deficits during tasks that require neuromuscular control. In this paper, we present evidence of increased visual reliance after ACL injury during a range of clinically applicable cognitive-motor tasks. This information is essential to strengthen the scientific rationale for therapeutic interventions that target maladaptive neuroplasticity and may translate to improved return-to-sport (RTS) outcomes following ACL injury.

OBJECTIVES

The objectives of this study are (1) to determine if visual reliance is present during common rehabilitation-based assessments after ACL deficiency (ACL-D) or ACL reconstruction (ACL-R), (2) to describe how visual reliance is assessed during such tasks, and (3) to provide information to help clinicians and patients understand the clinical relevance of cognitive load in the assessment and intervention of visual reliance.

DESIGN

Scoping review.

LITERATURE SEARCH

We searched MEDLINE, EMBASE, CINAHL, SCOPUS, and PEDro databases.

STUDY SELECTION CRITERIA

Only primary studies published in English were included without time limitations.

DATA SYNTHESIS

Qualitative analysis of the included studies was performed.

RESULTS

We synthesized the results of 23 studies. A total of 7 studies (31%) included patients with ACL-D, 15 studies (65%) included patients with ACL-R, and 1 study (4%) included patients with ACL-D and ACL-R. Evaluation of tasks, task evaluation setting, visual conditions, outcome measures, and presence of increased visual reliance were identified. Most studies investigating patients with ACL-D, contrary to those with ACL-R, exhibited worse postural stability during eyes-closed conditions than uninjured controls. Complete visual obstruction (i.e., eyes closed or blindfolded) was the most frequently reported method to disrupt vision (52%). The addition of a visual-cognitive challenge resulted in significantly worse postural stability in patients with ACL-R compared with controls.

CONCLUSIONS

Visual reliance was most commonly assessed during single leg stance with complete visual obstruction. The majority of studies on patients with ACL-D indicate that they exhibit poorer postural stability in eyes-closed conditions when compared with uninjured controls, which suggests increased visual reliance. There is less evidence of visual reliance in patients who have undergone ACL-R compared with those with ACL-D. Adding a visual-cognitive load was found to be more effective in inducing postural stability deficits in individuals who have undergone ACL-R.

LEVEL OF EVIDENCE

IV. The protocol was a priori registered on Open Science Framework ( https://osf.io/p4j95/ ).

The effect of stroboscopic visual disruption on static stability measures in anterior cruciate ligament reconstructed individuals

BACKGROUND

Those who undergo ACL reconstruction are at an increased risk of suffering a second ACL injury. A suggested rationale for the increased injury risk is sensory reweighting to the visual system to compensate for a lack of somatosensory information from the knee. Understanding this proposed visual reliance may help clinicians improve return to sport outcomes and reduce the risk of a subsequent ACL injury.

METHODS

Thirteen ACL reconstructed individuals and thirteen matched controls completed two common static postural control assessments under three different visual conditions; eyes open, low visual disruption, and high visual disruption. Center of pressure data was collected for 30 s using force plates. Static postural stability was evaluated using the following: 1) root mean square distance, 2) mean velocity, 3) sway area, and 4) mean frequency.

FINDINGS

No significant interactions between group and vision were observed. Significant differences between groups were observed for mean frequency in the double-limb stance (p < .05). Additionally, significant differences were observed for visual conditions in both double-limb (mean velocity; p < .05) and single-limb stances (root mean square distance, mean velocity, sway area, and mean frequency; p < .05).

INTERPRETATION

The findings of the current study suggest that ACL reconstructed individuals, who are at least two years removed from surgery, do not rely on visual information to a greater extent than controls during static postural stability assessments. Stroboscopic glasses may be a cost-effective alternative for rehabilitation purposes compared to the traditional binary eyes open vs. eyes closed methods.

Dependence on visual information in patients with ACL injury for multi-joint coordination during single-leg squats: a case control study

BACKGROUND

The influence of vision on multi-joint control during dynamic tasks in anterior cruciate ligament (ACL) deficient patients is unknown. Thus, the purpose of this study was to establish a new method for quantifying neuromuscular control by focusing on the variability of multi-joint movement under conditions with different visual information and to determine the cutoff for potential biomarkers of injury risk in ACL deficient individuals.

METHODS

Twenty-three ACL deficient patients and 23 healthy subjects participated in this study. They performed single-leg squats under two different conditions: open eyes (OE) and closed eyes (CE). Multi-joint coordination was calculated with the coupling angle of hip flexion, hip abduction and knee flexion. Non-linear analyses were performed on the coupling angle. Dependence on vision was compared between groups by calculating the CE/OE index for each variable. Cutoff values were calculated using ROC curves with ACL injury as the dependent variable and significant variables as independent variables.

RESULTS

The sample entropy of the coupling angle was increased in all groups under the CE condition (P < 0.001). The CE/OE index of coupling angle variability during the descending phase was higher in ACL deficient limbs than in the limbs of healthy participants (P = 0.036). The CE/OE index of sample entropy was higher in the uninjured limbs of ACL deficient patients than in the limbs of healthy participants (P = 0.027). The cutoff value of the CE/OE index of sample entropy was calculated to be 1.477 (Sensitivity 0.957, specificity 0.478).

CONCLUSION

ACL deficient patients depended on vision to control multiple joint movements not only on the ACL deficient side but also on the uninjured side during single leg squat task. These findings underscore the importance of considering visual dependence in the assessment and rehabilitation of neuromuscular control in ACL deficient individuals.

Protocol for double-blinded randomized trial to enhance postural control after anterior cruciate ligament reconstruction by balance training and concurrent cognitive demands or external focus of attention

Anterior cruciate ligament (ACL) injury is one of the most common injuries among athletes that lead to postural control disorders. The aim of this study is to compare the effects of balance training with and without cognitive task and external focus of attention on postural control in individuals with ACL reconstruction. Sixty participants with ACL reconstruction, between the ages of 18 and 47 will be randomly allocated to three group's including routine balance training, balance training with external focus of attention. Patients will be assessed at the baseline, after receiving eight weeks of intervention, and four weeks later. A double-blinded design will be used. Center of pressure data acquired from a forceplate will be used to assess amount and velocity of sway, local dynamical stability, and global stability of upright balance. Also, dynamic balance will be assessed using Star Excursion balance test. The results of this research will be used to establish effectiveness of treatment strategies for postural control in individuals with anterior cruciate ligament reconstruction. The suggested interventions would be clinically applicable in the athlete with ACL injury.

An obstacle clearance test for evaluating sensorimotor control after anterior cruciate ligament injury: A kinematic analysis

Sensorimotor deficits, particularly proprioceptive, are often reported following rupture of the anterior cruciate ligament (ACL). High secondary injury rates and long-term negative consequences suggest that these deficits are not properly identified using current assessment methods. We explored a novel obstacle clearance test to evaluate sensorimotor control in individuals following ACL reconstruction (ACLR) and rehabilitation. Thirty-seven post-ACLR individuals, 23 nonathletic asymptomatic controls (CTRL), and 18 elite athletes stepped over a hurdle-shaped obstacle, downward vision occluded, aiming for minimal clearance. Kinematic outcomes (3D motion capture) for the leading and trailing legs, for two unpredictably presented obstacle heights, were categorized into Accuracy: vertical foot clearance and minimal distance from the obstacle; Variability: end-point and hip/knee trajectory; and Symmetry: trunk/hip/knee crossing angles, hip-knee-ankle movement, and velocity curves. Accuracy was worse for CTRL compared with both other groups. ACLR had less leading and trailing vertical foot clearance with their injured compared with their noninjured leg. ACLR and athletes had less crossing knee flexion in their injured/nondominant legs compared with their contralateral leg, both leading and trailing. ACLR showed greater trunk flexion when crossing with their injured leg, both leading and trailing. For the leading leg, ACLR showed greater asymmetry for the hip-knee-ankle velocity curve compared with elite athletes. Trailing leg trajectory variability was lower for ACLR compared with CTRL and athletes for higher obstacles. Clinical significance: Sensorimotor deficits in individuals post-ACLR were reflected by greater asymmetry and less variable (more stereotypical) trajectories rather than limb positioning ability. This consideration should be addressed in clinical evaluations.

Quantitative assessment of postural balance in patients with chronic anterior cruciate ligament injury- A controlled study

PURPOSE

Evaluation of single and double limb support postural balance in patients with Anterior cruciate ligament (ACL)injury and comparison of the postural strategy adopted after ACL injury/deficiency(ACLD) with that of an age-matched healthy individual.

METHODS

The study group that included 33 subjects confirming inclusion criteria had undergone postural balance assessment using the HUMAC Balance system. The parameters of the center of pressure excursion were recorded on a force plate and compared with age, BMI matched 66 healthy volunteers of control group. The center of pressure excursions was monitored using dependable variables such as sway path length(cm), the average velocity of sway(cm/sec), and the mean COP stability score(%). The mobility component was recorded as the percentage (%) of time spent on each target.

RESULT

A decrease in postural balance in the injury group was evidenced by a statistically significant decrease of stability score(p = 0.015), increase in path length(p = 0.002) and decrease on time on target mean score (p= <0.001),. Although, the stability score path length and average sway velocity scores in the sound limb of the ACLD group showed impaired balance, the differences were not statistically significant (p = 0.180, p = 0.561, and p = 0.639 respectively) when compared with the dominant limb of the control group.

CONCLUSION

HUMAC balance system is an effective and simplified measure for quantifying postural balance. Although overall postural stability in ACL injury is impaired, static postural balance is maintained by the compensatory of strategy of sound limb. However, the quantitative parameters of postural stability for the sound limb, despite of a lower mean value, did not show statistically significant differences from the dominant limb of the controlled group.

Body Balance after Fascial Therapy in Athletes with Soft Lower Limb Muscle Injuries

Background: Most injuries in competitive sports are due to overstrain and excessive muscular and fascial tension. This study aimed to assess the effects of a single session of fascial therapy on balance and lower limb weight-bearing in professional athletes following a lower limb soft-tissue injury. Methods: A pedobarographic platform was used to assess the weight-bearing on both lower limbs and corporal balance. A total of 41 athletes with an acute soft-tissue injury involving the quadriceps femoris muscle were included in the study. Each patient underwent myofascial therapy in the injured limb only. The therapy was intended to release tension and improve proprioception. Results: The injured and healthy limbs showed significant asymmetry in body weight distribution. Before treatment, the patients bore less weight on the injured limb than on the healthy limb. After fascial therapy, eyes-closed tests showed an improved weight distribution symmetry between the two lower limbs. There were no significant differences in the values of the evaluated balance parameters between those measured at baseline and those measured after the therapy, measured after the rehabilitation session. Conclusions: A single fascial therapy session has a beneficial effect on corporal balance in runners with an injured lower limb.

The effectiveness of vibration therapy for muscle peak torque and postural control in individuals with anterior cruciate ligament reconstruction: a systematic review and meta-analysis of clinical trials

Objective

This study aimed to review and summarize the existing evidence on the effectiveness of vibration therapy (VT) in comparison with conventional rehabilitation in anterior cruciate ligament (ACL)-reconstructed patients considering muscle peak torque and postural control.

Methods

We searched available online databases for relevant studies published up to February 2020. All randomized clinical trials investigating the effect of VT on quadriceps peak torque, hamstring peak torque, and postural control (closed-eye and open-eye) were included. Overall, 13 clinical trials with a total sample size of 407 participants were included for the meta-analysis. We used the pooled mean difference with random effects model for meta-analyses. We assessed the heterogeneity of the studies using the I² and Cochran’s Q test. Meta-regression analysis was used to assess the source of heterogeneity.

Results

We found that VT significantly improved hamstring peak torque [weighted mean difference (WMD) 12.67, 95% CI 4.51–20.83] and quadriceps peak torque (WMD 0.11, 95% CI −0.06 to 0.29). However, subgroup analysis showed a significant increase in mentioned muscles’ peak torque in studies employing interventions including both local muscle vibration (LMV) and vibration frequency higher than 100 Hz (WMD 20.84, 95% CI 11.75–29.93). With regard to postural control, we observed a significant improvement only in open-eye mediolateral postural control (WMD 0.26, 95% CI −1.26 to 1.77).

Conclusion

This study suggests that VT, especially LMV type with vibration frequency higher than 100 Hz, can be effective in rehabilitation of ACL-reconstructed patients. Although improvement in the peak torque of hamstring and quadriceps muscles was seen, there was no significant improvement in postural control, especially closed-eye, in comparison with conventional rehabilitation.

Level of evidence

1.

Highlights

Vibration therapy can increase hamstring peak torque in individuals with ACL reconstruction.

Local muscle vibration type in comparison with whole-body vibration is recommended for ACL-reconstructed patients.

Vibration frequency higher than 100 Hz is preferred in ACL-reconstructed rehabilitation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10195-021-00589-5.

Gaze Accuracy Differences During Single-Leg Balance Following Anterior Cruciate Ligament Reconstruction

CONTEXT

Individuals following anterior cruciate ligament reconstruction (ACLR) demonstrate altered postural stability and functional movement patterns. It is hypothesized that individuals following ACLR may compensate with sensory adaptations with greater reliance on visual mechanisms during activities. It is unknown if visual compensatory strategies are implemented to maintain postural stability during functional tasks.

OBJECTIVE

To examine visual gaze accuracy during a single-leg balance task in individuals following ACLR compared with healthy, active controls.

DESIGN

Case control.

SETTING

Controlled laboratory.

PARTICIPANTS

A total of 20 individuals (10 ACLR and 10 healthy controls) participated in the study.

DATA COLLECTION AND ANALYSIS

Visual gaze patterns were obtained during 20-second single-leg balance trials while participants were instructed to look at presented targets. During the Stationary Target Task, the visual target was presented in a central location for the duration of the trial. The Moving Target Task included a visual target that randomly moved to 1 of 9 target locations for a period of 2 seconds. Targets were stratified into superior, middle, and inferior levels for the Moving Target Task.

RESULTS

The Stationary Target Task demonstrated no differences in visual error between groups (P = .89). The Moving Target Task demonstrated a significant interaction between group and target level (F2,36 = 3.76, P = .033). Individuals following ACLR demonstrated greater visual error for the superior targets (ACLR = .70 [.44] m, healthy = .41 [.21] m, Cohen d = 0.83 [0.06 to 1.60]) and inferior targets (ACLR = .68 [.25] m, healthy = .33 [.16] m, Cohen d = 1.67 [0.81 to 2.52]).

CONCLUSION

Individuals following ACLR demonstrate greater visual error during settings of high or low visual stimuli compared with healthy individuals to maintain single-limb postural stability. This population may rely on visual input to compensate for the somatosensory changes following injury.

Lower extremity prism adaptation in individuals with anterior cruciate ligament reconstruction

BACKGROUND

Emerging research has proposed a growing reliance on visual processing during motor performance in individuals following anterior cruciate ligament reconstruction. Reconstructed individuals display increased activation of visual processing areas during task execution and exhibit dramatic performance decrements when vision is completely removed, however the effect of visual information manipulation on performance remains unknown. The purpose of this study was to determine how manipulation of visual information changes performance in persons with anterior cruciate ligament reconstruction.

METHODS

Twenty-one persons with anterior cruciate ligament reconstruction and 21 matched healthy adults reached to a target with the toe of the involved limb 50 times while wearing prism goggles that vertically shifted their visual field. Toe kinematics were collected to quantify endpoint error and reaching behavior.

FINDINGS

Statistical analyses failed to detect significant differences, evidencing both groups performed similarly with respect to endpoint error, movement duration, peak and maximum endpoint velocities, and initial direction error.

INTERPRETATION

When provided inaccurate information via a visual field perturbation, both groups demonstrated comparable adaptation and post-adaptation behavior. These results suggest this sample of persons with anterior cruciate ligament reconstruction are able to effectively integrate information across sensory systems as well as non-injured individuals.

Postural stability and regulation before and after anterior cruciate ligament reconstruction - A two years longitudinal study

OBJECTIVES

To evaluate postural regulation and stability among patients who underwent anterior cruciate ligament reconstruction (ACLR) and rehabilitation over a two-year follow-up period.

DESIGN

Longitudinal; SETTING: Biomechanics laboratory; PARTICIPANTS: 30 ACLR patients (32.0 ± 12.2 years, 14 males) with isolated ACL rupture.

MAIN OUTCOME MEASURES

Postural regulation was tested before ACLR, as well as at six-weeks, twelve-weeks, six-months, one-year and two-years post-ACLR and standardized rehabilitation. Postural regulation was measured for stability indicator (ST), weight distribution index (WDI), synchronization (foot coordination) and sway intensities (postural subsystems).

RESULTS

Significant time effects (pre-vs. two-years postoperative) were found for WDI (η_p² = 0.466), synchronization (η_p² = 0.368), mediolateral weight distribution (η_p² = 0.349), ST (η_p² = 0.205), visual/nigrostriatal systems (η_p² = 0.179) and peripheral-vestibular system (η_p² = 0.102). The largest difference (preoperative: η_p² = 0.180) to the matched sample was calculated for WDI. The most significant differences to the matched sample were observed for ST (preoperative: η_p² = 0.126; six-weeks postoperative: η_p² = 0.103) and WDI (preoperative: η_p² = 0.180; six-weeks postoperative: η_p² = 0.174).

CONCLUSION

ACLR and rehabilitation influence postural subsystems, postural stability, weight distribution and foot synchronization. Normalization of mediolateral weight distribution requires one year following ACLR. The ACLR leads to a suppression of the somatosensory and cerebellar system which was compensated by a higher activity of the visual and nigrostriatal systems.

Evaluation kinaesthetic proprioceptive deficit after knee anterior cruciate ligament (ACL) reconstruction in athletes

PURPOSE

The objective of this study was to evaluate kinaesthetic proprioceptive deficit after knee anterior cruciate ligament (ACL) reconstruction in two populations of athletes, those in the post-surgery period and those in re-training during the intensive program-training phase.

METHODS

We performed a prospective study in ACL-operated athletes without previous knee injuries, with 32 athletes in each group. Time since surgery in the operated athletes in the post-surgery group was 21 to 35 days, and between three and 9 months in the re-training group. We also analysed a control group of 32 uninjured non-operated subjects with a similar sporting level. Proprioception was evaluated using the threshold to detection of passive motion (TDPM) test with Biodex-type isokinetic equipment comparing operated knees, non-operated knees and control uninjured non-operated group. The control group was tested twice, 1 day apart to control reproducibility, using the intraclass correlation coefficient (ICC). The p-value threshold for statistical significance between different groups in hypothesis testing was <.05.

RESULTS

TDPM reproducibility was excellent (right knee: ICC = 0.80, left knee: ICC =0.72). We found a bilateral kinaesthetic deficit in post-surgery patients compared to the control group (p < 0.001 and p = 0.011), which was significantly higher on the operated side (p = 0.001). Re-training patients had no significant difference between operated and uninjured knees, but had a kinaesthetic deficit on operated limbs (p = 0.036) compared to the control group.

CONCLUSION

There was a bilateral deficit in post-surgery athletes with a significant difference between injured and healthy knees, which could be explained by a change in the central nervous system. Compared to the control group, a proprioceptive deficit was only seen for re-training patients on the operated side and not in the healthy limb. Kinaesthetic recovery may be faster for the uninjured side as initial deficit is lower. Level of evidence II.

Evaluating equilibrium in anterior cruciate ligament reconstruction

[Purpose] The purpose of this review was to summarize available methods and equipment which are administered to evaluate the balance in anterior cruciate ligament reconstruction. [Subjects and Methods] A literature search was performed and reviewed using the narrative approach. This study reviewed English articles concerning balance assessment methods in anterior cruciate ligament reconstruction subjects from 1985 to 2015 using the following key words: Anterior Cruciate Ligament Injury, Anterior Cruciate Ligament Reconstruction, Postural Control, Equilibrium, Balance and Stability. [Results] This review included 44 studies out of 117 initially retrieved articles. These articles were discussed in balance measurement procedure without comparing the effect of various surgical, medical or rehabilitation approaches. [Conclusion] Biodex and EquiTest, functional dynamic tests are of choice in the evaluation and tracking of anterior cruciate ligament reconstruction subjects. Force plate parameters provide information regarding strategies of static postural control and is not sensitive enough to challenge postural control system in physical activities.

Altered lower extremity joint mechanics occur during the star excursion balance test and single leg hop after ACL-reconstruction in a collegiate athlete

The effects of ACL-reconstruction on lower extremity joint mechanics during performance of the Star Excursion Balance Test (SEBT) and Single Leg Hop (SLH) are limited. The purpose of this study was to determine if altered lower extremity mechanics occur during the SEBT and SLH after ACL-reconstruction. One female Division I collegiate athlete performed the SEBT and SLH tasks, bilaterally, both before ACL injury and 27 months after ACL-reconstruction. Maximal reach, hop distances, lower extremity joint kinematics and moments were compared between both time points. Musculoskeletal simulations were used to assess muscle force production during the SEBT and SLH at both time points. Compared to the pre-injury time point, SEBT reach distances were similar in both limbs after ACL-reconstruction except for the max anterior reach distance in the ipsilateral limb. The athlete demonstrated similar hop distances, bilaterally, after ACL-reconstruction compared to the pre-injury time point. Despite normal functional performance during the SEBT and SLH, the athlete exhibited altered lower extremity joint mechanics during both of these tasks. These results suggest that measuring the maximal reach and hop distances for these tasks, in combination with an analysis of the lower extremity joint mechanics that occur after ACL-reconstruction, may help clinicians and researchers to better understand the effects of ACL-reconstruction on the neuromuscular system during the SEBT and SLH.

Effect of cognitive challenge on the postural control of patients with ACL reconstruction under visual and surface perturbations

Our study aimed to evaluate the effect of cognitive challenge on double-leg postural control under visual and surface perturbations of patients with anterior cruciate ligament reconstruction (ACLR) cleared to return to sport. Double-leg stance postural control of 19 rehabilitated patients with ACLR (age: 24.8 ± 6.7 years, time since surgery: 9.2 ± 1.6 months) and 21 controls (age: 24.9 ± 3.7 years) was evaluated in eight randomized situations combining two cognitive (with and without silent backward counting in steps of seven), two visual (eyes open, eyes closed) and two surface (stable support, foam support) conditions. Sway area and sway path of the centre of foot pressure were measured during three 20-s recordings for each situation. Higher values indicated poorer postural control. Generally, postural control of patients with ACLR and controls was similar for sway area and sway path (p > 0.05). The lack of visual anchorage and the disturbance of the plantar input by the foam support increased sway area and sway path (p < 0.001) similarly in both groups. The addition of the cognitive task decreased sway area and sway path (p < 0.001) similarly in both groups. Patients with ACLR who recently completed their rehabilitation have normalized postural control during double-leg stance tests. The use of a dual task paradigm under increased task complexity modified postural control, but in a similar way in patients with ACLR than in healthy controls. Double-leg stance tests, even under challenging conditions, are not sensitive enough to reveal postural control differences between rehabilitated patients with ACLR and controls.

Comparison of an Innovative Rehabilitation, Combining Reduced Conventional Rehabilitation with Balneotherapy, and a Conventional Rehabilitation after Anterior Cruciate Ligament Reconstruction in Athletes

Background

Instability of the knee, related to anterior cruciate ligament injury, is treated by surgical reconstruction. During recovery, a loss of proprioceptive input can have a significant impact. Few studies have evaluated the benefits of rehabilitation of the knee in aquatic environment on functional outcomes.

Objective

This study aimed to compare an innovative rehabilitation protocol combining reduced conventional rehabilitation with aquatic rehabilitation, with a conventional rehabilitation, according to the National French Health Authority, in terms of kinetics, development of proprioceptive skills, and functional improvement of the knee.

Methods

67 patients, who were amateur or professional athletes, were randomized into two groups: 35 patients followed the conventional rehabilitation protocol (Gr1) and 32 patients followed the innovative rehabilitation protocol (Gr2). Patients were evaluated before surgery, and at 2 weeks, 1, 2, and 6 months after surgery using posturography, and evaluation of muscular strength, walking performance and proprioception. This study is multicenter, prospective, randomized, and controlled with a group of patients following conventional rehabilitation (level of evidence I).

Results

For the same quality of postural control, Gr2 relied more on somesthesia than Gr1 at 6 months. The affected side had an impact on postural control and in particular on the preoperative lateralization, at 2 weeks and at 1 month. Lateralization depended on the affected knee, with less important lateralization in Gr2 preoperatively and at 1 month. The quadriceps muscular strength was higher in Gr2 than in Gr1 at 2 and 6 months and muscle strength of the external hamstring was greater in Gr2 than in Gr1 at 6 months. The isokinetic test showed a greater quadriceps muscular strength in Gr2. Gr2 showed a greater walking distance than Gr1 at one month. Gr2 showed an improvement in the proprioceptive capacities of the operated limb in flexion for the first 2 months.

Conclusion

The effectiveness of the innovative rehabilitation program permits faster recovery, allowing for an earlier return to social, sporting, and professional activities. Faster retrieval of knee function following aquatic rehabilitation would prevent both short-term risk of lesions of the contralateral limb due to overcompensation and long-term risk of surgery due to osteoarthritis.

Registration of clinical trials

NCT02225613.

Test-retest reliability of a balance testing protocol with external perturbations in young healthy adults

External perturbations are utilized to challenge balance and mimic realistic balance threats in patient populations. The reliability of such protocols has not been established. The purpose was to examine test-retest reliability of balance testing with external perturbations. Healthy adults (n=34; mean age 23 years) underwent balance testing over two visits. Participants completed ten balance conditions in which the following parameters were combined: perturbation or non-perturbation, single or double leg, and eyes open or closed. Three trials were collected for each condition. Data were collected on a force plate and external perturbations were applied by translating the plate. Force plate center of pressure (CoP) data were summarized using 13 different CoP measures. Test-retest reliability was examined using intraclass correlation coefficients (ICC) and Bland-Altman plots. CoP measures of total speed and excursion in both anterior-posterior and medial-lateral directions generally had acceptable ICC values for perturbation conditions (ICC=0.46 to 0.87); however, many other CoP measures (e.g. range, area of ellipse) had unacceptable test-retest reliability (ICC<0.70). Improved CoP measures were present on the second visit indicating a potential learning effect. Non-perturbation conditions generally produced more reliable CoP measures than perturbation conditions during double leg standing, but not single leg standing. Therefore, changes to balance testing protocols that include external perturbations should be made to improve test-retest reliability and diminish learning including more extensive participant training and increasing the number of trials. CoP measures that consider all data points (e.g. total speed) are more reliable than those that only consider a few data points.

Visual Utilization During Postural Control in Anterior Cruciate Ligament- Deficient and -Reconstructed Patients: Systematic Reviews and Meta-Analyses

OBJECTIVE

To determine whether anterior cruciate ligament-deficient (ACL-D) individuals and individuals with a reconstructed anterior cruciate ligament (ACL-R) rely more heavily on visual information to maintain postural control.

DATA SOURCES

PubMed, CINAHL, and SPORTDiscus databases were searched from their earliest available date to May 24, 2016, using a combination of keywords.

STUDY SELECTION

Articles were included if they reported any instrumented static single-leg balance outcome in both a patient and control sample. The means and SDs of these outcomes must have been reported with both eyes open and eyes closed.

DATA EXTRACTION

Sample sizes, means, and SDs of single-leg balance measures for each group's eyes open and eyes closed testing conditions were extracted. The methodological quality of included studies was independently evaluated by multiple authors using an adapted version of the Quality Index.

DATA SYNTHESIS

Effect sizes were calculated by dividing the differences in change between eyes closed and eyes open in the ACL-D and control group and the ACL-R and control group by the pooled SD from the eyes closed trials for each analysis. Significant differences between the ACL-D and control group (effect size, -1.66; 95% confidence interval [CI], -2.90 to -.41) were noted. The ACL-R and control group were not different (effect size, -.61; 95% CI, -2.17 to .95).

CONCLUSIONS

ACL-D individuals but not individuals with ACL-R demonstrate a greater reliance on visual information during single-leg stance compared with healthy individuals.

Standing balance and inter-limb balance asymmetry at one year post primary anterior cruciate ligament reconstruction: Sex differences in a cohort study of 414 patients

BACKGROUND

Static standing balance can be safely assessed early following anterior cruciate ligament reconstruction (ACLR), and deficits may have important implications for long-term outcomes. This study includes a large cohort of people post-ACLR and has the primary aim of establishing whether inter-limb and sex differences exist, with a secondary aim of assessing the association between static balance variables and other outcome measures.

METHODS

A total of 414 patients with a primary ACLR performed a 30-s static single leg balance test. Centre of pressure (COP) path length, antero-posterior (AP) and medio-lateral (ML) sway range and slow and fast speed COP path-length were examined. Additional measures included single and triple hop distance and symmetry, knee flexion range of motion, ligament laxity and the International Knee Documentation Committee (IKDC) subjective knee evaluation form.

RESULTS

No significant inter-limb balance differences were present in females. Significant, yet small to negligible effect size (ES) differences were present in males for ML range (ES=0.19), and AP and ML axis slow speed path length (ES=0.11 and 0.23 respectively). Significant, negligible to moderate effect size (ES range=<0.01 to 0.60) sex differences were observed, with females showing reduced sway compared to males. No balance variables had associations with any other variable that were greater than weak.

DISCUSSION

Our findings provide evidence that primary ACLR does not appear to negatively impact single leg standing balance on the operated limb more than the non-operated side. The lack of association with other outcome measures warrants further longitudinal examination into the utility of static standing balance assessment.

Normative Data for the NeuroCom Sensory Organization Test in US Military Special Operations Forces

CONTEXT

Postural stability is the ability to control the center of mass in relation to a person's base of support and can be affected by both musculoskeletal injury and traumatic brain injury. The NeuroCom Sensory Organization Test (SOT) can be used to objectively quantify impairments to postural stability. The ability of postural stability to predict injury and be used as an acute injury-evaluation tool makes it essential to the screening and rehabilitation process. To our knowledge, no published normative data for the SOT from a healthy, highly active population are available for use as a reference for clinical decision making.

OBJECTIVE

To present a normative database of SOT scores from a US Military Special Operations population that can be used for future comparison.

DESIGN

Cross-sectional study.

SETTING

Human performance research laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 542 active military operators from Naval Special Warfare Combatant-Craft Crewmen (n = 149), Naval Special Warfare Command, Sea, Air, and Land (n = 101), US Army Special Operations Command (n = 171), and Air Force Special Operations Command (n = 121).

MAIN OUTCOME MEASURE(S)

Participants performed each of the 6 SOT conditions 3 times. Scores for each condition, total equilibrium composite score, and ratio scores for the somatosensory, visual, and vestibular systems were recorded.

RESULTS

Differences were present across all groups for SOT conditions 1 (P < .001), 2 (P = .001), 4 (P > .001), 5 (P > .001), and 6 (P = .001) and total equilibrium composite (P = .000), visual (P > .001), vestibular (P = .002), and preference (P > .001) NeuroCom scores.

CONCLUSIONS

Statistical differences were evident in the distribution of postural stability across US Special Operations Forces personnel. This normative database for postural stability, as assessed by the NeuroCom SOT, can provide context when clinicians assess a Special Operations Forces population or any other groups that maintain a high level of conditioning and training.

Assessment of a Practice Effect in Serial Sensory Organization Testing Scores of Healthy Adults

This study assessed whether a practice effect occurs across five serial administrations of the sensory organization test. Composite equilibrium scores and mean equilibrium scores from 30 healthy volunteers ( M age = 36.9, SD= 12.2 yr.) performing each of the six test conditions were examined using a two-way repeated-measures analysis of variance. Analysis yielded a significant interaction between testing condition and time, as well as significant main effects for both condition and time. Pairwise comparisons showed significant differences among test conditions and the first and second times of test administration. Analysis of simple effects between the two administrations identified significant increases in composite equilibrium scores and mean equilibrium scores on two sway-referenced support surface conditions, vision removed and sway-referenced visual surround. An immediate increase in equilibrium scores suggests clinicians and researchers allow one pracatice trial before recording test scores for baseline measurements.

Postural stability and responses to vibrations in patients after anterior cruciate ligament surgical reconstruction

The aim of the study was to evaluate the effect of surgical reconstruction of anterior cruciate ligament (ACL) on postural stability and responses to lower limb (LL) muscles vibrations. Centre of pressure (CoP) was measured in 17 subjects during stance on firm/foam surface with eyes open/closed and during unilateral vibrations of LL muscles (m. triceps surae - TS, m. quadriceps femoris - Q, m. quadriceps femoris and hamstrings simultaneously - QH). The measurements were performed: 1) preoperatively, 2) six weeks and 3) three months after the reconstruction. Decreased postural stability was documented six weeks after the reconstruction compared to preoperative measurement. Three months after the reconstruction significant improvement was observed during stance on foam surface with eyes closed. Preoperatively, altered reactions of LL with ACL lesion compared to intact LL were manifested by slower response in first 3 s of TS vibration and by increased CoP shift in last 5 s of QH vibration. After the reconstruction, we observed slower CoP reaction and decreased CoP shift during TS vibration of LL with ACL lesion compared to preoperative level. Posturography during quiet stance and during TS vibration reliably detect postural changes due to ACL reconstruction and can be potentially useful in clinical practice.

Dynamic Single-Leg Postural Control Is Impaired Bilaterally Following Anterior Cruciate Ligament Reconstruction: Implications for Reinjury Risk

Study Design Cross-sectional, controlled laboratory study. Background Postural control following anterior cruciate ligament reconstruction (ACLR) primarily has been investigated during static single-leg balance tasks. Little is known about dynamic postural control deficits post-ACLR. Objectives To compare dynamic postural control (bilaterally) in individuals who have undergone ACLR and in healthy controls, and to evaluate the relationship between dynamic postural control and self-reported and objective function. Methods Ninety-seven participants (66 male; median age, 28 years) 12 months post-ACLR and 48 healthy controls (20 male; median age, 30 years) underwent balance assessment using a Nintendo Wii Balance Board during a single-leg squat. Center-of-pressure (CoP) path velocity, as well as CoP amplitude and standard deviation, in both mediolateral (ML) and anteroposterior (AP) directions were recorded. Self-reported function was assessed with the International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC), while hop for distance was used to evaluate functional status. Results Compared to healthy controls, the ACLR group had greater mean CoP path velocity (16% higher, P = .004), ML range (23%, P<.001), ML SD (28%, P<.001), AP range (14%, P = .009), and AP SD (15%, P = .013), indicating worse dynamic balance post-ACLR. Dynamic balance performance was similar between the ACLR limb and the uninjured contralateral limb. The AP SD was weakly associated with hop performance (β = -.2, P = .046); no balance measures were associated with IKDC score. Conclusion Individuals who have undergone ACLR demonstrate impaired dynamic balance bilaterally when performing a single-leg squat, which may have implications for physical function and future injury risk. Routine dynamic balance assessment may help identify patients who could benefit from targeted neuromuscular training programs to improve objective function and potentially lower reinjury risk. J Orthop Sports Phys Ther 2016;46(5):357-364. Epub 21 Mar 2016. doi:10.2519/jospt.2016.6305.

Altered postural control strategies in quiet standing more than 20 years after rupture of the anterior cruciate ligament

AIM

To explore long-term consequences of anterior cruciate ligament (ACL) rupture on postural sway and control strategies during bilateral quiet standing, in subjects treated with or without reconstructive surgery compared to uninjured controls.

METHOD

70 individuals who had unilateral ACL rupture 23±2.4 years ago (33 received ACL reconstructive surgery, ACLR, and 37 had physiotherapy only, ACLPT) and 33 uninjured matched controls (CTRL) (mean age 46±5.3) stood quietly with eyes closed for 3min on a firm and on a compliant surface, respectively. Center of pressure (CoP) was registered with a force plate and postural sway was calculated from center of mass (CoM) derived from 3D kinematics. Sway density (SD) analyses of CoP assessed distance and duration of stable phases. The torque controlling postural sway was estimated from CoP-CoM.

RESULTS

Comparisons across conditions to CTRL revealed larger CoP-CoM-area in ACLR (p=0.017, CI: 10.95, 143.10), but not in ACLPT. Mean distance between SD-peaks was greater for ACLR (p<0.001, CI: 1.73, 5.31) than for ACLPT (p=0.006, CI: 0.56, 4.12) relative to CTRL. Duration of SD-peaks was smaller for both ACLR and ACLPT (p<0.001, CI: -4.04, -1.23 and -3.82, -1.03, respectively) compared to CTRL. CoM-area in the ACL-groups did not differ from CTRL.

CONCLUSIONS

ACL-injured subjects demonstrated greater postural control efforts than CTRL but without significant differences in postural sway. Control efforts were thus not directly associated with sway and further research should be focused on variance in postural control strategies.

Preoperative and postoperative serial assessments of postural balance and fall risk in patients with arthroscopic anterior cruciate ligament reconstruction

BACKGROUND

Impaired postural balance due to somatosensory data loss with mechanical instability has been shown in patients with ACL deficiency.

OBJECTIVE

To assess postural balance in patients with ACL insufficiency prior to surgery and following reconstruction with serial evaluations.

METHODS

Thirty patients (mean age of 27.7 ± 6.7 years) who underwent arthroscopic reconstruction of ACL with bone-patellar tendon-bone autograft were examined for clinical and functional variables at preoperative day and postoperative 12th week. Posturographic analysis were performed by using Tetrax Interactive Balance System (Sunlight Medical Ltd, Israel) at preoperative day, at 4th, 8th, and 12th weeks following reconstruction. Data computed by posturographic software by the considerations of the oscillation velocities of body sways is fall risk as a numeric value (0-100, lower values indicate better condition).

RESULTS

All of the patients (mean age of 27.7 ± 6.7 years) had significant improvements for clinical, functional evaluations and fall risk (p< 0.05). Mean fall risk was within high-risk category (59.9 ± 22.8) preoperatively. The highest fall risk was detected at postoperative 4th week. Patients had high fall risk at 8th week similar to preoperative value. Mean fall risk decreased to low level risk at 12th week. Preoperative symptom duration had relationships with preoperative fall risk and postoperative improvement of fall risk (p= 0.001, r= -0.632, p= 0.001, r= -0.870, respectively). The improvement of fall risk was higher in patients with symptoms shorter than 6 months (p= 0.001).

CONCLUSIONS

According to these results, mean fall risk of patients with ACL insufficiency was within high risk category preoperatively, and fall risk improves after surgical reconstruction, but as the duration of complaints lengthens especially longer than 6 months, the improvement of fall risk decreases following reconstruction.

Body balance control deficiencies following ACL reconstruction combined with medial meniscus suture. A preliminary report

INTRODUCTION

Proprioception makes a critical contribution to body balance. The objective of this study was to evaluate static postural control after anterior cruciate ligament (ACL) reconstruction combined with medial meniscus (MM) suture, comparatively to healthy controls.

HYPOTHESIS

Body balance is adversely affected 2 months after ACL reconstruction combined with MM suture.

PATIENTS AND METHODS

Fifteen patients (12 males and 3 females) aged 20 to 35 years (mean, 26.4 ± 6.0 years) who underwent ACL reconstruction with MM suture were compared to 20 healthy, physically active controls (16 females and 4 males) aged 19 to 23 years (mean, 21.1 ± 1.8 years), most of whom were physiotherapy students. Mean age was not significantly different between the patients and controls. A balance platform was used to estimate static postural control parameters. Each participant performed four tests, two in normal bipedal stance and two in tandem stance; in each stance, one test was done with the eyes open and the other with the eyes closed. We analysed global scores on a standardised 100-point scale and mean centre of pressure (COP) displacement velocity in the sagittal and frontal planes.

RESULTS

Body balance was impaired 2 months after ACL reconstruction with MM suture. Thus, the patients had lower global scores and higher mean COP velocities in both the coronal and sagittal planes.

CONCLUSIONS

Proprioception is impaired after ACL reconstruction with MM suture. Lack of visual control significantly decreases the ability to maintain balance. A balance platform is a useful diagnostic tool for patients with ACL reconstruction and MM suture.

LEVEL OF EVIDENCE

Level II.

Contralateral limb deficit seven months after ACL-reconstruction: an analysis of single-leg hop tests

BACKGROUND

Following ACL-reconstruction, the non-injured leg (NIL) is used as a reference to assess injured leg (IL) recovery. However, deficits have been reported in the NIL questioning its use as a reference. The aim of this study is to assess whether NIL deficits are present while jumping after ACL-reconstruction.

METHODS

Thirteen males who had undergone ACL-reconstruction and 16 healthy subjects took part in the experiment. Jumping performance was assessed during a single and a triple hop for distance. Jumping performance, kinematic and kinetic data were recorded during single leg squat jumps. Values for both the NIL and the IL were compared to those of a control group (CG).

RESULTS

Jumping performance for single and triple hop for distance and single leg squat jump was lower in the NIL than in the CG (p=0.004, p=0.002, and p=0.016, respectively). During the squat jump, the knee joint was more extended and the ankle plantar-flexion was greater at take-off while the peak total moment was 15% lower in the NIL than in the CG (p=0.002, p=0.002, and p=0.009, respectively). We found consistent evolutions in the NIL and the IL compared to the CG for jumping performance, initial joint angles, and peak total moment during the squat jump, but the opposite was found for the ankle and knee joint angles at squat jump take-off.

CONCLUSIONS

Jumping strategies are impaired in the NIL after ACL-R during jump tasks with some deficits matching those observed in the IL and some specific to the NIL.

LEVEL OF EVIDENCE

III, Case control study.

Postural stability deficits during the transition from double-leg stance to single-leg stance in anterior cruciate ligament reconstructed subjects

The goal of this study was to evaluate postural stability during the transition from double-leg stance (DLS) to single-leg stance (SLS) in anterior cruciate ligament reconstructed (ACLR) (n=20) and non-injured control subjects (n=20). All ACLR subjects had fully returned to their pre-injury sport participation. Both groups were similar for age, gender, height, weight, body mass index and activity level. Spatiotemporal center of pressure outcomes of both legs of each subject were measured during the transition from DLS to SLS in eyes open and eyes closed conditions. Movement speed was standardized. The center of pressure displacement after a new stability point was reached during the SLS phase was significantly increased in the ACLR group compared to the control group in the eyes closed condition (P=.001). No significant different postural stability outcomes were found between the operated and non-operated legs. In conclusion, the ACLR group showed postural stability deficits, indicating that these persons may have a decreased ability to stabilize their body after the internal postural perturbation created by the transition from DLS to SLS. The non-operated leg may not be the best reference when evaluating postural stability of the operated leg after ACLR, as no differences were found between legs.

Reliability of Single-leg and Double-leg Balance Tests in Subjects with Anterior Cruciate Ligament Reconstruction and Controls

The purpose of this study was to assess the test-retest reliability of postural balance in patients with anterior cruciate ligament reconstruction (ACL) and controls. Ten healthy subjects and 15 individuals with ACL reconstruction performed single-leg and double-leg balance tests. The center of pressure (COP) was recorded using a pressure platform. For the total COP path, the intraclass correlation coefficient (ICC) ranged from 0.79 to 0.91. For the COP standard deviation, the ICCs ranged from 0.68 to 0.94. For the COP velocity, the ICCs ranged from 0.72 to 0.91. The sway area and ellipse scores displayed ICCs values of 0.67 to 0.95 and 0.53 to 0.92, respectively. The ICCs were higher for double leg tests compared with single-stance ones. These results indicate that 30 s balance tests in double and single-leg stance are reliable tools to assess static balance. The use of such tests to monitor rehabilitation programs following ACL reconstruction is recommended.

Force-controlled biting alters postural control in bipedal and unipedal stance

Human posture is characterised by inherent body sway which forces the sensory and motor systems to counter the destabilising oscillations. Although the potential of biting to increase postural stability has recently been reported, the mechanisms by which the craniomandibular system (CMS) and the motor systems for human postural control are functionally coupled are not yet fully understood. The purpose of our study was, therefore, to investigate the effect of submaximum biting on postural stability and on the kinematics of the trunk and head. Twelve healthy young adults performed force-controlled biting (FB) and non-biting (NB) during bipedal narrow stance and single-leg stance. Postural stability was quantified on the basis of centre of pressure (COP) displacements, detected by use of a force platform. Trunk and head kinematics were investigated by biomechanical motion analysis, and bite forces were measured using a hydrostatic system. The results revealed that FB significantly improved postural control in terms of reduced COP displacements, providing additional evidence for the functional coupling of the CMS and human posture. Our study also showed, for the first time, that reductions in the sway of the COP were accompanied by reduced trunk and head oscillations, which might be attributable to enhanced trunk stiffness during FB. This physiological response to isometric activation of the masticatory muscles raises questions about the potential of oral motor activity as a strategy to reduce the risk of falls among the elderly or among patients with compromised postural control.

[Influence of anterior cruciate reconstruction on postural stability: A pre- and postoperative comparison]

BACKGROUND

Ruptures of the anterior cruciate ligament (ACL) lead to an anteromedial rotational instability in the knee joint and, thus, to a deterioration of the patient's ability to stand (postural control). It still remains unclear whether postural control can be restored by ACL reconstruction. The aim of this study was to investigate the effect of a unilateral ACL graft on the ability to stably stand on the injured leg using computer-aided dynamic posturography (CDP); the stability indices on standing on one leg were compared pre- and postoperatively.

PATIENTS AND METHODS

A total of 25 patients were studied after unilateral ACL injury and subsequent ACL reconstruction using CDP. The average time of follow-up was 608 days (range 357-821 days). The ability to stably stand on the healthy and injured leg was compared and evaluated for significant differences.

RESULTS

There was a significant improvement of postural control after ACL reconstruction. The Overall Stability Index (OSI) for the leg with ACL rupture was 3.7° ± 1.6° preoperatively and 3.0° ± 1.1° postoperatively (p < 0.05). In the postoperative comparison with the healthy leg, the value in the operated leg was 3.0° ± 1.1° and the healthy leg was 3.0° ± 1.4° (p = 0.99).

CONCLUSIONS

ACL replacement can be improve stability compared to the preoperative value by about 21% and even the stability level of the contralateral healthy knee can be achieved.

Assessment of standing balance deficits in people who have undergone anterior cruciate ligament reconstruction using traditional and modern analysis methods

Modern methods of assessing standing balance such as wavelet and entropy analysis could provide insight into postural control mechanisms in clinical populations. The aim of this study was to examine what effect anterior cruciate ligament reconstruction (ACLR) has on traditional and modern measures of balance. Ninety subjects, 45 who had undergone ACLR and 45 matched controls, performed single leg static standing balance tests on their surgical or matched limb on a Nintendo Wii Balance Board. Data were analysed in the anterior-posterior axis of movement, which is known to be affected by ACLR. The traditional measures of path velocity, amplitude and standard deviation were calculated in this plane. Additionally, sample entropy and discrete wavelet transform derived assessment of path velocity in four distinct frequency bands related to (1) spinal reflexive loops and muscle activity, (2) cerebellar, (3) vestibular, and (4) visual mechanisms of postural control were derived. The ACLR group had significantly increased values in all traditional measures and all four frequency bands. No significant difference was observed for sample entropy. This indicated that whilst postural sway was amplified in the ACLR group, the overall mechanism used by the patient group to maintain balance was similar to that of the control group. In conclusion, modern methods of signal analysis may provide additional insight into standing balance mechanisms in clinical populations. Future research is required to determine if these results provide important and unique information which is of benefit to clinicians.

Attentional demands of postural control during single leg stance in patients with anterior cruciate ligament reconstruction

The aim of this study was to investigate the amount of attention demands of postural control in patients with anterior cruciate ligament-reconstruction (ACL-R), by comparing the pattern of posture-cognition interaction between two groups of ACL-R patients (n=25) and healthy matched controls (n=25). All participants were examined during single-leg stance on a balance board under both single- and dual-task conditions in 4 dynamic balance tests. These tests were standing on the injured and uninjured legs with straight or flexed knees. The corresponding dominant and non-dominant legs of healthy group were considered as controls. Contact frequency and contact time were acquired as a measure of postural performance. Cognitive performance was assessed by counting the number of errors in a silent backward digit span task. The results of analysis of variance showed a significant higher contact frequency and longer contact time in patients with ACL-R compared to healthy matched controls (p<0.02). Moreover, the ACL-R patients showed a significantly higher contact frequency and longer contact time during dual-task compared to single-task conditions (p<0.01). This pattern of posture-cognition interference was not observed in the healthy control group. In conclusion, patients who had undergone ACL-R surgery demonstrated poorer balance stability during single-leg stance than healthy controls. Also, simultaneous execution of the cognitive task during standing caused a significant deterioration in postural stability which indicates decreased automaticity (increased attention demanding) of postural control in patients with ACL-R compared to healthy controls.

The effect of early whole-body vibration therapy on neuromuscular control after anterior cruciate ligament reconstruction: a randomized controlled trial

BACKGROUND

Despite rehabilitation training, deficiency in knee joint position sense, muscular performance, postural control, and functional ability is common after anterior cruciate ligament reconstruction (ACLR). Whole-body vibration therapy (WBVT), which is initiated from 3 months postoperatively, has proven benefits. However, the effect of earlier WBVT is unknown.

PURPOSE

To investigate the effect of early WBVT on neuromuscular control after ACLR.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 48 patients with unilateral complete isolated ACL tears were recruited. Single-bundle hamstring ACLR was performed in all patients. After surgery, they were randomly assigned to either the reference or treatment group. Reference group patients received conventional ACL rehabilitation, while treatment group patients received 8 weeks of WBVT in addition to conventional rehabilitation, starting from 1 month postoperatively. Joint position sense, postural control, and knee isokinetic performance were assessed before surgery and at 1, 3, and 6 months postoperatively using the Biodex dynamometer, Biodex Stability System, and Cybex NORM, respectively. Knee range of motion (ROM), stability (manual testing and KT-1000 arthrometer), and functional ability (single-legged hop test, triple hop test, shuttle run test, and carioca test) were also examined. Two-way repeated-measures analysis of variance and the Mann-Whitney U test were used for statistical analysis.

RESULTS

There was no complication throughout the rehabilitation. All patients achieved full knee ROM and stable knee joints at 6 months after surgery. The WBVT group demonstrated significantly better postural control, muscle performance, single-legged hop, and shuttle run (P < .05) than the reference group, but there was no significant difference in knee joint position sense, triple hop, carioca, ROM, and stability (P > .05).

CONCLUSION

Early WBVT started from 1 month postoperatively was an effective training method without compromising knee ROM and stability. It improved postural control, isokinetic performance, single-legged hop, and shuttle run but not knee joint position sense, triple hop, and carioca.

Exergaming and static postural control in individuals with a history of lower limb injury

CONTEXT

Therapeutic exercise programs that incorporate real-time feedback have been reported to enhance outcomes in patients with lower extremity joint injuries. The Wii Fit has been purported to improve balance, strength, flexibility, and fitness.

OBJECTIVE

To determine the effects of Wii Fit rehabilitation on postural control and self-reported function in patients with a history of lower limb injury.

DESIGN

Single-blinded, randomized controlled trial.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twenty-eight physically active participants with a history of lower limb injuries were randomly assigned to 1 of 3 groups (9 Wii Fit, 10 traditional, 9 control).

INTERVENTION(S)

Intervention groups performed supervised rehabilitation 3 d/wk for a total of 12 sessions.

MAIN OUTCOME MEASURE(S)

Time to boundary (TTB) and the Star Excursion Balance Test (SEBT) were conducted at baseline, 2 weeks, and 4 weeks. Self-reported function was measured at baseline and 4-week follow-up. Between-groups differences were compared using repeated-measures multivariate analysis of variance.

RESULTS

With the eyes open, both intervention groups improved (P < .05) in the mean and the SD of the TTB anterior-posterior minima. In the eyes-closed condition, a time main effect (P < .05) for absolute TTB medial-lateral minima was observed. A time main effect was also noted in the posteromedial and posterolateral reach directions of the SEBT. When the scores for each group were pooled, improvement (P < .05) in self-reported function was demonstrated at 4-week follow-up.

CONCLUSIONS

Rehabilitation using the Wii Fit and traditional exercises improved static postural control in patients with a history of lower extremity injury.

Neuromuscular changes after aerobic exercise in people with anterior cruciate ligament-reconstructed knees

CONTEXT

Anterior cruciate ligament (ACL) reconstructions are common, especially in young, active people. The lower extremity neuromuscular adaptations seen after aerobic exercise provide information about how previously injured patients perform and highlight deficits and, hence, areas for focused treatment. Little information is available about neuromuscular performance after aerobic exercise in people with ACL reconstructions.

OBJECTIVE

To compare dynamic balance, gluteus medius muscle activation, vertical jump height, and hip muscle strength after aerobic exercise in people with ACL-reconstructed knees.

DESIGN

Case-control study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Of 34 recreationally active volunteers, 17 had a unilateral primary ACL reconstruction at least 2 years earlier and 17 were matched controls.

INTERVENTION(S)

All participants performed 20 minutes of aerobic exercise on a treadmill.

MAIN OUTCOME MEASURE(S)

We recorded dynamic, single-legged balance electromyographic gluteus medius muscle activation, single-legged vertical jump height, and maximum isometric strength for hip abduction, extension, and external rotation preexercise and postexercise.

RESULTS

Participants with ACL reconstructions exhibited shorter reach distances during dynamic balance tasks, indicating poorer dynamic balance, and less gluteus medius muscle electromyographic activation. Reductions in hip abduction and extension strength after exercise were noted in all participants; however, those with ACL reconstructions displayed greater hip extensor strength loss after aerobic exercise than did the control group.

CONCLUSIONS

Neuromuscular changes after aerobic exercise exist in both patients with ACL reconstructions and controls. The former group may experience greater deficits in hip extensor strength after aerobic exercise. Reduced reach distances in people with ACL reconstructions may represent a protective mechanism against excessive tibiofemoral rotation during dynamic balance. Clinicians should identify weaknesses in the resting state and after aerobic exercise in recreationally active patients and those with ACL reconstructions.

The assessment of postural control and the influence of a secondary task in people with anterior cruciate ligament reconstructed knees using a Nintendo Wii Balance Board

BACKGROUND

Postural control impairments may persist following anterior cruciate ligament (ACL) reconstruction. The effect of a secondary task on postural control has, however, not been determined. The purpose of this case-control study was to compare postural control in patients following ACL reconstruction with healthy individuals with and without a secondary task.

PARTICIPANTS

45 patients (30 men and 15 women) participated at least 6 months following primary ACL reconstruction surgery. Participants were individually matched by age, gender and sports activity to healthy controls.

MATERIALS

Postural control was measured using a Nintendo Wii Balance Board and customised software during static single-leg stance and with the addition of a secondary task. The secondary task required participants to match the movement of an oscillating marker by adducting and abducting their arm.

MAIN OUTCOME MEASURES

Centre of pressure (CoP) path length in both medial-lateral and anterior-posterior directions, and CoP total path length.

RESULTS

When compared with the control group, the anterior-posterior path length significantly increased in the ACL reconstruction patients' operated (12.3%, p=0.02) and non-operated limbs (12.8%, p=0.02) for the single-task condition, and the non-operated limb (11.5%, p=0.006) for the secondary task condition. The addition of a secondary task significantly increased CoP path lengths in all measures (p<0.001), although the magnitude of the increase was similar in both the ACL reconstruction and control groups.

DISCUSSION

ACL reconstruction patients showed a reduced ability in both limbs to control the movement of the body in the anterior-posterior direction. The secondary task affected postural control by comparable amounts in patients after ACL reconstruction and healthy controls. Devices for the objective measurement of postural control, such as the one used in this study, may help clinicians to more accurately identify patients with deficits who may benefit from targeted neuromuscular training programs.

Static and dynamic postural control in competitive athletes after anterior cruciate ligament reconstruction and controls

PURPOSE

To evaluate the test-retest reliability and compare the static and dynamic postural control values in competitive athletes following anterior cruciate ligament (ACL) reconstruction and controls.

METHODS

Thirty athletes, 8.4 ± 1.8 months after ACL reconstruction, and thirty healthy matched controls were asked to execute single-leg stance and single-legged drop jump tests onto a force plate. Amplitude and velocity in anteroposterior and mediolateral directions, and mean total velocity were measured for static evaluation. Peak vertical ground reaction force (PVGRF) during landing and takeoff and loading rate were measured for dynamic evaluation. To evaluate test-retest reliability, 15 participants of each group repeated the tests 6-8 days after the first session. Mixed model of analysis of variance was used to determine differences between the involved, uninvolved, and control limbs. The test-retest reliability was measured using intraclass correlation coefficient and standard error of measurement.

RESULTS

Greater postural sway has been observed in the operated leg of ACL-reconstructed athletes compared with the non-operated side (P < 0.01) and the matched limb of the control group (P < 0.01). During landing, PVGRF and loading rate on the uninvolved limb of the athletes who had undergone ACL reconstruction were greater in comparison with those of the control group (P < 0.001). Both static and dynamic postural measures have high test-retest reliability, ranging from 0.73 to 0.88.

CONCLUSIONS

Static and dynamic postural measures are reliable tests to evaluate functional performance of athletes following ACL reconstruction. Eight months postsurgery, competitive athletes still demonstrated postural asymmetries, compared to matched controls, which might result in their susceptibility to future ACL injury.

LEVEL OF EVIDENCE

Prognostic study, case-control, Level III.

Neuromuscular training for rehabilitation of sports injuries: a systematic review

PURPOSE

Although proprioceptive and neuromuscular exercises are considered to be part and parcel of rehabilitation programs after sport injuries, there is an uncertainty regarding the effectiveness of corresponding training interventions. The objective of this review was to evaluate the effectiveness of proprioceptive and neuromuscular training (PT/NT) for the treatment of ankle, knee, and shoulder joint injuries.

METHODS

Two independent reviewers performed a literature search in various databases and reference lists of articles. Data of included trials were then extracted, and methodological quality was assessed by using predetermined forms.

RESULTS

Fifteen trials met the inclusion criteria. PT/NT was effective at increasing functionality as well as at decreasing the incidence of recurrent injuries and "giving way" episodes after ankle sprains and in conservative treatment of anterior cruciate ligament injuries. However, conflicting results or no efficacy of training were reported for static postural control, joint position sense, neuromuscular control, joint laxity, and lower extremity strength. No study that examined PT/NT after shoulder injuries was found.

CONCLUSIONS

From this review, it can be concluded that proprioceptive and neuromuscular interventions after ankle and knee joint injuries can be effective for the prevention of recurrent injuries and the improvement of joint functionality.

Physiotherapy-guided versus home-based, unsupervised rehabilitation in isolated anterior cruciate injuries following surgical reconstruction

PURPOSE

The aim of this study was to investigate the outcome after ACL reconstruction between a group of patients receiving a standardized, supervised, physiotherapy-guided rehabilitation programme and a group of patients who followed an unsupervised, home-based rehabilitation programme.

METHODS

Forty patients with isolated anterior cruciate ligament injuries were allocated to either a supervised physiotherapy intervention group or home-based exercise group. Patients were investigated by an independent examiner pre-operative, 3, 6, 9 and 12 months post-surgery using the following outcome measures: Lysholm Score and Tegner Activity Scale, functional hopping tests, and isometric and isokinetic strength assessments.

RESULTS

Both groups improved significantly (P = 0.01-0.04) following 12 months after surgery. The median Lysholm score increased from 57 (34-90) to 94 (90-100) in the supervised group and 60 (41-87) to 97 (95-100) in the unsupervised group. The median Tegner Activity Scale increased from 3 (2-8) to 6 (3-8) in the supervised group and 4 (2-8) to 5 (3-10) in the unsupervised group. The combined mean symmetry indices for the hopping tests improved from 77.3 ± 18.7 to 86.8 ± 11.1 (supervised) and from 78.1 ± 30.5 to 88.3 ± 10.9 (unsupervised). Isometric and isokinetic strength symmetry indices for knee extension improved from 68.9 ± 23.5 to 82.8 ± 11.9, respectively, 63.7 + 22.8 to 82.7 + 15.1 in the supervised group and from 73.6 ± 20.5 to 76.5 ± 17.9, respectively, 69.5 ± 24.3 to 76.9 ± 16.9 in the unsupervised group. Eccentric strength symmetry indices for knee extension improved from 67.9 ± 27.7 to 87.8 ± 6.8 in the supervised group and from 71.3 ± 17.8 to 82.6 ± 15.6 in the unsupervised group.

CONCLUSION

This study could not demonstrate a benefit in a rehabilitation programme supervised by a physiotherapist in our population compared to an unsupervised cohort.

Is postural control restored following anterior cruciate ligament reconstruction? A systematic review

PURPOSE

The aim of this systematic review was to determine whether lower limb postural control is restored in patients following anterior cruciate ligament (ACL) reconstruction surgery when compared to healthy controls.

METHODS

A systematic review was conducted. Electronic databases including Medline, Embase, SPORTDiscus and CINAHL were searched from the earliest possible entry to April 2010. Studies that evaluated postural control in patients following ACL reconstruction surgery with a control group using a force platform were included.

RESULTS

Ten studies evaluating 644 participants at a mean 29 months follow-up were included in this review. In static balance tasks, there was a trend towards improved postural control in the control group for eyes-open but not eyes-closed conditions. Only four studies evaluated dynamic balance, and the results from these were somewhat mixed. Nonetheless, there was evidence to suggest impaired postural control in patients following ACL reconstruction surgery when compared to controls, particularly for more challenging tasks.

CONCLUSION

Although there appears to be a trend towards impaired static and dynamic postural control in patients following ACL reconstruction surgery, the limited number of studies and differing methodologies makes conclusions tentative. Deficits in dynamic tasks may be more relevant to people intending to return to sport following surgery due to the inherently dynamic nature of sport and should perhaps be the focus of future research.

WITHDRAWN: Exercise for treating anterior cruciate ligament injuries in combination with collateral ligament and meniscal damage of the knee in adults

BACKGROUND

The anterior cruciate ligament (ACL) is the most frequently injured ligament of the knee. The ACL may be damaged in isolation but often other ligaments and menisci are implicated. The injury may be managed surgically or conservatively. Injury causes pain, effusion and inflammation leading to alteration in muscle function. Regaining muscular control is essential if the individual wishes to return to pre-injury level of function and patients will invariably be referred for rehabilitation.

OBJECTIVES

To present the best evidence for effectiveness of exercise used in the treatment of ACL injuries in combination with collateral ligament and meniscal damage to the knee in adults, on return to work and pre-injury levels of activity.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (October 2006), Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, Issue 3), MEDLINE (1996 to October 2006), EMBASE (1980 to October 2006), other databases and reference lists of articles.

SELECTION CRITERIA

We included randomised controlled trials and quasi-randomised trials testing exercise programmes designed to treat adults with ACL injuries in combination with collateral ligament and meniscal damage. Included trials randomised participants to receive any combination of the following: no care, usual care, a single-exercise intervention, and multiple-exercise interventions. The primary outcome measures of interest were returning to work and return to pre-injury level of activity post treatment, at six months and one year.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

Five trials (243 participants) evaluated different exercise programmes following ACL reconstruction and one trial (100 participants) compared supervised with self-monitored exercises as part of conservative treatment. No study compared the effect of exercise versus no exercise. Methodological quality scores varied considerably across the trials; participant and assessor blinding were poorly reported. Pooling of data was rarely possible due to the wide variety of comparisons, outcome measures and time points reported, and lack of appropriate data. Insufficient evidence was found to support the efficacy of one exercise intervention over another.

AUTHORS' CONCLUSIONS

This review has demonstrated an absence of evidence to support one form of exercise intervention over another. Further research should be considered in the form of large scale well-designed and well-reported randomised controlled trials with suitable outcome measures and surveillance periods. Suitable outcome measures should include a measure of functional outcome relevant to the individual.

WITHDRAWN: Exercise for treating isolated anterior cruciate ligament injuries in adults

BACKGROUND

The anterior cruciate ligament (ACL) is the most frequently injured ligament of the knee. Injury causes pain, effusion and inflammation leading to the inability to fully activate the thigh muscles. Regaining muscular control is essential if the individual wishes to return to pre-injury level of function and patients will invariably be referred for rehabilitation.

OBJECTIVES

To present the best evidence for effectiveness of exercise used in the rehabilitation of isolated ACL injuries in adults, on return to work and pre-injury levels of activity.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (Feb 2005), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2005), MEDLINE (1996 to March 2005), EMBASE (1980 to March 2005), other databases and reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised trials testing exercise programmes designed to rehabilitate adults with isolated ACL injuries. Trials where participants were randomised to receive any combination of the following: no care, usual care, a single-exercise intervention, and multiple-exercise interventions, were included. The primary outcome measures of interest were returning to work and return to pre-injury level of activity post treatment, at six months and one year.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

Nine trials involving 391 participants were included. Only two trials, involving 76 participants, reported conservative rehabilitation and seven trials, involving 315 participants, evaluated rehabilitation following ACL reconstruction. Methodological quality scores varied considerably across the trials, with the nature of participant and assessor blinding poorly reported. Trial comparisons fell into six categories. Pooling of data was rarely possible due to lack of appropriate data as well as the wide variety in outcome measures and time points reported. Insufficient evidence was found to support the efficacy of one exercise intervention over another.

AUTHORS' CONCLUSIONS

This review has demonstrated an absence of evidence to support one form of exercise intervention against another and the use of supplementary exercises in the management of isolated ACL injuries. Further research in the form of large scale well designed randomised controlled trials with suitable outcome measures and surveillance periods, using standardised reporting should be considered.

Balance training for neuromuscular control and performance enhancement: a systematic review

OBJECTIVE

As a result of inconsistencies in reported findings, controversy exists regarding the effectiveness of balance training for improving functional performance and neuromuscular control. Thus, its practical benefit in athletic training remains inconclusive. Our objective was to evaluate the effectiveness of training interventions in enhancing neuromuscular control and functional performance.

DATA SOURCES

Two independent reviewers performed a literature search in Cochrane Bone, Joint and Muscle Trauma Group Register and Cochrane Controlled Trials Register, MEDLINE, EMBASE, PEDro (Physiotherapy Evidence Database), and SCOPUS.

STUDY SELECTION

Randomized controlled trials and controlled trials without randomization with healthy and physically active participants aged up to 40 years old were considered for inclusion. Outcomes of interest were postural control, muscle strength, agility, jump performance, sprint performance, muscle reflex activity, rate of force development, reaction time, and electromyography.

DATA EXTRACTION

Data of interest were methodologic assessment, training intervention, outcome, timing of the outcome assessment, and results. Standardized mean differences and 95% confidence intervals were calculated when data were sufficient.

DATA SYNTHESIS

In total, 20 randomized clinical trials met the inclusion criteria. Balance training was effective in improving postural sway and functional balance when compared with untrained control participants. Larger effect sizes were shown for training programs of longer duration. Although controversial findings were reported for jumping performance, agility, and neuromuscular control, there are indications for the effectiveness of balance training in these outcomes. When compared with plyometric or strength training, conflicting results or no effects of balance training were reported for strength improvements and changes in sprint performance.

CONCLUSIONS

We conclude that balance training can be effective for postural and neuromuscular control improvements. However, as a result of the low methodologic quality and training differences, further research is strongly recommended.