Risk Factors Associated with Musculoskeletal Injuries within the Crew of the Leopard 2 A6 Main Battle Tank Using Inertial Movement Unit Sensors: A Pilot Study.

This study aims to assess the musculoskeletal risk of military personnel on a Leopard 2 A6 main battle tank crew and to identify associated factors for future prevention and mitigation strategies. A sample of 57 Portuguese military personnel, who are or were part of the Leopard 2 A6 main battle tank crew, answered a questionnaire on their perception of task performance, considering muscle demands, comfort, posture, movements, and associated symptoms. A subsample of four soldiers from the Armoured Squadron of the Portuguese Mechanized Brigade were assessed using an inertial measurement unit system and underwent a whole-body kinematic analysis coupled with a Rapid Entire Body Assessment during a simulated two-hour mission. The results indicate that soldiers accurately perceive their roles within the crew and that, overall, there is a high risk of musculoskeletal injuries in all tasks. However, tasks directly related to the crew's primary duties carry consistently high risk when considering the time spent on their tasks. This study highlights the need for targeted preventive measures to reduce the incidence and severity of injuries among the crew of the Leopard 2 A6 main battle tank.

Evaluation of Upper Limb Joint Contribution to Racket Head Speed in Elite Tennis Players Using IMU Sensors: Comparison between the Cross-Court and Inside-Out Attacking Forehand Drive.

This study aimed to quantify and compare the upper limb angular kinematics and its contributions to the racket head speed between the cross-court (CC) and inside-out (IO) attacking tennis forehand of elite tennis players in a competitive environment. A new approach was used to study the forehand drive with mini-inertial sensors of motion capture to record the kinematic data. Six strokes in each direction per participant (72 shots in total) were chosen for analysis. Upper limb kinematics were calculated in the Visual 3D platform (Visual 3D Professional V5.01.21, C-motion, Germantown, MD, USA). The method used to calculate the upper limb's contributions was performed with MATLAB software and used the segment's (upper arm, forearm and hand) angular velocities and their respective displacement vectors obtained through the inertial sensors. Upper limb kinematics demonstrated a higher shoulder rotation in the IO direction with significant differences at the end of the backswing, which could be a key factor in distinguishing the two directions of the shot. Results also demonstrated that the horizontal flexion of the upper arm (around the shoulder joint) was primarily responsible for the racket velocity in the anteroposterior direction (48.1% CC and 45.2% IO), followed by the extension of the forearm (around the elbow joint) (17.3% CC and 20.9% IO) and the internal rotation of the upper arm (around the shoulder joint) (15.6% CC and 14.2% IO). No significant differences were shown in the contributions of upper limbs to the racket head velocity between the two directions of the shot. Tennis coaches and players should develop a specific training programme to perform higher angular velocities in these specific joint rotations.

Validation of quantitative gait analysis systems for Parkinson's disease for use in supervised and unsupervised environments.

BACKGROUND: Gait impairments are among the most common and impactful symptoms of Parkinson's disease (PD). Recent technological advances aim to quantify these impairments using low-cost wearable systems for use in either supervised clinical consultations or long-term unsupervised monitoring of gait in ecological environments. However, very few of these wearable systems have been validated comparatively to a criterion of established validity. OBJECTIVE: We developed two movement analysis solutions (3D full-body kinematics based on inertial sensors, and a smartphone application) in which validity was assessed versus the optoelectronic criterion in a population of PD patients. METHODS: Nineteen subjects with PD (7 female) participated in the study (age: 62 ± 12.27 years; disease duration: 6.39 ± 3.70 years; HY: 2 ± 0.23). Each participant underwent a gait analysis whilst barefoot, at a self-selected speed, for a distance of 3 times 10 m in a straight line, assessed simultaneously with all three systems. RESULTS: Our results show excellent agreement between either solution and the optoelectronic criterion. Both systems differentiate between PD patients and healthy controls, and between PD patients in ON or OFF medication states (normal difference distributions pooled from published research in PD patients in ON and OFF states that included an age-matched healthy control group). Fair to high waveform similarity and mean absolute errors below the mean relative orientation accuracy of the equipment were found when comparing the angular kinematics between the full-body inertial sensor-based system and the optoelectronic criterion. CONCLUSIONS: We conclude that the presented solutions produce accurate results and can capture clinically relevant parameters using commodity wearable sensors or a simple smartphone. This validation will hopefully enable the adoption of these systems for supervised and unsupervised gait analysis in clinical practice and clinical trials.

Intermuscular Coordination in the Power Clean Exercise: Comparison between Olympic Weightlifters and Untrained Individuals-A Preliminary Study.

Muscle coordination in human movement has been assessed through muscle synergy analysis. In sports science, this procedure has been mainly applied to the comparison between highly trained and unexperienced participants. However, the lack of knowledge regarding strength training exercises led us to study the differences in neural strategies to perform the power clean between weightlifters and untrained individuals. Synergies were extracted from electromyograms of 16 muscles of ten unexperienced participants and seven weightlifters. To evaluate differences, we determined the pairwise correlations for the synergy components and electromyographic profiles. While the shape of activation patterns presented strong correlations across participants of each group, the weightings of each muscle were more variable. The three extracted synergies were shifted in time with the unexperienced group anticipating synergy #1 (-2.46 ± 18.7%; p < 0.001) and #2 (-4.60 ± 5.71%; p < 0.001) and delaying synergy #3 (1.86 ± 17.39%; p = 0.01). Moreover, muscle vectors presented more inter-group variability, changing the composition of synergy #1 and #3. These results may indicate an adaptation in intermuscular coordination with training, and athletes in an initial phase of training should attempt to delay the hip extension (synergy #1), as well as the upper-limb flexion (synergy #2).

Influence of full range of motion vs. equalized partial range of motion training on muscle architecture and mechanical properties.

PURPOSE: The purpose of this study was to determine the effect of a 15-week partial range of motion (ROM) resistance training program on the vastus lateralis (VL) architecture and mechanical properties, when the time under tension (TUT) was equalized. METHODS: Nineteen untrained male subjects were randomly assigned to a control (Control; n = 8) or training (TG; n = 11) group. In the TG, the dominant and nondominant legs were randomly selected to be trained with a full ROM (FULL) or a partial ROM (PART) in an isokinetic dynamometer. Training volume was equalized based on the TUT by manipulating sets and repetitions. The VL muscle architecture was assessed by B-mode ultrasonography at rest and during maximal isometric knee extension contractions (MVCs) at ten knee angles. The VL fascicle force and specific tension were calculated from the MVCs with superimposed stimuli, accounting for the moment arm length, muscle architecture, and antagonist coactivation. RESULTS: The FULL training induced changes in fascicle length (FL) (4.9 ± 2.0%, P < 0.001) and specific tension (25.8 ± 18.7%, P < 0.001). There was a moderate effect of PART training on the physiological cross-sectional area (PCSA) (7.8 ± 4.0%, P < 0.001, dav = 0.6) and torque-angle adaptations (average increase 17.7 ± 3.9%, P < 0.05). CONCLUSIONS: These results provide evidence that crucial architectural and mechanical muscle adaptations are dependent on the ROM used in strength training. It seems that muscle FL and specific tension can be increased by pure concentric training if greater ROM is used. Conversely, restricting the ROM to shorter muscle lengths promotes a greater PCSA and angle-specific strength adaptations.

Community-Based Exercise Intervention for Gait and Functional Fitness Improvement in an Older Population: Study Protocol.

Functional fitness (FF) and gait ability in older populations have been associated with increased survival rates, fall prevention, and quality of life. One possible intervention for the improvement of FF is well-structured exercise programs. However, there are inconsistent findings regarding the effects of exercise interventions in the maintenance of gait parameters. The aim of this protocol is to develop a community-based exercise intervention targeting an older population. The intervention aim is the improvement of gait parameters and FF. A control trial with follow-up will be performed. The primary outcome variables will be plantar pressure gait parameters. The secondary outcome variables will be aerobic endurance, lower limb strength, agility, and balance. These variables will be recorded at baseline and after 12, 24, and 36 weeks, in the intervention and control groups. If effective, this protocol can be used by exercise professionals in improving community exercise programs.

A Global Gait Asymmetry Index.

High levels of gait asymmetry are associated with many pathologies. Our long-term goal is to improve gait symmetry through real-time biofeedback of a symmetry index. Symmetry is often reported as a single metric or a collective signature of multiple discrete measures. While this is useful for assessment, incorporating multiple feedback metrics presents too much information for most subjects to use as visual feedback for gait retraining. The aim of this article was to develop a global gait asymmetry (GGA) score that could be used as a biofeedback metric for gait retraining and to test the effectiveness of the GGA for classifying artificially-induced asymmetry. Eighteen participants (11 males; age 26.9 y [SD = 7.7]; height 1.8 m [SD = 0.1]; body mass 72.7 kg [SD = 8.9]) walked on a treadmill in 3 symmetry conditions, induced by wearing custom-made sandals: a symmetric condition (identical sandals) and 2 asymmetric conditions (different sandals). The GGA score was calculated, based on several joint angles, and compared between conditions. Significant differences were found among all conditions (P < .001), meaning that the GGA score is sensitive to different levels of asymmetry, and may be useful for rehabilitation and assessment.

Sensitivity of joint kinematics and kinetics to different pose estimation algorithms and joint constraints in the elderly.

The purpose of this research was to study the sensitivity of lower limb joint kinematics and kinetics, calculated during different functional tasks (walking, stair descent and stair ascent) in a sample of older adults, to different pose estimation algorithms and models' joint constraints. Three models were developed and optimized differently: in one model, each segment had 6 degrees of freedom (segment optimization, SO), while in the other two, global optimization (GO) was used, with different joint constraints: (1) GO, allowing all joint rotations; (2) GOR, allowing three rotations at the hip, one at the knee (flexion/extension) and two at the ankle (dorsi/plantar flexion and eversion/inversion). The results showed that joint angles are more sensitive to the model's constraints than joint moments and, the more restrictive the model, the higher the differences between models, especially for the frontal and transverse planes (max. RMS difference during gait: 11.7 degrees (64%) vs 0.12 N·m/kg (35.4%). In addition, except for knee abduction/adduction angle, differences between SO and GO models were relatively low. Since GO avoids the nonanatomical dislocations sometimes observed in SO, choosing this model seems to be reasonable for future studies with a similar sample and study design.

Changes in passive and active hamstrings shear modulus are not related after a warmup protocol.

This study aimed to determine whether changes in hamstrings passive and active shear modulus after a warmup protocol are correlated. Twenty males without a history of hamstring strain injury participated. Muscle shear modulus was assessed using ultrasound-based shear wave elastography at rest and during isometric contractions at 20% of maximal voluntary isometric effort before and immediately after a warmup protocol. Changes in passive shear modulus did not seem to be associated with changes in active shear modulus. The results of this study suggest that changes in passive and active hamstring shear modulus are not associated after a standardized warmup intervention.

Markerless three-dimensional gait analysis in healthy older adults: test-retest reliability and measurement error.

In older adults, gait analysis may detect changes that signal early disease states, yet challenges in biomechanical screening limit widespread use in clinical or community settings. Recently, a markerless method from multi-camera video data has become accessible, making screenings less challenging. This study evaluated the test-retest reliability and measurement error of markerless gait kinematics and kinetics in healthy older adults. Twenty-nine healthy older adults performed gait analysis on two occasions, at preferred walking speed, using their everyday clothes. Lower limb angles and moments were averaged from 8 gait cycles. Integrated pointwise indices [Intraclass Correlation Coefficient (ICCA,K) and Standard Error of Measurement (SEM)] were calculated for curve data, as well as ICCA,K, and SEM [95 % confidence intervals] for selected peaks. Generally, kinematic ICCs were good (>0.75) and reasonably stable throughout the gait cycle, except for the hip kinematics during the swing phase in the sagittal plane and pelvis tilt and rotation. The integrated and peaks SEM were <2.4°. The reliability of kinetics was similar (ICC>0.75), except for the transverse hip moment and abduction peak, fluctuating more during the swing than through the stance phase. SEM were < 0.07Nm/Kg. In conclusion, these results showed good overall test-retest reliability for markerless gait kinematics and kinetics for the hip, knee, and ankle joints, moderate for the pelvis angles, and error levels of ≤5°, and SEM%≤5% for the sagittal plane. This supports this method's use in assessing gait in healthy older adults, including kinetics, for which reliability data from markerless systems is difficult to find reported.

Hamstrings passive and active shear modulus: Implications of conventional static stretching and warmup.

PURPOSE: This study compares the acute effects of a static stretching and a warmup protocol on the active and passive shear modulus of the hamstring muscles. METHODS: Muscle shear modulus was assessed at rest and during isometric contractions at 20 % of maximal voluntary isometric contraction (MVIC). RESULTS: After stretching, the passive shear modulus pattern was not altered, while at 20 % MVIC the biceps femoris short head (BFsh) and semimembranosus showed a shear modulus increase and decrease, respectively, which resulted on BFsh-SM pair differences (pre: 3.8 ±â€¯16.8 vs. post: 39.3 ±â€¯25.1 kPa; p < 0.001; d = 1.66) which was accompanied by a decrease of 18.3 % on MVIC. Following the warmup protocol, passive shear modulus remained unchanged, while active shear modulus was decreased for the semitendinosus (pre: 65.3 ±â€¯13.5 vs. post: 60.3 ±â€¯12.3 kPa; p = 0.035; d = 0.4). However, this difference was within the standard error of measurement (10.54 kPa), and did not impact the force production, since it increased only 1.4 % after the warmup. CONCLUSIONS: The results of this study suggest that the passive and active shear modulus responses of the individual hamstring muscles to static stretching are muscle-specific and that passive and active hamstring shear modulus are not changed by a standard warmup intervention.

The PICO project: aquatic exercise for knee osteoarthritis in overweight and obese individuals.

BACKGROUND: Aquatic exercise is recommended by the Osteoarthritis Research Society (OARSI), by the American College of Rheumatology (ACR) and by the European League Against Rheumatism (EULAR) as a nonpharmacological method of controlling the knee osteoarthritis (KOA) symptoms. Moreover, given that weight loss results in a reduction of the load that is exerted upon the knee during daily activities, obesity is also considered to be a modifiable risk factor for the development and or exacerbation of KOA. The implementation of an exercise based weight loss program may, however, itself be limited by the symptoms of KOA. The aquatic program against osteoarthritis (termed "PICO" in Portuguese) prioritizes the control of symptoms and the recovery of functionality, with an attendant increase in the patient's physical activity level and, consequently, metabolic rate. Our laboratory is assessing the effectiveness of 3 months of PICO on the symptoms of KOA, on physical function, on quality of life and on gait. In addition, PICO shall examine the effects of said exercise intervention on inflammatory biomarkers, psychological health, life style and body composition. METHODS/DESIGN: The trial is a prospective, single-blinded, randomized controlled trial, and involves 50 overweight and obese adults (BMI = 28-43.5 kg/m²; age 40-65 yrs) with radiographic KOA. The participants are randomly allocated into either an educational attention (control) group or an aquatic (exercise program) group. This paper describes the experimental protocol that is used in the PICO project. DISCUSSION: The PICO program shall provide insight into the effectiveness of an aquatic exercise program in the control of KOA symptoms and in the improvement of the quality of life. As such, they are likely to prove a useful reference to health professionals who intend to implement any kind of therapeutic intervention based around aquatic exercise. TRIAL REGISTRATION: NCT01832545.

A genetic algorithm approach to design job rotation schedules ensuring homogeneity and diversity of exposure in the automotive industry.

Job rotation is a work organization strategy with increasing popularity, given its benefits for workers and companies, especially those working with manufacturing. This study proposes a formulation to help the team leader in an assembly line of the automotive industry to achieve job rotation schedules based on three major criteria: improve diversity, ensure homogeneity, and thus reduce exposure level. The formulation relied on a genetic algorithm, that took into consideration the biomechanical risk factors (EAWS), workers' qualifications, and the organizational aspects of the assembly line. Moreover, the job rotation plan formulated by the genetic algorithm formulation was compared with the solution provided by the team leader in a real life-environment. The formulation proved to be a reliable solution to design job rotation plans for increasing diversity, decreasing exposure, and balancing homogeneity within workers, achieving better results in all of the outcomes when compared with the job rotation schedules created by the team leader. Additionally, this solution was less time-consuming for the team leader than a manual implementation. This study provides a much-needed solution to the job rotation issue in the manufacturing industry, with the genetic algorithm taking less time and showing better results than the job rotations created by the team leaders.

Predictive Factors of Short-Term Related Musculoskeletal Pain in the Automotive Industry.

To determine the short-term associations between biomechanical risk factors and musculoskeletal symptoms in the upper limbs and low back in an automotive company, a longitudinal study with a follow-up of 4 days was conducted in a sample of 228 workers of the assembly and paint areas. Data were analyzed using generalized estimating equations, calculating the crude and adjusted model for age, sex, seniority, and intensity of pain at baseline. The interactions found were the same for both models. Workers were divided in low-risk and high-risk group for posture, force, exposure, percentage of cycle time with the arm at/above shoulder level, and with the trunk flexed or/and strongly flexed. The predictive factors showed by time × group effect were found between pain intensity on the left shoulder for posture (ß = 0.221, p < 0.001), percentage of time with the trunk flexed (ß = 0.136, p = 0.030) and overall exposure (ß = 0.140, p = 0.013). A time × group interactions were observed, namely between neck pain and posture (ß = 0.218, p = 0.005) and right wrist and force (ß = 0.107, p = 0.044). Workers in the high-risk group were more prone to report unfavorable effects on their self-reported musculoskeletal pain, across a workweek when exposed to specific risk factor, being posture important to neck, right wrist and left shoulder pain.

Effects of collagen membranes enriched with in vitro-differentiated N1E-115 cells on rat sciatic nerve regeneration after end-to-end repair.

Peripheral nerves possess the capacity of self-regeneration after traumatic injury but the extent of regeneration is often poor and may benefit from exogenous factors that enhance growth. The use of cellular systems is a rational approach for delivering neurotrophic factors at the nerve lesion site, and in the present study we investigated the effects of enwrapping the site of end-to-end rat sciatic nerve repair with an equine type III collagen membrane enriched or not with N1E-115 pre-differentiated neural cells. After neurotmesis, the sciatic nerve was repaired by end-to-end suture (End-to-End group), end-to-end suture enwrapped with an equine collagen type III membrane (End-to-EndMemb group); and end-to-end suture enwrapped with an equine collagen type III membrane previously covered with neural cells pre-differentiated in vitro from N1E-115 cells (End-to-EndMembCell group). Along the postoperative, motor and sensory functional recovery was evaluated using extensor postural thrust (EPT), withdrawal reflex latency (WRL) and ankle kinematics. After 20 weeks animals were sacrificed and the repaired sciatic nerves were processed for histological and stereological analysis. Results showed that enwrapment of the rapair site with a collagen membrane, with or without neural cell enrichment, did not lead to any significant improvement in most of functional and stereological predictors of nerve regeneration that we have assessed, with the exception of EPT which recovered significantly better after neural cell enriched membrane employment. It can thus be concluded that this particular type of nerve tissue engineering approach has very limited effects on nerve regeneration after sciatic end-to-end nerve reconstruction in the rat.

Muscle contributions to maximal single-leg forward braking and backward acceleration in elite athletes.

Abrupt deceleration is a common practice in several sports, where sudden changes of direction are needed to reach the highest performance level. When inappropriately performed, these actions can impose excessive mechanical loads at the lower limb joints, specifically at the knee and ankle joints, usually associated with increased risk of injury. This work aims to estimate muscle forces and muscle contributions to the acceleration of the center of mass during a rapid maximal single-leg forward braking and backward acceleration task. Fourteen elite male injury-free indoor-sports athletes participated in this work. Scaled generic musculoskeletal models, consisting of 12 segments, 23 degrees of freedom, and 92 muscle-tendon actuators were used in OpenSim software. Due to the nature of the musculoskeletal system, all muscles are considered when joint and segment positions, velocities, and accelerations are calculated, resulting in muscles acting to accelerate joints it does not span. The knowledge of muscle interaction during this multijoint task is important and was achieved through an induced acceleration analysis. The vasti (-9.18 ± 2.09 and -7.63 ± 1.33 N/Kg) were the main contributors to the centre of mass deceleration profile along the anterior/posterior direction, aided by the soleus muscle (9.72 ± 2.35 and 9.62 ± 2.07 N/Kg), which counteracted most of the effects applied by gravity along the vertical direction, during both phases. This study provides a computational approach to quantify the dynamical interactions between muscles and joints during an abrupt anterior/posterior deceleration task, thus giving robust and insightful indicators that can be implemented in injury prevention protocols.

Muscle Synergies Reliability in the Power Clean Exercise.

Muscle synergy extraction has been utilized to investigate muscle coordination in human movement, namely in sports. The reliability of the method has been proposed, although it has not been assessed previously during a complex sportive task. Therefore, the aim of the study was to evaluate intra- and inter-day reliability of a strength training complex task, the power clean, assessing participants' variability in the task across sets and days. Twelve unexperienced participants performed four sets of power cleans in two test days after strength tests, and muscle synergies were extracted from electromyography (EMG) data of 16 muscles. Three muscle synergies accounted for almost 90% of variance accounted for (VAF) across sets and days. Intra-day VAF, muscle synergy vectors, synergy activation coefficients and individual EMG profiles showed high similarity values. Inter-day muscle synergy vectors had moderate similarity, while the variables regarding temporal activation were still strongly related. The present findings revealed that the muscle synergies extracted during the power clean remained stable across sets and days in unexperienced participants. Thus, the mathematical procedure for the extraction of muscle synergies through nonnegative matrix factorization (NMF) may be considered a reliable method to study muscle coordination adaptations from muscle strength programs.

Joint moments' contributions to vertically accelerate the center of mass during stair ambulation in the elderly: An induced acceleration approach.

Falls are a serious problem faced by the elderly. Older adults report mostly to fall while performing locomotor activities, especially the ones requiring stair negotiation. During these tasks, older adults, when compared with young adults, seem to redistribute their lower limb joint moments. This may indicate that older adults use a different strategy to accelerate the body upward during these tasks. The purposes of this study were to quantify the contributions of each lower limb joint moment to vertically accelerate the center of mass during stair ascent and descent, in a sample of community-dwelling older adults, and to verify if those contributions were correlated with age and functional fitness level. A joint moment induced acceleration analysis was performed in 29 older adults while ascending and descending stairs at their preferred speed. Agreeing with previous studies, during both tasks, the ankle plantarflexor and the knee extensor joint moments were the main contributors to support the body. Although having a smaller contribution to vertically accelerate the body, during stair descent, the hip joint moment contribution was related with the balance score. Further, older adults, when compared with the results reported previously for young adults, seem to use more their knee extensor moment than the ankle plantarflexor moment to support the body when the COM downward velocity is increasing. By contributing for a better understanding of stair negotiation in community dwelling older adults, this study may help to support the design of interventions aiming at fall prevention and/or mobility enhancement within this population.

Effect of 6-month community-based exercise interventions on gait and functional fitness of an older population: a quasi-experimental study.

BACKGROUND: Gait ability in older adults has been associated with independent living, increased survival rates, fall prevention, and quality of life. There are inconsistent findings regarding the effects of exercise interventions in the maintenance of gait parameters. OBJECTIVES: The aim of the study was to analyze the effects of a community-based periodized exercise intervention on the improvement of gait parameters and functional fitness in an older adult group compared with a non-periodized program. METHODS: A quasi-experimental study with follow-up was performed in a periodized exercise group (N=15) and in a non-periodized exercise group (N=13). The primary outcomes were plantar pressure gait parameters, and the secondary outcomes were physical activity, aerobic endurance, lower limb strength, agility, and balance. These variables were recorded at baseline and after 6 months of intervention. RESULTS: Both programs were tailored to older adults' functional fitness level and proved to be effective in reducing the age-related decline regarding functional fitness and gait parameters. Gait parameters were sensitive to both the exercise interventions. CONCLUSION: These exercise protocols can be used by exercise professionals in prescribing community exercise programs, as well as by health professionals in promoting active aging.

The effects of a single session of lumbar spinal manipulative therapy in terms of physical performance test symmetry in asymptomatic athletes: a single-blinded, randomised controlled study.

BACKGROUND AND AIM: Musculoskeletal disorders in athletes, including spinal biomechanical dysfunctions, are believed to negatively influence symmetry. Spinal manipulative therapy (SMT) is recognised as a safe and effective treatment for musculoskeletal disorders, but there is little evidence about whether it can be beneficial in symmetry. Therefore, this study aimed to measure the effects of lumbar SMT in symmetry. METHODS: Forty asymptomatic athletes participated in the study. The randomisation procedure was performed according to the following group allocation: group 1 (SMT) and group 2 (SHAM). Each participant completed a physical activity questionnaire, and also underwent clinical and physical evaluation for inclusion according to eligibility criteria. Statistical significance (P<0.05) between groups and types of therapy were calculated by physical performance tests symmetry (static position, squat and counter movement jump (CMJ), pre- and post-SMT and SHAM. There were 14 trials of three symmetry tests for each participant, for a total of 560 trials. RESULTS: Lumbar SMT produced immediate effects in symmetry in the static position; however, the same effects were not found in squat and CMJ on symmetry 1. Therefore, our results showed a significant difference in pre- (mean 16.3%) and post-lumbar SMT (mean 3.7%) in static symmetry. However, symmetry 2 showed no statistical significant differences for any of the tests and intervention groups. No statistically significant effects in symmetry pre- to post-SHAM were found in any of the tests. CONCLUSIONS: Statistically significant differences were found in lumbar SMT, but only for static symmetry. These findings suggest that SMT was effective in producing immediate effects in symmetry in the static position, but none in dynamic tests. Future studies could address our study's limitations. CLINICAL TRIALS REGISTER NUMBER: NCT03361592.