The effect of short-duration sub-maximal cycling on balance in single-limb stance in patients with anterior cruciate ligament injury: a cross-sectional study

The Effect of Contralateral Knee Neuromuscular Exercises on Static and Dynamic Balance, Knee Function, and Pain in Athletes Who Underwent Anterior Cruciate Ligament Reconstruction: A Single-Blind Randomized Controlled Trial

CONTEXT

Contralateral training in the early stages after surgery can improve the balance of the reconstructed knee, which is impaired following anterior cruciate ligament reconstruction (ACLR). However, little is known about the neuromuscular cross exercise after ACLR.

OBJECTIVE

To investigate the effects of an 8-week cross exercise on balance and function of the reconstructed knee following ACLR.

DESIGN

A single-blind randomized clinical trial.

PARTICIPANTS

Thirty athletic males who underwent ACLR were randomly divided into intervention (n = 15) and control groups (n = 15).

INTERVENTION

The intervention and control groups received a routine physiotherapy program. In addition, the intervention group performed neuromuscular exercises on the nonoperated limb.

OUTCOME MEASURES

Before and 9 weeks after ACLR, dynamic and static balance, function, and pain in the reconstructed knee were measured by Star Excursion Balance Test (SEBT), stork balance stand test, balance error scoring system (BESS), Lysholm questionnaire, and visual analog scale. Data were analyzed by SPSS using 2-independent sample t test, paired t test, and analysis of covariance.

RESULTS

Between-group comparison showed that, contralateral knee neuromuscular exercises significantly increased in the reaching distance in SEBT in the anterior (P < .001), posterior (P < .001), posteromedial (P = .010), and posterolateral directions (P = .007), decreased the number of errors in 4 stance positions of BESS including single stance on the firm (P ≤ .001) and foam surface (P ≤ .001), and tandem stance on the firm (P = .028) and foam surface (P ≤ .001). It also increased the time of standing of the stork stand test (P = .044) and decreased the pain intensity (P = .014).

CONCLUSION

Neuromuscular exercise of the nonsurgical knee could improve the dynamic and static balance, and pain in the early stages following ACLR in the surgical leg. These findings may be potentially valuable for current rehabilitation protocols.

Postural control during single leg stance in individuals with clinical indication for combined reconstruction of the anterior cruciate and the anterolateral ligaments of the knee: a cross-sectional study

BACKGROUND

Several studies have shown persistent postural control deficits and rotatory instability in patients after isolated Anterior Cruciate Ligament (ACL) reconstruction. There is evidence to support that the Anterolateral Ligament (ALL) plays an important role in the remaining anterolateral rotatory laxity of the knee. There are no further evidences in order to understand how patients with a combined ACL + ALL reconstruction surgery indication behave regarding postural control. The aim of this cross-sectional study was to assess if patients with a clinical indication for the combined ACL + ALL surgery showed a deficient postural control in single leg stance compared to subjects with a regular ACL reconstruction indication and to a control group.

METHODS

An assessment of static postural control on single leg stance was performed on a force plate, with eyes open and closed, and the center of pressure (COP) displacement variables were analyzed: maximum and mean amplitude in anteroposterior (AP) and in mediolateral (ML) direction; mean velocity of displacement and area of displacement. Eighty-nine male individuals participated and were divided into 3 groups: ACL Group, ACL + ALL Group and Control Group.

RESULTS

The ACL+ ALL Group showed significantly greater COP displacement in most variables in the injured leg for the eyes closed test, compared to the ACL Group, as detailed: Total ML displacement (9.8 ± 6.77 vs. 13.98 ± 6.64, p < 0.001); Mean ML displacement (2.58 ± 2.02 vs. 3.72 ± 1.99, p < 0.001); Total AP displacement (9.5 ± 3.97 vs. 11.7 ± 3.66, p = 0.001); Mean AP displacement (1.77 ± 0.87 vs. 2.27 ± 0.86, p = 0.001); Area of displacement (111.44 ± 127.3 vs. 183.69 ± 131.48, p < 0.001).

CONCLUSION

Subjects with a clinical indication for ACL + ALL combined reconstruction surgery showed increased COP displacement compared to patients with indication for an ACL isolated reconstruction surgery.

Effect of Acute Effort on Isometric Strength and Body Balance: Trained vs. Untrained Paradigm

Years of training in competitive sports leads to human body adaptation to a specific type of exercise. In judo bouts, maintaining hand grip on an opponent’s clothes and postural balance is essential for the effective technical and tactical actions. This study compares changes after maximal anaerobic exercise among judo athletes and untrained subjects regarding 1) maximum isometric handgrip strength (HGSmax) and accuracy at the perceived 50% maximum handgrip force (1/2HGSmax) and 2) the balance of 13 judo athletes at national (n = 8) and international (n = 5) competitive levels and 19 untrained university students. The groups did not differ in age, body height, and weight. Body mass index (BMI) and body composition (JAWON) were evaluated. The Wingate Anaerobic Test (WAnT, Monark 875E) measured recommended anaerobic capacity indices. Hand grip strength (Takei dynamometer) and balance (biplate balance platform) were measured before warm-up (T1), before the WAnT test (T2), and after (T3). Parametric or non-parametric tests were performed after verifying the variable distribution assumption. Judoists had higher BMI and fat-free mass index (FFMI) than the students. The athletes also showed higher relative total work and relative peak power and lower levels of lactic acid. The difference in judoists between HGSmax at T1 and HGSmax at T3 was statistically significant. Before warm-up (T1), athletes showed higher strength (more divergent from the calculated ½HGSmax value) compared to students. Substantial fatigue after the WAnT test significantly deteriorated the body stability indices, which were significantly better in judo athletes at all time points. The findings suggest specific body adaptations in judoists, especially for body composition, anaerobic energy system efficiency, and postural balance. These characteristics could be trained for specifically by judo athletes to meet the time-motion and anaerobic demands of contemporary bouts.

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.

A systematic review of postural control during single-leg stance in patients with untreated anterior cruciate ligament injury

PURPOSE

The aim of this review was to determine whether postural control is impaired in patients with anterior cruciate ligament (ACL) injury as compared to healthy controls.

METHODS

The relevant papers were retrieved through electronic databases including PubMed, EMBASE, Web of Science, and Sport Discus followed by hand search and contact with the authors. Studies that evaluated static postural control during single-leg stance without applying external perturbations were included. Also, the patients should not have undergone ACL reconstruction or any surgical repair on the injured knee.

RESULTS

In total, 12 studies were selected for full review. The included studies showed larger postural sway amplitudes or velocities during single-leg stance on the injured leg and the uninjured leg when compared to healthy controls with medium to large effect size. Also, no significant difference was found between the injured and uninjured legs of ACL-injured patients during eyes open condition in all studies supported by small effect size. However, the within-group difference was found to be significant during eyes closed condition, with injured leg displaying larger sway.

CONCLUSIONS

The present review indicates that postural control is impaired in both legs, especially injured leg. The result of within-group difference in eyes open condition confirms bilateral deficit of postural control. However, the within-group difference during eyes closed condition indicates again that ACL injury affects the injured leg more than the uninjured leg. In designing rehabilitation protocols, clinicians should consider training postural control of not just the injured but also the uninjured leg.

Altered force ratio in unanticipated side jumps after treadmill run

OBJECTIVE

The aim was to investigate the influence of a run at the individual anaerobic threshold (IAT) on postural control in jumps with an unanticipated change of direction.

HYPOTHESIS

Dynamic postural control is less affected by the run in trained athletes than in recreational ones.

DESIGN

: Controlled prospective cohort study with an intervention.

SETTING

Biomechanics laboratory.

PARTICIPANTS

A total of 18 female high-level handball and volleyball players, 16 female and 8 male recreational athletes, with a mean age of 21.7 +/-4.1 years.

INTERVENTIONS

In the jump test, the ball switch, hit above the force plate during a forward jump, triggers indicator lamps on either side. After landing on the dominant leg, a second jump 90 degrees sideways following a light signal or a stabilization in one-leg stance was required. Nine jumps (randomized order) were performed before and at 1, 5, 10, 15 and 20 min after a 30-min treadmill run at the IAT.

MAIN OUTCOME MEASUREMENTS

For the second jump, the ratio of the absolute values of the maximum forces in anteroposterior and mediolateral direction was calculated as a parameter of dynamic postural control in the change of direction.

RESULTS

In both groups, the force ratio increased significantly at 1 and 5 min after the treadmill run. The relative increase did not differ between groups. Dynamic postural control in transfer from a forward to a sideward jump was reduced after the run. Recovery occurred within 10 min.

CONCLUSIONS

This study shows that dynamic postural control in jumps with an unanticipated change of direction is influenced by fatigue. These findings could be used to develop training programs aimed at reducing lower limb injuries in high-level ball sport athletes. The preventive effects have to be evaluated in further studies.

Balance in single-limb stance in patients with anterior cruciate ligament injury: relation to knee laxity, proprioception, muscle strength, and subjective function

BACKGROUND

It has been shown previously that an anterior cruciate ligament injury may affect postural control, measured by balance in single-limb stance. To our knowledge, no studies have reported the influence of measures of impairment on postural control after such an injury.

PURPOSE

To assess the influence of knee laxity, proprioception, and muscle strength on balance in single-limb stance and to study the correlation between balance in single-limb stance and subjective estimation of extremity function.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 36 patients with a unilateral, nonoperated, nonacute anterior cruciate ligament injury were examined with regard to anterior knee laxity, proprioception, muscle strength, and stabilometry (amplitude and average speed of the center of pressure movements). Subjective estimation of extremity function was measured on a visual analog scale.

RESULTS

The multiple regression analysis showed that high knee laxity values were associated with high amplitude values and low average speed. Poor proprioception and high muscle strength values were associated with low average speed among the women only. Low amplitude values correlated with better subjective function.

CONCLUSION

Anterior knee laxity, proprioception, and muscle strength seem to play a role in maintaining balance in single-limb stance. Patients with low amplitude values in stabilometry were those with better subjective function.