Evaluating the center of gravity of dislocations in soccer players with and without reconstruction of the anterior cruciate ligament using a balance platform

Clinical Outcomes After ACL Reconstruction in Soccer (Football, Futbol) Players: A Systematic Review and Meta-Analysis

CONTEXT

The risk factors for anterior cruciate ligament (ACL) tear for athletes participating in pivoting sports includes young age and female sex. A previous meta-analysis has reported a reinjury rate of 15% after ACL reconstruction (ACLR) for athletes across all sports. To the best of the authors' knowledge, this is the first systematic review and meta-analysis of available literature reporting outcomes after ACLR in soccer players.

OBJECTIVE

To review and aggregate soccer-specific outcomes data after ACLR found in current literature to help guide a more tailored discussion regarding expectations and prognosis for soccer players seeking operative management of ACL injuries.

DATA SOURCES

A comprehensive search of publications was performed using PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SPORTDiscus databases.

STUDY SELECTION

Inclusion criteria consisted of original studies, level of evidence 1 to 4, studies reporting clinical and patient-reported outcomes (PROs) after primary ACLR in soccer players at all follow-up length.

STUDY DESIGN

The primary outcomes of interest were graft failure/reoperation rates, ACL injury in contralateral knee, return to soccer time, and PROs.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Search of literature yielded 32 studies for inclusion that involved 3112 soccer players after ACLR.

RESULTS

The overall graft failure/reoperation rate ranged between 3.0% and 24.8% (mean follow-up range, 2.3-10 years) and the combined ACL graft failure and contralateral ACL injury rate after initial ACLR was 1.0% to 16.7% (mean follow-up range, 3-10 years); a subgroup analysis for female and male players revealed a secondary ACL injury incidence rate of 27%, 95% CI (22%, 32%) and 10%, 95% CI (6%, 15%), respectively. Soccer players were able to return to play between 6.1 and 11.1 months and the majority of PROs showed favorable scores at medium-term follow-up.

CONCLUSION

Soccer players experience high ACL injury rates after primary ACLR and demonstrated similar reinjury rates as found in previous literature of athletes who participate in high-demand pivoting sports.

Kinetic measurement system use in individuals following anterior cruciate ligament reconstruction: a scoping review of methodological approaches

Purpose

Our primary objectives were to (1) describe current approaches for kinetic measurements in individuals following anterior cruciate ligament reconstruction (ACLR) and (2) suggest considerations for methodological reporting. Secondarily, we explored the relationship between kinetic measurement system findings and patient-reported outcome measures (PROMs).

Methods

We followed the PRISMA extension for scoping reviews and Arksey and O’Malley’s 6-stage framework. Seven electronic databases were systematically searched from inception to June 2020. Original research papers reporting parameters measured by kinetic measurement systems in individuals at least 6-months post primary ACLR were included.

Results

In 158 included studies, 7 kinetic measurement systems (force plates, balance platforms, pressure mats, force-measuring treadmills, Wii balance boards, contact mats connected to jump systems, and single-sensor insoles) were identified 4 main movement categories (landing/jumping, standing balance, gait, and other functional tasks). Substantial heterogeneity was noted in the methods used and outcomes assessed; this review highlighted common methodological reporting gaps for essential items related to movement tasks, kinetic system features, justification and operationalization of selected outcome parameters, participant preparation, and testing protocol details. Accordingly, we suggest considerations for methodological reporting in future research. Only 6 studies included PROMs with inconsistency in the reported parameters and/or PROMs.

Conclusion

Clear and accurate reporting is vital to facilitate cross-study comparisons and improve the clinical application of kinetic measurement systems after ACLR. Based on the current evidence, we suggest methodological considerations to guide reporting in future research. Future studies are needed to examine potential correlations between kinetic parameters and PROMs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40634-021-00397-0.

The dominant leg is more likely to get injured in soccer players: systematic review and meta-analysis

In soccer (football), dominant limb kicking produces higher ball velocity and is used with greater frequency than the non-dominant limb. It is unclear whether limb dominance has an effect on injury incidence. The purpose of this systematic review with meta-analysis is to examine the relationship between limb dominance and soccer injuries. Studies were identified from four online databases according to PRISMA guidelines to identify studies of soccer players that reported lower extremity injuries by limb dominance. Relevant studies were assessed for inclusion and retained. Data from retained studies underwent meta-analyses to determine relative risk of dominant versus non-dominant limb injuries using random-effects models. Seventy-four studies were included, with 36 of them eligible for meta-analysis. For prospective lower extremity injury studies, soccer players demonstrated a 1.6 times greater risk of injury to the dominant limb (95% CI [1.3-1.8]). Grouped by injury location, hamstring (RR 1.3 [95% CI 1.1-1.4]) and hip/groin (RR 1.9 [95% CI 1.3-2.7]) injuries were more likely to occur to the dominant limb. Greater risk of injury was present in the dominant limb across playing levels (amateurs RR 2.6 [95% CI 2.1-3.2]; youths RR 1.5 [95% CI 1.26-1.67]; professionals RR 1.3 [95% CI 1.14-1.46]). Both males (RR 1.5 [95% CI 1.33-1.68)] and females (RR 1.5 [95% CI 1.14-1.89]) were more likely to sustain injuries to the dominant limb. Future studies investigating soccer injury should adjust for this confounding factor by using consistent methods for assigning limb dominance and tracking use of the dominant versus non-dominant limb.

The Consequences of Glaucoma on Mobility and Balance Control in the Older Adults: A Cross-Sectional Study

The aim of the study was to explore the functional impairments and related factors in older adults with moderate to advanced stages of glaucoma. Nineteen patients with glaucoma and 19 participants with no ocular disease performed step test and balance control tasks with analysis of overall stability index and fall risk index. Monocular and binocular Humphrey Visual Field tests were used to estimate visual field defect severity. The International Physical Activity Questionnaire was used to measure physical activity level. Patients with glaucoma showed poorer values for most of the mobility and balance control parameters with medium and large effect sizes (0.3-0.5). Mobility scores in patients were partly associated with their monocular visual field defect (rs = .507, p < .05). Low physical activity was identified as a risk factor for falls (rs = -.453, p < .05) and postural instability (rs = -.457, p < .05). Functional declines in dynamic tasks were not related to glaucoma severity. Older adults with glaucoma display impairment with mobility and balance control compared to controls, associated with the degree of monocular visual field loss and lower daily physical activity.

Alterations in medial-lateral postural control after anterior cruciate ligament reconstruction during stair use

BACKGROUND

Dynamic postural control during everyday tasks is poorly understood in people following anterior cruciate ligament reconstruction (ACLR). Understanding dynamic postural control can provide insight into potentially modifiable impairments in people following ACLR who are at increased risk for second ACL injury and/or knee osteoarthritis.

RESEARCH QUESTION

Determine whether measures indicative of dynamic postural control differ between individuals with and without ACLR during stair ascent and descent.

METHODS

Seventeen individuals with ACLR (>1 yr post-surgery) and 16 age and sex-matched healthy controls participated. Centre of pressure (COP) measures included: i) COP excursion, ii) COP velocity, and iii) dynamic time-toboundary (TTB). Mixed linear models were used to compare COP measures for the ACLR leg, non-ACLR leg, and healthy controls during stair ascent and stair descent.

RESULTS

There were no statistically significant differences observed during stair ascent (all p > 0.05). Several statistical differences were found during stair descent for individual with ACLR, but not between those with ACLR and healthy controls. The ACLR leg had higher medial-lateral COP excursion (mean difference 1.06 cm, [95 %CI 0.08-2.06 cm], p = 0.036; effect size = 0.38) compared to the non-ACLR leg during stair descent. In addition, the ACLR leg had a lower medial-lateral TTB (mean difference -13 ms [95 %CI -38 to 2 ms], p = 0.005; effect size = 0.49) and medial-lateral TTB normalized to stance time (mean difference -5.8 % [95 %CI -10.3 to 1.3 %], p = 0.012; effect size = 0.80) compared to the non-ACLR leg during stair descent. No statistical differences were observed for anterior-posterior measures during stair descent (all p > 0.05).

SIGNIFICANCE

Taken together, findings indicate that there are small to large differences in medial-lateral postural control in the ACLR leg compared to the non-ACLR leg during stair descent. Further work is required to understand clinical implication of these novel observations.

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.

Evaluation of static and dynamic balance in athletes with anterior cruciate ligament injury - A controlled study

OBJECTIVES

Anterior cruciate ligament injury leads to adaptive responses to maintain postural control. However, there is no consensus regarding whether leg dominance also affects postural control in athletes with anterior cruciate ligament injury. The purpose of this study was to evaluate dynamic and static postural control among athletes with and without anterior cruciate ligament injury to the dominant leg.

METHODS

Twenty-eight athletes, twenty-one males and seven females aged 15-45 years, were allocated to one of two groups: the anterior cruciate ligament injury group (26±3 years) or the control group without anterior cruciate ligament injury (25±6.5 years). All subjects performed one legged stance tests under eyes open and eyes closed conditions and squat and kick movement tests using a postural control protocol (AccuSwayPlus force platform, Massachusetts). The center of pressure displacement and speed were measured by the force platform. In addition, the distance traveled on the single-leg hop test was assessed as an objective measure of function.

RESULTS

Significantly greater mediolateral sway was found under the eyes closed condition (p=0.04) and during squat movement (p=0.01) in the anterior cruciate ligament injury group than in the control group. Analysis of the single-leg hop test results showed no difference between the groups (p=0.73).

CONCLUSION

Athletes with anterior cruciate ligament injury had greater mediolateral displacement of the center of pressure toward the dominant leg under the eyes closed condition and during squat movement compared to control athletes.

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.

Characteristics of Autocorrelation Structure of Lower Extremity Functional Laterality in Disturbed and Undisturbed Bipedal Upright Stance

Purpose. It is posited that functional laterality is influenced by the generation and conduction of neural signals and therefore associated with sensorimotor control. The question arises if symmetry or asymmetry in sensorimotor processing affects the development of symmetric or asymmetric motor programs in the lower extremities. The purpose of the study was to examine the mechanisms of the human mobility moto-control - the process of maintaining body balance in a standing position through an appropriate course of distribution of ground reaction forces in a time frame, in a situation requiring lower extremity movement symmetry. Methods. The autocorrelation function was calculated for ground reaction forces (in the three orthogonal axes) registered during 45 s of bipedal upright stance in two conditions (eyes open and closed). Results. Minor albeit significant deficiencies in postural muscle control were revealed as a function of time, as evidenced in the decay of the autocorrelation function to zero (T

Reliability of dynamic balance simultaneously with cognitive performance in patients with ACL deficiency and after ACL reconstructions and in healthy controls

PURPOSE

To determine the intra- and inter-session reliability of balance and cognitive performance in anterior cruciate ligament-deficient (ACLD) and ACL-reconstructed (ACLR) and matched athletes.

METHODS

Using SMART EquiTest, recovery reactions of the groups were assessed during single-leg standing, following medium and large forward perturbations with and without performing a cognitive (Stroop) task. The outcomes included reaction time (RT), latency and amplitude for balance and error ratio (ER) and RT for cognitive performance. The participants of each group repeated the tests 2-7 days after the first session. Intraclass correlation coefficient (ICC) and standard error of measurement were computed in order to assess relative and absolute reliability, respectively.

RESULTS

Single- and dual-task balance measures had moderate to very high reliability in ACLD (ICC = 0.63-0.88), ACLR (ICC = 0.62-0.93) and control (ICC = 0.69-0.98) athletes. The ICCs for RT of Stroop were between 0.87 and 0.90 in ACLD, between 0.70 and 0.74 in ACLR and between 0.66 and 0.70 in controls and for ER of Stroop were between 0.36 and 0.90 in ACLD, between 0.42 and 0.49 in ACLR and between 0.41 and 0.51 in controls.

CONCLUSIONS

Balance measures and RT of the cognitive task in single- and dual-task conditions have acceptable reliability and may be incorporated into the evaluation of physical and mental function of athletes following ACL injury and reconstruction. ER of the cognitive task is less reliable which needs to be considered in future research.

LEVEL OF EVIDENCE

Prognostic study, case-control, Level III.

Postural stability in patients with anterior cruciate ligament tears with and without medial meniscus tears

PURPOSE

To compare postural stability in patients with isolated anterior cruciate ligament (ACL) tears and ACL tears with associated meniscal tears.

METHODS

Quadriceps and hamstring muscle strength and their ratio, as well as the relationships of these parameters with postural stability, were compared in 23 patients with isolated ACL tears and 27 with combined ACL and medial meniscus tears. Postural stability was determined from the anterior-posterior, medial-lateral, and overall stability indices using the Biodex Stability System.

RESULTS

On both the involved and uninvolved sides, there were no differences in mean stability indices, including anterior-posterior, medial-lateral, and overall stability indices, in patients with isolated and combined ACL tears. In patients with isolated ACL tears, both overall (2.3 ± 1.2 vs. 1.8 ± 1.4, p = 0.033) and medial-lateral (1.2 ± 0.6 vs. 1.0 ± 0.5, p = 0.031) stability indices were significantly higher on the involved compared to the uninvolved side. These differences, however, were not observed in the combined ACL tear group.

CONCLUSION

No significant differences in postural instability on the affected and unaffected sides were observed in patients with isolated ACL tears and those with combined ACL and medial meniscus tears. These findings indicate that there is no need to reduce the goal of restoring proprioception in patients with combined compared with isolated ACL tears.

LEVEL OF EVIDENCE

III.

Comparison of the postural control between football players following ACL reconstruction and healthy subjects

BACKGROUND

Rupture of the Anterior Cruciate Ligment (ACL) is a common knee injury. The purpose of this study was to determine the balance control in football players with and without ACL reconstruction in posture of injury.

METHODS

Sway of the center of gravity of 15 patients with ACL reconstruction was compared with 15 healthy, age and sex-matched subjects as the control group. All tests were done unilaterally in the posture of injury, using a kistler force plate with the open and -closed eye conditions.

RESULTS

The knee of the operated side of the case group showed more displacement of the center of gravity when compared to the non-operated side in the same subject for all variables of the force plate. The operated side of the case group showed more displacement of the center of gravity for all variables of the force plate in comparison with the dominant side of knees in control group. There were significant differences between the non-operated side in the case group and the dominant side of the control group.

CONCLUSION

All together, postural control in the operated side of the case group was weaker than the nonoperated side of the same group and the dominant limb of the control group, which might have resulted from poor proprioception. The postural control was even weaker in the non-operated side of the case group as compared with the dominant limb of the control group, which can justify the hypo mobility of limb for several months after the surgery.

[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.

Altered postural sway persists after anterior cruciate ligament reconstruction and return to sport

Postural sway is defined as the movement of a body's center of mass within the base of support to maintain postural equilibrium. Deficits in postural sway are present after ACL injury; however, current evidence linking it to future injury risk is unclear. The purpose of this study was to determine if postural sway deficits persist after ACL reconstruction (ACLR). The hypothesis tested was that after ACLR, patients who return to sport (RTS) would demonstrate differences in postural sway compared to control (CTRL) subjects. Fifty-six subjects with unilateral ACLR released to RTS, and 42 uninjured CTRL subjects participated. Dynamic postural sway was assessed and 3-way (2×2×2) ANOVA was used to analyze the variables. A side×group×sex (p=0.044) interaction in postural sway was observed. A side×group analysis also revealed an interaction (p=0.04) however, no effect of sex was observed (p=0.23). Analysis within the ACLR cohort showed less (p=0.001) postural sway on the involved side (1.82±0.84°) versus the uninvolved side (2.07±0.96°). No side-to-side differences (p=0.73) were observed in the CTRL group. The involved limb of subjects after ACLR demonstrated the least postural sway. In conclusion, these findings indicate that dynamic postural sway may be significantly altered in a population of athletes after ACLR and RTS compared to CTRL subjects. Further investigation is needed to determine if deficits in postural sway can be used as an effective criterion to assist in the decision to safely RTS after ACLR.

Relationship between anthropometric factors, gender, and balance under unstable conditions in young adults

The objective of this study was to evaluate the relationship between the anthropometric factors of height, body mass, body mass index and postural balance and to compare the balance indices between genders in the upright standing position, in healthy adult subjects under conditions of instability. Forty individuals were subjected to functional tests of body stability using the Biodex Balance System, and the resulting indices were correlated with body mass, height, and body mass index, and also compared between genders. Body mass was the main anthropometric factor that influenced variations in postural balance, with a high correlation between groups and with all variables. A linear regression analysis showed that body mass associated with BMI explained 66% of the overall stability, and body mass explained 59% of the anteroposterior stability index and 65% of the mediolateral stability index. In the female group, body mass explained 72% of the overall balance, 66% of the anteroposterior, and 76% of the medio-lateral stability index. Increased body mass requires greater movements to maintain postural balance. Height and BMI presented moderate correlations with balance. Women showed less movement than men on the Biodex Balance System.

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.

Comparison of manual balance and balance board tests in healthy adults

Objective

To investigate the correlations of scores on the Timed Up and Go (TUG) test and the Single Leg Stance (SLS) test with stability scores on the Biodex Balance System (BBS) in healthy adults.

Method

The postural balance of 73 participants was measured on the TUG and SLS tests and with the Overall Stability Index (OSI) on the BBS. The participants were divided into groups by age and by times on the TUG and SLS. The correlations between TUG or SLS and OSI scores were analyzed by groups.

Results

TUG scores were significantly correlated with OSI scores in age under 65 years, TUG over 10 seconds and SLS over 30 seconds groups (level 12). TUG scores were also correlated with OSI in total (level 10) and TUG under 10 seconds groups (level 2). However, there were no significant relationships between SLS and OSI scores.

Conclusion

OSI scores on the BBS are significantly correlated with TUG scores, especially at the easy levels. According to the findings of present study, relatively easy BBS levels are considered to assess the postural balance in healthy adults.

The influence of lower-limb dominance on postural balance

CONTEXT AND OBJECTIVE

Maintainance of postural balance requires detection of body movements, integration of sensory information in the central nervous system and an appropriate motor response. The purpose of this study was to evaluate whether lower-limb dominance has an influence on postural balance.

DESIGN AND SETTING

This was a cross-sectional study conducted at Faculdade de Medicina da Universidade de São Paulo (FMUSP) and at Hospital do Coração (HCor).

METHODS

Forty healthy sedentary males aged 20 to 40 years, without any injuries, were evaluated. A single-foot balance test was carried out using the Biodex Balance System equipment, comparing the dominant leg with the nondominant leg of the same individual. The instability protocols used were level 8 (more stable) and level 2 (less stable), and three instability indices were calculated: anteroposterior, mediolateral and general.

RESULTS

The volunteers' mean age was 26 ± 5 years (range: 20-38), mean weight 72.3 ± 11 kg (range: 46-107) and mean height 176 ± 6 cm (range: 169-186). Thirty-four of them (85%) presented right-leg dominance (defined according to which leg they used for kicking) and six (15%) had left-leg dominance. There were no significant differences between the dominant and nondominant legs at the two levels of stability (eight and two), for any of the instability indices (general, anteroposterior and mediolateral).

CONCLUSION

The lower-limb dominance did not influence single-foot balance among sedentary males.

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.

Estudo de publicações em periódicos gerais de artigos sobre ortopedia e aparelho locomotor

Os autores estudam o perfil de publicação de artigos sobre ortopedia e área de interesse em aparelho locomotor em revistas gerais, não específicas de ortopedia, com registro no PUBMED, em um período de dois anos. Selecionados 67 artigos com distribuição heterogênea entre as revistas estudadas foi constatada presença de 26,47% de artigos com desenho de intervenção e 38% com desenho observacional. Os dados são comentados.

The Brazilian Football Association (CBF) model for epidemiological studies on professional soccer player injuries

OBJECTIVE

This study aims to establish a national methodological model for epidemiological studies on professional soccer player injuries and to describe the numerous relevant studies previously published on this topic.

INTRODUCTION

The risk of injury in professional soccer is high. However, previous studies of injury risk in Brazil and other countries have been characterized by large variations in study design and data collection methods as well as definitions of injury, standardized diagnostic criteria, and recovery times.

METHODS

A system developed by the Union of European Football for epidemiological studies on professional soccer players is being used as a starting point to create a methodological model for the Brazilian Football Association. To describe the existing studies on professional soccer player injuries, we developed a search strategy to identify relevant epidemiological studies. We included the Latin American and Caribbean Center on Health Sciences and Medline databases in our study.

RESULTS

We considered 60 studies from Medline and 16 studies from the Latin American and Caribbean Center on Health Sciences in the final analysis. Twelve studies were selected for final inclusion in this review: seven from the Latin American and Caribbean Center on Health Sciences and five from Medline. We identified a lack of uniformity in the study design, data collection methods, injury definitions, standardized diagnostic criteria, and the definition of recovery time. Based on the information contained within these articles, we developed a model for epidemiological studies for the Brazilian Football Association.

CONCLUSIONS

There is no uniform model for epidemiological studies of professional soccer injuries. Here, we propose a novel model to be applied for epidemiological studies of professional soccer player injuries in Brazil and throughout the world.

Desempenho do membro não-acometido em pacientes com reconstrução do ligamento cruzado anterior

Défices sensoriais persistentes após a reconstrução do ligamento cruzado anterior (LCA) podem causar alterações como fraqueza muscular e comprometimento do equilíbrio e do desempenho funcional. Diversos estudos discutem se essas alterações também estão presentes no membro inferior não-acometido e se esse membro pode ser utilizado como referência nas avaliações desses pacientes. O objetivo do presente estudo foi comparar o torque extensor e flexor do joelho, o equilíbrio unipodal e o desempenho funcional sobre o membro não-acometido de pacientes submetidos à reconstrução do LCA, com membros inferiores de sujeitos saudáveis. Participaram do estudo 23 indivíduos submetidos à reconstrução do LCA e 22 sujeitos saudáveis, que foram avaliados quanto ao torque extensor e flexor do joelho durante contração isocinética concêntrica a 60 graus/s no dinamômetro isocinético, à velocidade média de oscilação do centro de pressão em apoio unipodal no baropodômetro, e submetidos a dois testes de salto para avaliar o desempenho funcional. Os resultados não revelaram diferenças entre o membro não-acometido e os membros inferiores do grupo controle em todas as variáveis estudadas (p>0,05). Esses resultados sugerem que o membro não-acometido de pacientes submetidos à reconstrução do LCA pode ser utilizado como referência nos estudos de avaliação desses pacientes.