Interlimb Symmetry Research Articles

Remote Gait Analysis Using Ultra-Wideband Radar Technology Based on Joint Range-Doppler-Time Representation.

In recent years, radar technology has been extensively utilized in contactless human behavior monitoring systems. The unique capabilities of ultra-wideband (UWB) radars compared to conventional radar technologies, due to time-of-flight measurements, present new untapped opportunities for in-depth monitoring of human movement during overground locomotion. This study aims to investigate the deployability of UWB radars in accurately capturing the gait patterns of healthy individuals with no known walking impairments. A novel algorithm was developed that can extract ten clinical spatiotemporal gait features using the Doppler information captured from three monostatic UWB radar sensors during a 6-meter walking task. Key gait events are detected from lower-extremity movements based on the joint range-Doppler-time representation of recorded radar data. The estimated gait parameters were validated against a gold-standard optical motion tracking system using 12 healthy volunteers. On average, nine gait parameters can be consistently estimated with 90-98% accuracy, while capturing 94.5% of participants' gait variability and 90.8% of inter-limb symmetry. Correlation and Bland-Altman analysis revealed a strong correlation between radar-based parameters and the ground-truth values, with average discrepancies consistently close to 0. Results prove that radar sensing can provide accurate biomarkers to supplement clinical human gait analysis, with quality similar to gold standard assessment. Radars can potentially allow a transition from expensive and cumbersome lab-based gait analysis tools toward a completely unobtrusive and affordable solution for in-home deployment, enabling continuous long-term monitoring of individuals for research and healthcare applications.

Comprehensive technical analysis of a kickboxing fight in K1 format based on observation

Introduction: Observation and specialized analysis of confrontations in combat sports are fundamental for introducing corrections in training programs and for modifying the individual technical-tactical profiles of athletes in these types of activities. These actions comprehensively assess the progress of sports activities, ultimately inspiring and guiding the direction of training in sports clubs. The aim of this study was to analyze and assess the level of the offensive structure of Kickboxing sport fights in the K1 format, in terms of global simulated sparring, in selected thematic sets. Materials and Methods: The research material consisted of a multimedia recording of 10 simulated K1 sparring sessions, in which 20 professional athletes of this discipline participated (age: 24.5 ± 4.6 years; body height: 179.1 ± 4.6 cm; body weight: 81.7 ± 9.9 kg; BMI: 25.5 ± 3.7; training experience: 6.9 ± 1.3 years). To assess the offensive structure of the fight, a retrospective analysis of the recorded empirical material was conducted in terms of the quantity of attacks made, and then specialized technical-tactical preparation (PTT) indicators were calculated, in the global context of sparring, for thematic sets (total; punches vs kicks; right vs left limb attacks; type of techniques; direction of attack). Results: The analysis revealed a significantly higher technical-tactical efficiency regarding hand strikes, left hand, and direction of strikes to the opponent's head in terms of activity (p < 0.001), effectiveness (p < 0.001), and efficiency (p = 0.008–0.408) of attack. In isolated analysis of kicking techniques, a significant advantage in efficiency was registered for selected attacks directed at the lower parts of the opponent's body, i.e., torso, legs (p =< 0.001–0.043). The most effective and exploited techniques were: left straight (Aa x̃=36.8; Sa x̃=23.9), and for kicks, right low kick (Aa x̃=14.9; Sa x̃=5.6). The highest attack efficiency was noted for the right middle kick (Ea x̃=54.18). Several selected comparative sets (inter-limb symmetry, type of attack, direction of attack) for technical-tactical efficiency, were characterized by significant statistical differentiation (p=<0.001–0.048). Conclusions: Kickboxing is an asymmetrical combat sport, which necessitates the application of targeted training on individual body segments of the athlete, and compensatory actions in the prevention of injuries. The study results allow for detailed diagnosis and interpretation of the technical-tactical profile along with the key manifestation of offensive competencies in Kickboxing profession in the K1 format, favoring the optimization of the quality of coaching control.

Longitudinal assessment of knee joint proprioception using weight-bearing and non-weight-bearing tests throughout rehabilitation after anterior cruciate ligament reconstruction

ObjectiveEvaluate active knee joint position sense (JPS) throughout rehabilitation after anterior cruciate ligament reconstruction (ACLR). DesignLongitudinal. SettingMotion laboratory. ParticipantsTwenty-two individuals post-ACLR and 22 activity-matched non-injured controls performed weight-bearing and non-weight-bearing knee JPS tests. The ACLR participants performed at three functional timepoints: T1, able to perform single-leg sit-to-stand; T2, able to hop maximally; T3, cleared for return to sports. Controls performed on one occasion. Main outcome measuresConstant, absolute, variable errors (CE, AE, VE) and interlimb symmetry estimates (100% signifying perfect symmetry), for 40° and 65° knee flexion target angles. ResultsFor the weight-bearing 40° condition, CE and AE of the ACLR knee significantly increased from T1 to T2 (P = 0.010) and T1 to T3 (P = 0.002). Consequently, interlimb asymmetry for AE significantly increased from T1 (AEsym% = 101.2% ± 55.4%) to T3 (AEsym% = 139.7% ± 54.8%). Compared to controls, AE for the ACLR knee was significantly smaller at T1 (P = 0.016). No other significant differences were observed. ConclusionsSmaller JPS errors at early rehabilitation while weight-bearing may have been due to heightened quadriceps activation and increased γ motor neuron sensitivity, compensating for deficient ACL mechanoreceptors. In contrast, non-weight-bearing testing did not reveal changes over time. Clinicians are advised to consider these distinctions when assessing proprioception at different rehabilitation stages.

Cyclogram-based evaluation of inter-limb gait symmetry in Prader-Willi Syndrome

BackgroundPrader-Willi syndrome (PWS) is characterized by a complex clinical condition, whose typical features lead to impaired motor and functional skills. To date, limited data is available as regards symmetry of gait in PWS. Research questionThe aim of this study was to characterize lower-limb asymmetry during gait in a group of Prader-Willi Syndrome (PWS) individuals by using the synchronized cyclograms and to compare it with those of two different control groups, a normal-weight group and an obese group. MethodsA total of 18 PWS, 30 normal weight (NW) and 28 obese individuals (OG) matched for age, sex and height were assessed via 3D gait analysis. Gait spatio-temporal parameters were computed together with angle-angle diagrams, characterized in terms of their geometric features (i.e. area, orientation, and trend symmetry index). ResultsIndividuals with PWS exhibit reduced speed, stride length and cadence and increased duration of both stance and double support phase than the other groups. OG was characterized by the same pattern when compared to NW. With respect to inter-limb symmetry, individuals with PWS exhibited significantly larger cyclogram areas at hip joint with respect to the other two groups (203.32 degrees2 vs. 130.73 degrees2 vs. 111.59 degrees2) and significantly higher orientation angle (4.17° vs. 2.11° vs. 1.22°) and Trend Symmetry (3.72 vs. 2.02 vs. 1.21) with respect to the other two groups at knee joint; no differences were found at ankle joint. Both individuals with PWS and those of OG exhibited reduced ROM at knee and ankle joints with respect with normal weight, but no statistically significant differences were observed between PWS and OG. SignificanceThe obtained results may provide novel and useful insights to understand better the impairments in motor control associated with this pathological state, supporting clinics in the identification of the best rehabilitation program for this rare pathological state, aimed to improve stability and motor control.

Comparing the Effects of an Off-Ice Sprint-Change of Direction Task on Trunk Kinematics and Gait Laterality in Collegiate Ice Hockey Players

Laterality preferences are intrinsic in most physical activities, and ice hockey is one domain wherein these preferences might influence performance. Biomechanical laterality between dominant and nondominant (or preferred and nonpreferred) limbs is believed to be an advantageous attribute that is linked with skilled performance. Yet little is known about the implications of motor asymmetries for skilled performers in dynamic, time-constrained, team-based activities in an off-ice environment. This can be extended to when player position is considered, notably for those playing in a defensive or an offensive position. In this study, fourteen semi-professional collegiate male ice hockey players (age: 21.87 ± 2.98 years; BMI: 25.26 ± 3.21 kg/m) performed a randomized repeated 15 m sprint-change of direction task. Assessments of lower limb laterality were carried out as participants commenced the 15 m sprint change of direction task in both a right and left foot rear setback position. Biomechanical laterality between right and left rear foot setback positions was inferred by an ActiGraph GTx3 triaxial accelerometer that was located on the participants’ spinous process, representing the trunk centre of mass (CoM). Overall, ANOVA results indicated significant differences across all sprint split times between the right and left foot rear setback positions, with times significantly quicker when players commenced in a right rear foot setback position (p < 0.001). ANOVA revealed significant differences in trunk CoM acceleration between in a right and left rear setback position, specifically during the initial 0–10 m sprint split, with offensive players observed to have lesser trunk anteroposterior and vertical CoM acceleration (p = 0.05) and during the final 5 m sprint split (p = 0.002, d = 0.7), despite overall smaller effect sizes seen in the left foot rear setback position. It appears that starting with the foot in a right rear setback position results in quicker 15 m performance times and concurrent lower magnitudes of trunk CoM acceleration. Although we demonstrated that offensive players were quicker and displayed less trunk CoM acceleration, we recommend that future studies use a greater number of participants for inter-limb symmetry in these movement tests.

Exoskeleton-assisted training to enhance lower limb motor recovery in subacute stroke: does timing matter? A pilot randomized trial

BackgroundLower limb motor recovery, including abnormal muscle synergies, occurs mainly within the first 5–8 weeks after a stroke. This suggests the importance of delivering impairment-focused therapies, such as therapeutic robots that promote symmetric gait, during this time-sensitive period, following the principle of “the earlier, the better.”ObjectiveFirst, to compare early robotic training (ERT) with usual care (UC) against UC alone on restoring intralimb muscle synergies and interlimb symmetry during functional tasks; Second, to investigate whether ERT is superior to delayed robotic training (DRT) starting after the proposed time-sensitive period.MethodsThis observer-blinded, randomized pilot trial with crossover design involved 19 nonambulatory adults included within 14 days poststroke. Those allocated to ERT (N = 10) received immediately 4 weeks of training (16 sessions, 4× /week) with the Ekso GT® above UC and were compared with the DRT group (N = 9) who received UC alone at this point. Thereafter a 3-week UC period followed to investigate sustainability of ERT and the interventional roles were exchanged; at about week 8 poststroke DRT subjects started the same experimental robotic protocol and ERT subjects continued UC as controls. Outcomes included changes in Fugl-Meyer lower extremity scores (FM-LE) reflecting muscle synergies, weight-bearing asymmetry (WBA), and dynamic control asymmetry (DCA) during quiet standing. Functional ambulation category (FAC) was used to classify walking independence (cut-off ≥4).ResultsA trend toward earlier reacquisition of walking independence favoring ERT with UC over UC was not accompanied by differences in FM-LE, WBA, or DCA (first objective). Thereafter, DRT with UC did not yield any significant changes relative to UC, such that no between-group differences were found favoring restorative effects of ERT over DRT (second objective).ConclusionThis pilot trial shows the feasibility of investigating a wearable exoskeleton as an adjunct therapy in subacute stroke. Nevertheless, our preliminary findings suggest that motor recovery of lower limb muscle synergies was not enhanced by 4 weeks of robotic training to reduce compensations with the less-affected side, irrespective of the timing of application.Trial registrationClinicalTrials.gov, identifier: NCT03727919.

Evaluation of muscular and functional inter-limb asymmetries during mid-season in young male soccer athletes

BackgroundTo identify inter-limb asymmetries through the knee's muscular and lower limb functional performance in young male soccer athletes. MethodsTwenty male soccer athletes aged 17 to 19 from an under-20 team performed isokinetic tests at 60°/s., 120°/s., 180°/s., and 240°/s. To assess the knee extensors and flexors muscles and functional tests (hop tests and Y-balance test). ResultsThere were no significant differences between the dominant limb (DL) and non-dominant limb (NDL) in the knee extensors and flexors peak torque and hamstrings (H)/quadriceps(Q) conventional ratio. Moreover, no angular velocities observed inter-limb asymmetries seen by values higher than 10% in the isokinetic parameters. However, the H/Q conventional ratio shows borderline values in low angular velocities (60°/s. and 120°/s.). No significant changes were observed in the functional test performance between the DL and NDL. Furthermore, we did not see inter-limb asymmetries in both hop and Y-balance tests. On the contrary, the anterior distance reached was lower than found in the literature, and the composite score of the Y-balance test demonstrated values below the normative (>94%). ConclusionThe data demonstrated that soccer athletes have muscular and functional inter-limb symmetry. However, they tend to have knee muscle imbalance in low velocities and dynamic balance deficits that might increase the risk of musculoskeletal injury.

Synchronized Cyclograms to Assess Inter-Limb Symmetry during Gait in Women with Anorexia and Bulimia: A Retrospective Study

Anorexia nervosa (AN) and bulimia nervosa (BN) are eating diseases characterized by extreme eating behaviours impacting both mental and physical health. Aberrant musculoskeletal adaptations due to malnutrition affect motor abilities such as postural control and gait. To date, limited data is available with regards to gait symmetry in AN and BN. The aim of this study was to characterize inter-limb asymmetry during gait in two cohorts affected by AN and BN, respectively, using the synchronized cyclograms and to compare it with a healthy weight group. A total of 14 AN, 17 BN, and 11 healthy-weight females were assessed via 3D gait analysis. Gait spatio-temporal parameters were computed together with angle–angle diagrams, which were characterized in terms of their geometric features. Individuals with AN and BN were characterized by reduced speed and cadence and an abnormal increase in the duration of the double support phase with respect to the healthy controls. With respect to inter-limb symmetry, asymmetries were detected in both groups, with individuals with BN exhibiting significantly larger cyclogram areas at the hip joint with respect to the other groups (323.43 degrees2 vs. 253.74 degrees2 vs. 136.37 degrees2) and significantly higher orientation angle and Trend Symmetry at both knee and ankle joint. The cyclogram analysis suggests the presence of an altered gait symmetry in individuals with BN. In the AN group, it is possible to observe a similar trend; however, this is not statistically significant. Overall, the findings of this study may provide a novel perspective on the motor control dysfunction linked to eating disorders and aid clinicians in selecting a suitable rehabilitation scheme targeted at enhancing motor stability and control.

Relationship between Body Composition Asymmetry and Specific Performance in Taekwondo Athletes: A Cross-Sectional Study

Currently, there is interest in investigating how interlimb asymmetries (IA) of body composition impact sport-specific performance outcomes. This study aimed to examine the relationship between body composition inter-limb asymmetry and specific performance outcomes in taekwondo athletes. Seventeen national and international athletes (males, n = 8, mean age = 23.3 ± 3.1 years, mean stature = 177.2 ± 8.5 cm, mean body mass = 80.0 ± 7.3 kg; females, n = 9, mean age = 25.0 ± 4.0 years, mean stature = 161.1 ± 4.4 cm, mean body mass = 59.8 ± 5.7 kg) participated in the study. During a non-consecutive 2-day period, body composition (BC) and IA were assessed using dual X-ray absorptiometry, and the magnitude (%) of IA was calculated. Specific-performance included taekwondo specific agility test (TSAT) and Frequency Speed of Kick Test Multiple (FSKTMULT). The relationship between BC asymmetry and performance outcomes was analyzed using a partial correlation approach (controlling for gender, age, and training time). The influence of the significant results was examined using forward stepwise linear regression models. The main results showed no significant differences between the lower limbs (p < 0.05). The IA ranged from 1.37% to 2.96%. Moderate to large negative correlations (r = −0.56 to −0.76, p < 0.05) were documented between IA of body mass, free fat mass (FFM), and lean soft tissue mass (LSTM) with most FSKTMULT outcomes. Bone mineral density (BMD) was correlated with set 5 (rho = −0.49, p = 0.04). The FFM and LSTM asymmetries influenced the KDI reduction by 21%. Meanwhile, IA BMD negatively influenced set 5 performance by 48%. The findings of our study indicate that asymmetries independent of the magnitude of muscle and bone mass-related outcomes may have detrimental effects on high-intensity performance in taekwondo athletes. This underscores the importance of implementing comprehensive training programs and paying attention to achieving body composition inter-limb symmetry to improve overall performance levels in this sport.

Recovery of Quiet Standing Balance and Lower Limb Motor Impairment Early Poststroke: How Are They Related?

Background Recovery of quiet standing balance early poststroke has been poorly investigated using repeated measurements. Objective To investigate (1) the time course of steady-state balance in terms of postural stability and inter-limb symmetry, and (2) longitudinal associations with lower limb motor recovery in the first 3 months poststroke. Methods Forty-eight hemiparetic subjects (age: 58.9 ± 16.1 years) were evaluated at weeks 3, 5, 8, and 12 poststroke. Motor impairments concerned the Fugl-Meyer assessment (FM-LE) and Motricity Index total score (MI-LE) or ankle item separately (MI-ankle). Postural stability during quiet 2-legged stance was calculated as the net center-of-pressure area (COPArea) and direction-dependent velocities (COPVel-ML and COPVel-AP). Dynamic control asymmetry (DCA) and weight-bearing asymmetry (WBA) estimated inter-limb symmetries in balance control and loading. Linear mixed models determined (1) time-dependent change and (2) the between- and within-subject associations between motor impairments and postural stability or inter-limb symmetry. Results Time-dependent improvements were significant for FM-LE, MI-LE, MI-ankle, COPArea, COPVel-ML, and COPVel-AP, and tended to plateau by week 8. DCA and WBA did not exhibit significant change. Between-subject analyses yielded significant regression coefficients for FM-LE, MI-LE, and MI-ankle scores with COPArea, COPVel-ML, and COPVel-AP up until week 8, and with WBA until week 12. Within-subject regression coefficients of motor recovery with change in COPArea, COPVel-ML, COPVel-AP, DCA, or WBA were generally non-significant. Conclusions Postural stability improved significantly in the first 8 weeks poststroke, independent of lower limb motor recovery at the most affected side within subjects. Our findings suggest that subjects preferred to compensate with their less affected side, making metrics reflecting inter-limb asymmetries in balance invariant for change early poststroke. Clinical Trial Registration: Clinicaltrials.gov. unique identifier NCT03728036.

Investigating the impact of inter-limb asymmetry in hamstring strength on jump, sprint, and strength performance in young athletes: comparing the role of gross force.

The main purpose of this cross-sectional study was to examine the impact of the inter-limb asymmetry of hamstring strength on jump, sprint and strength performance and to compare the effects of inter-limb asymmetry of hamstring strength with gross force (GF) of the hamstring on these physical qualities in youth volleyball athletes. Eighty-one youth volleyball players (age: 16.6 ± 1.9years; training experience: 3.0 ± 0.9years; height: 191.4 ± 7.1cm; body mass: 78.5 ± 12.9kg; lean body mass: 63.5 ± 10.5kg; body fat rate: 18.6% ± 6.1%) performed a mid-season battery of tests consisting of morphological test, depth jump (DJ), counter movement jump (CMJ), squat jump (SJ), 10m sprint, isometric mid-thigh pull (IMTP) and hamstring strength test. All tests reported good to excellent reliability (ICC range = 0.815-0.996) and acceptable variability (CV range = 3.26-7.84%). Results show a significant negative relationship between inter-limb asymmetry of hamstring strength and all physical qualities (r = -0.271 to -0.445; p < 0.05), and a significant positive relationship between GF of hamstring and all physical qualities (r = 0.303 to 0.664; p < 0.05). Additionally, GF of hamstring was more relevant to IMTP-PF (peak force) (r = 0.664) and inter-limb asymmetry of hamstring strength was more relevant to 10m sprint (r = -0.445). The findings from this study indicate that, for youth athletes, the GF of the hamstring is crucial for overall lower limb strength performance, and the importance of inter-limb symmetry of hamstring strength increases with the complexity of the task.

Novel Use of an Accelerometer to Assess Load Asymmetry Over Time After Hip Resurfacing Arthroplasty

BackgroundThere is limited knowledge regarding usage of wearable technology to guide return to sport after hip resurfacing arthroplasty (HRA). This study evaluated the use of accelerometers to identify when symmetry is restored between operative and nonoperative limbs. MethodsA total of 26 primary HRA patients performed 5 validated physical tests before, 3 and 6 months after HRA: broad jump, double-leg vertical jump (DLVJ), hop test, lateral single-leg jump (LSLJ), and vertical single-leg jump. Impact load and average intensity data (g-force units) were collected using accelerometers. Strength data (pounds [lbs.]) for internal and external rotation were collected with a dynamometer. Univariate and correlation analyses analyzed interlimb asymmetries. ResultsAt preoperation, there were significant impact load asymmetries for DLVJ (P = .008), hop test (P = .021), and LSLJ (P = .003) and intensity asymmetry for DLVJ (P = .010) and LSLJ (P = .003). At 3 months, there was impact load asymmetry for DLVJ (P = .005) and LSLJ (P = .005) and intensity asymmetry for broad jump (P = .020), hop test (P = .042), and LSLJ (P = .005). There were significant strength asymmetries at preoperation and 3 months postoperation for internal (P = .013) and external rotation (P = .037). All significant asymmetries indicated the nonoperative leg had greater output. No significant asymmetries were found for any exercises at 6 months postoperation. An increase in Harris Hip Score was significantly associated with a decrease in impact asymmetry (rs = −0.269, P = .006). ConclusionImpact loads and strength reach interlimb symmetry at 6 months post-HRA. Wearable accelerometers provide useful metrics to distinguish limb asymmetries for recovery monitoring.

Muscle Asymmetries in the Lower Limbs of Male Soccer Players: Preliminary Findings on the Association between Countermovement Jump and Tensiomyography.

Strength and power asymmetries have been observed in different sports, including soccer. Such asymmetries, as well as the bilateral deficit (BLD), can be assessed during different tasks, static or dynamic, and with different methods and devices, in order to detect the possible different aspects, as well as the association with physical performance and injuries. The aim of this study was to investigate the association between muscle asymmetries and BLD during a countermovement jump (CMJ), and tensiomyography (TMG) parameters and asymmetries, in the lower limbs of male soccer players. A total of 23 male soccer players (18 ± 4 years) were recruited. Bilateral and unilateral CMJs were performed, and peak power (W) and height (cm) were obtained. TMG was performed on different muscles of the lower limbs, and lateral and functional symmetries were obtained. Playing position and history of injuries were collected. CMJ inter-limb symmetry was found to significantly correlate with biceps femoris (r = 0.574, p = 0.004) and soleus (r = 0.437, p = 0.037) lateral symmetry. Players in central roles presented significantly worse functional symmetry scores of the knee than defense players (-17.5%, 95% CI -31.2--3.9; p = 0.10). Participants reporting a history of injury at the ankle were characterized by significantly lower functional symmetry in both the dominant (43%, 39.5-48.0 vs. 74.5%, 46.5-89.3, p = 0.019) and non-dominant (45%, 42.5-46.0 vs. 81.0%, 45.8-90.3, p = 0.024) ankle. Findings from this preliminary study suggest an association between lower-limb muscle asymmetries during a dynamic task, such as jumping, and muscle contractile properties evaluated with TMG; moreover, functional asymmetries may be present after ankle injuries. Future studies in larger samples should evaluate the presence of such asymmetries as predictors or characteristics of different muscular and joint injuries.

A unilateral robotic knee exoskeleton to assess the role of natural gait assistance in hemiparetic patients

BackgroundHemiparetic gait is characterized by strong asymmetries that can severely affect the quality of life of stroke survivors. This type of asymmetry is due to motor deficits in the paretic leg and the resulting compensations in the nonparetic limb. In this study, we aimed to evaluate the effect of actively promoting gait symmetry in hemiparetic patients by assessing the behavior of both paretic and nonparetic lower limbs. This paper introduces the design and validation of the REFLEX prototype, a unilateral active knee–ankle–foot orthosis designed and developed to naturally assist the paretic limbs of hemiparetic patients during gait.MethodsREFLEX uses an adaptive frequency oscillator to estimate the continuous gait phase of the nonparetic limb. Based on this estimation, the device synchronically assists the paretic leg following two different control strategies: (1) replicating the movement of the nonparetic leg or (2) inducing a healthy gait pattern for the paretic leg. Technical validation of the system was implemented on three healthy subjects, while the effect of the generated assistance was assessed in three stroke patients. The effects of this assistance were evaluated in terms of interlimb symmetry with respect to spatiotemporal gait parameters such as step length or time, as well as the similarity between the joint’s motion in both legs.ResultsPreliminary results proved the feasibility of the REFLEX prototype to assist gait by reinforcing symmetry. They also pointed out that the assistance of the paretic leg resulted in a decrease in the compensatory strategies developed by the nonparetic limb to achieve a functional gait. Notably, better results were attained when the assistance was provided according to a standard healthy pattern, which initially might suppose a lower symmetry but enabled a healthier evolution of the motion of the nonparetic limb.ConclusionsThis work presents the preliminary validation of the REFLEX prototype, a unilateral knee exoskeleton for gait assistance in hemiparetic patients. The experimental results indicate that assisting the paretic leg of a hemiparetic patient based on the movement of their nonparetic leg is a valuable strategy for reducing the compensatory mechanisms developed by the nonparetic limb.

Synchronized Cyclograms to Assess Inter-Limb Symmetry during Gait in Post-Stroke Patients

The aim of this study was to assess the inter-limb symmetry during gait in post-stroke patients using the synchronized cyclograms technique. In total, 41 individuals with stroke (21 left and 20 right hemiplegic patients; age: 57.9 ± 12.8 years; time stroke event 4.6 ± 1.8 years) and 48 age-, sex-, and height-matched individuals (control group: CG; age: 54.4 ± 12.5 years) were assessed via 3D gait analysis. Raw kinematic data were processed to compute spatio-temporal parameters (speed, stride length, cadence, stance, swing, and double support phases duration) and angle–angle diagrams (synchronized cyclograms), which were characterized in terms of area, orientation, and trend symmetry indices. The results reveal that all spatio-temporal parameters are characterized by abnormal values, with reduced speed, stride length, cadence, and swing phase duration and increased stance and double support phases duration. With respect to inter-limb symmetry, higher values were found in post-stroke individuals for all the considered parameters as patients generally exhibited a cyclogram characterized by larger areas, higher orientation, and trend symmetry parameters with respect to CG. The described alterations of gait asymmetry are important from a clinical point of view as the achievement of symmetry in gait represents a crucial objective in the rehabilitation of hemiplegic people.

Isokinetic Muscle Strength in Elite Soccer Players 3 and 6 months After Anterior Cruciate Ligament Reconstruction.

Milutinović, A, Jakovljević, V, Dabović, M, Faude, O, Radovanović, D, and Stojanović, E. Isokinetic muscle strength in elite soccer players 3 months and 6 months after anterior cruciate ligament reconstruction. J Strength Cond Res 37(4): e297-e304, 2023-The aim of this study was to evaluate interlimb symmetry in quadriceps and hamstring peak torque of elite soccer players at 3 months (stage 1) and 6 months (stage 2) after anterior cruciate ligament (ACL) reconstruction. Eight male professional soccer players competing at the highest level across different European countries, who had undergone ACL reconstruction, participated in this study. All patients underwent a supervised physiotherapy program after surgery. Data analyses included the use of separate two-way repeated-measures analyses of variance and effect sizes. Although knee extensor and flexor strength of the non-injured limb was found to be relatively unaltered ( g = -0.10 to 0.00) between stage 1 and stage 2, comparisons across time points revealed moderate improvements in quadriceps peak torque ( p = 0.01, g = 0.52), hamstring peak torque ( p = 0.07, g = 0.51), and hamstring:quadriceps (H/Q) ratio ( p = 0.03, g = -0.68) of the injured leg, as well as small-large improvements in the quadriceps ( p = 0.004, g = 1.24) and hamstring limb symmetry index (LSI) ( p = 0.056, g = 0.41). A time-dependent moderate-large asymmetry observed at stage 1 between the injured and noninjured leg in quadriceps peak torque ( p < 0.001, g = -1.83), hamstring peak torque ( p = 0.157, g = -0.67), and the H:Q ratio ( p = 0.06, g = 1.01), as well as between the hamstring and quadriceps LSI ( p = 0.03, g = -0.74) was eliminated at stage 2 ( g = -0.31 to 0.42). Our findings indicate the importance of supervised and comprehensive therapy, as well as strength screening to assist in recovery aimed at optimizing identified strength deficits following ACL reconstruction.

Inter limb symmetry of selected foot anthropometric measures and its relationship to vertical jumping ability

Aim: The study was intended to examine the symmetry between right and left foot; and to analyse the degree of relationship of selected foot anthropometric measurements on different vertical jumping performance. Methods: The criterion variables right foot length, left foot length, right foot breadth, left foot breadth, arch of right foot, arch of left foot, right foot index, left foot index, and foot symmetry index, vertical jump height, counter movement jump height, and squat jump height chosen for the study were measured using the sliding caliper, protractor, Microgate OptoJump, and Microgate Gyko. Descriptive analysis is performed to compute the percentage of inter limb variation, ‘t’ ratio for the existence of significant difference, and Pearson product moment correlation coefficient to determine association among criterion variables. Results: It is found that foot length, foot breadth, and arch of the foot are asymmetrical between limbs, and furthermore shows very little to no considerable association between foot anthropometry and vertical jumping ability. Conclusion: Thus, we conclude that the individuals with broader foot breadth, greater foot index and corresponding foot symmetry impacts largely than foot length and arch of the foot.

Metabolic cost of transport and stance time asymmetry in individuals with unilateral transtibial amputation using a passive prostheses while walking

BackgroundPeople with unilateral amputation typically walk with greater metabolic cost than able-bodied individuals, while preferring asymmetric walking characteristics. It is unclear if asymmetric walking is energetically optimal and how metabolic cost accounts for asymmetric patterns in people with amputation. The purpose of this study was to determine the effects of stance-time asymmetry on the metabolic cost of transport. MethodsFourteen participants (seven with amputation) completed two laboratory sessions where they walked on a treadmill while receiving real-time visual feedback about stance-time asymmetry. Expired gases were collected to determine the metabolic cost for a range of asymmetries (−15% to +15% in 5% increments, positive percentages represent more time on intact [dominant] limb). FindingsParticipants with amputation walked with greater (P = 0.008) stance-time asymmetry (4.34 ± 1.09%) compared with able-bodied participants (0.94 ± 2.44%). Stance-time asymmetry had a significant effect on metabolic cost (P < 0.001). The asymmetries coinciding with the predicted minimum metabolic cost for people with (3.23 ± 2.90%) and without (1.81 ± 2.18%) amputation were not different from preferred asymmetries (P = 0.365; p = 0.513), respectively. The cost of symmetric walking was 13.6% greater than near preferred walking for people with amputation (5% more time on intact limb). InterpretationMetabolic cost is not the only objective of walking, but like able-bodied individuals, it may influence how people with amputation walk. Rehabilitation typically tries to restore inter-limb symmetry after an injury, yet if the limbs are asymmetric, symmetric gait may not be optimal with current assistive devices.

Inter-limb asymmetry of kinetic and electromyographic during walking in patients with chronic ankle instability

After an initial ankle sprain, a relevant number of participants develop chronic ankle instability (CAI). Compensatory strategies in patients with CAI may change the inter-limb symmetry needed for absorbing movement-related forces. Accordingly, an increased risk of injury can occur. The present study aimed to compare the inter-limb asymmetry of kinetic and electromyography between individuals with CAI and without a history of an ankle sprain (Non-CAI) during walking. In this cross-sectional study, fifty-six athletes (28 CAI; 28 Non-CAI) participated. Participants walked at a comfortable pace over level ground while vertical ground reaction force (vGRF) and muscle activity of the tibialis anterior, peroneus longus, medial gastrocnemius, and gluteus medius were recorded. Inter-limb asymmetry during walking was calculated for each of the variables. Patients with CAI exhibited a greater inter-limb asymmetry of the first peak of vGRF, time to peak vGRF, and loading rate (P < 0.001), as well as presenting a greater inter-limb asymmetry of peroneus longus activity (contact phase) (P = 0.003) and gluteus medius activity (midstance/propulsion phase) (P = 0.010) compared to the Non-CAI group. No other differences in vGRF or muscles activity were observed between the groups. Our findings indicate that patients with CAI walk with greater inter-limb asymmetry in vGRF and muscle activity in different phases of the gait cycle compared to Non-CAI group. Our results could inform future studies on gait training aimed to reduce asymmetry during walking in patients with CAI.

Strides to Achieve a Stable Symmetry Index During Running.

The quality of running mechanics is often characterized by limb pattern symmetry and used to support clinical decisions throughout the rehabilitation of lower-extremity injuries. It is valuable to ensure that gait analyses provide stable measures while not asking an individual to complete an excessive number of running strides. The present study aimed to determine the minimum number of strides required to establish a stable mean symmetry index (SMSI) of discrete-level measures of spatiotemporal parameters, joint kinematics, and joint kinetics. Further, the study aimed to determine if differences occurred between random and consecutive strides for directional and absolute symmetry indices. Descriptive laboratory study. A sequential average was used to determine how many strides were required to achieve a SMSI within a 60-second trial. Multiple 2-factor repeated-measure analysis of variances were used to determine if differences between bins of strides and symmetry calculations were significantly different. A median SMSI was achieved in 15 strides for all biomechanical variables. There were no significant differences (P > .05) found between consecutive and random bins of 15 strides within a 60-second trial. Although there were significant differences between symmetry calculation values for most variables (P < .05), there appeared to be no systematic difference between the numbers of strides required for stable symmetry for either index. As 15 strides were sufficient to achieve a SMSI during running, a continued emphasis should be placed on the number of strides collected when examining interlimb symmetry.