Sport-specific characteristics of trunk muscles in collegiate wrestlers and judokas

This study evaluated the sport-specific characteristics of the cross-sectional areas (CSAs) of trunk muscles and trunk muscle strength in wrestlers and judokas. We also examined whether their trunk muscles and muscle strength depended on athletic performance levels in each sport. The subjects comprised 14 male collegiate wrestlers and 14 judokas. Magnetic resonance imaging was used to assess the trunk muscle CSAs at the L3-4 level parallel to the lumbar disc space. A Biodex System3 was used to measure isokinetic trunk flexor and extensor muscle strength of peak torque, work, average torque, and average power. The absolute and relative CSAs of the trunk muscles in the wrestlers and judokas were significantly different (rectus abdominis: wrestling > judo, P < 0.05; obliques: wrestling < judo, P < 0.05; quadratus lumborum: wrestling < judo, P < 0.01). We confirmed that the absolute and relative trunk extensor and flexor strength of peak torque, work, and average torque were significantly higher in the collegiate wrestlers than in judokas. On athletic performance, the tendency of the CSAs and muscular strength of trunk muscles was not consistent with athletic performance levels in each sport. Our findings indicated that the sport-specific characteristics of the CSAs of the trunk muscles and trunk muscle strength obviously differed between the 2 similar sports. Athletes should practice the sport-specific training of trunk muscles and develop sport specificity in their sports. Particularly, wrestlers have to train in trunk flexion and extension motions, and judokas need to strengthen trunk rotation and lateral flexion motions. This information will be available for athletes as well as strength and technical training coaches in wrestling, judo, and the other sports.     

Effect of balance taping on trunk stabilizer muscles for back extensor muscle endurance: A randomized controlled study

Objective:The purpose of this study was to investigate the difference in back extensor muscle endurance before and after kinesiology tape application to all back stabilizer muscles and to the erector spinae alone.Methods:We assessed 32 adults (16 men and 16 women), randomly divided into two groups. In the erector spinae taping (EST) group, kinesiology tape was applied only to the erector spinae, and in the total muscle taping (TMT) group, kinesiology tape was applied to the erector spinae, latissimus dorsi, lower trapezius, internal oblique abdominis, and external oblique abdominis.Results:Both groups showed significant difference in terms of back extensor muscle endurance after kinesiology tape application (p<0.05). Between-group comparison revealed that the TMT group had more back extensor muscle endurance than the EST group (p<0.05) after kinesiology tape application.Conclusions:These findings indicate that, to improve back extensor muscle endurance, kinesiology tape should be applied to all back stabilizer muscles, rather than to the erector spinae muscles alone.     

Knee Extensor Strength Is Associated with Pressure Pain Thresholds in Adults with Fibromyalgia

Objective

Individuals with fibromyalgia (FM) have lower muscle strength and lower pressure pain thresholds (PPT). The primary aim of this study was to determine the associations between muscle strength and PPT in adults with FM to test the hypothesis that greater measures of muscle strength would be associated with greater values of PPT. Secondary aims included determining the effects of pain severity and the peak uptake of oxygen (Vo₂) on the associations between muscle strength and PPT.

Methods

Knee extensor and flexor strength (N = 69) was measured in the dominant leg using a dynamometer, and PPT was assessed using an electronic algometer. Pain severity was determined using the Multidimensional Pain Inventory, and peak Vo₂ uptake was quantified using an electronically braked cycle ergometer.

Results

Univariable linear regression analysis demonstrated a significant association between PPT (dependent variable) and isometric knee extensor (P<.001), isokinetic (60°/s) knee extensor (P = .002), and isokinetic (60°/s) knee flexor strength (P = .043). In a multiple variable linear regression analysis adjusted for age, sex, pain severity, body mass index and peak Vo₂ uptake, a significant association was found between PPT and isometric knee extensor strength (P = .008). In a similar multiple variable analysis, a significant association was found between PPT and isokinetic knee extensor strength (P = .044).

Conclusion

Greater measures of isometric and isokinetic knee extensor strength were significantly associated with greater values of PPT in both univariable and multiple variable linear regression models.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01253395","term_id":"NCT01253395"}}NCT01253395     

Recovery Kinetics of Knee Flexor and Extensor Strength after a Football Match

We examined the temporal changes of isokinetic strength performance of knee flexor (KF) and extensor (KE) strength after a football match. Players were randomly assigned to a control (N = 14, participated only in measurements and practices) or an experimental group (N = 20, participated also in a football match). Participants trained daily during the two days after the match. Match and training overload was monitored with GPS devices. Venous blood was sampled and muscle damage was assessed pre-match, post-match and at 12h, 36h and 60h post-match. Isometric strength as well as eccentric and concentric peak torque of knee flexors and extensors in both limbs (dominant and non-dominant) were measured on an isokinetic dynamometer at baseline and at 12h, 36h and 60h after the match. Functional (KF_ecc/KE_con) and conventional (KF_con/KE_con) ratios were then calculated. Only eccentric peak torque of knee flexors declined at 60h after the match in the control group. In the experimental group: a) isometric strength of knee extensors and knee flexors declined (P<0.05) at 12h (both limbs) and 36h (dominant limb only), b) eccentric and concentric peak torque of knee extensors and flexors declined (P<0.05) in both limbs for 36h at 60°/s and for 60h at 180°/s with eccentric peak torque of knee flexors demonstrating a greater (P<0.05) reduction than concentric peak torque, c) strength deterioration was greater (P<0.05) at 180°/s and in dominant limb, d) the functional ratio was more sensitive to match-induced fatigue demonstrating a more prolonged decline. Discriminant and regression analysis revealed that strength deterioration and recovery may be related to the amount of eccentric actions performed during the match and athletes'' football-specific conditioning. Our data suggest that recovery kinetics of knee flexor and extensor strength after a football match demonstrate strength, limb and velocity specificity and may depend on match physical overload and players'' physical conditioning level.     

Trunk response analysis under sudden forward perturbations using a kinematics-driven model

Accurate quantification of the trunk transient response to sudden loading is crucial in prevention, evaluation, rehabilitation and training programs. An iterative dynamic kinematics-driven approach was used to evaluate the temporal variation of trunk muscle forces, internal loads and stability under sudden application of an anterior horizontal load. The input kinematics is hypothesized to embed basic dynamic characteristics of the system that can be decoded by our kinematics-driven approach. The model employs temporal variation of applied load, trunk forward displacement and surface EMG of select muscles measured on two healthy and one chronic low-back pain subjects to a sudden load. A finite element model accounting for measured kinematics, nonlinear passive properties of spine, detailed trunk musculature with wrapping of global extensor muscles, gravity load and trunk biodynamic characteristics is used to estimate the response under measured sudden load. Results demonstrate a delay of ～200 ms in extensor muscle activation in response to sudden loading. Net moment and spinal loads substantially increase as muscles are recruited to control the trunk under sudden load. As a result and due also to the trunk flexion, system stability significantly improves. The reliability of the kinematics-driven approach in estimating the trunk response while decoding measured kinematics is demonstrated. Estimated large spinal loads highlight the risk of injury that likely further increases under larger perturbations, muscle fatigue and longer delays in activation.     

Trunk muscle reflexes are elicited by small continuous perturbations in healthy subjects and patients with low-back pain

Low-back pain (LBP) has been recognized as the leading cause of disability worldwide. Lumbar instability has been considered as an important mechanism of LBP and one potential contributor to lumbar stability is trunk muscle reflex activity. However, due to the differences in experimental paradigms used to quantify trunk mechanics and trunk reflexes it remains unclear as to what extent the reflex pathway contributes to overall lumbar stability. The goal of this work was to determine to what extent reflexes of various trunk muscles were elicited by the small continuous perturbations normally used to quantify trunk mechanics. Electromyographic (EMG) activity was measured bilaterally from 3 trunk extensor muscles and 3 trunk flexor muscles at four epochs: 25–50 ms, 50–75 ms, 75–100 ms and 100–125 ms following each perturbation. Reflex activity was seen in all muscles as 34 of the 48 muscle-epoch combinations showed a significant reflex response to either perturbations in the forward or backward direction. However, the reflex EMG activity did not correlate with mechanical estimates of the reflex response. Thus, even though reflexes are indeed elicited by the small perturbations used to quantify trunk mechanics, their exact contribution to overall lumbar stability remains unknown.     

The Effects of Vibration and Muscle Fatigue on Trunk Sensorimotor Control in Low Back Pain Patients

Introduction

Changes in sensorimotor function and increased trunk muscle fatigability have been identified in patients with chronic low back pain (cLBP). This study assessed the control of trunk force production in conditions with and without local erector spinae muscle vibration and evaluated the influence of muscle fatigue on trunk sensorimotor control.

Methods

Twenty non-specific cLBP patients and 20 healthy participants were asked to perform submaximal isometric trunk extension torque with and without local vibration stimulation, before and after a trunk extensor muscle fatigue protocol. Constant error (CE), variable error (VE) as well as absolute error (AE) in peak torque were computed and compared across conditions. Trunk extensor muscle activation during isometric contractions and during the fatigue protocol was measured using surface electromyography (sEMG).

Results

Force reproduction accuracy of the trunk was significantly lower in the patient group (CE = 9.81 ± 2.23 Nm; AE = 18.16 ± 3.97 Nm) than in healthy participants (CE = 4.44 ± 1.68 Nm; AE = 12.23 ± 2.44 Nm). Local erector spinae vibration induced a significant reduction in CE (4.33 ± 2.14 Nm) and AE (13.71 ± 3.45 Nm) mean scores in the patient group. Healthy participants conversely showed a significant increase in CE (8.17 ± 2.10 Nm) and AE (16.29 ± 2.82 Nm) mean scores under vibration conditions. The fatigue protocol induced erector spinae muscle fatigue as illustrated by a significant decrease in sEMG median time-frequency slopes. Following the fatigue protocol, patients with cLBP showed significant decrease in sEMG root mean square activity at L4-5 level and responded in similar manner with and without vibration stimulation in regard to CE mean scores.

Conclusions

Patients with cLBP have a less accurate force reproduction sense than healthy participants. Local muscle vibration led to significant trunk neuromuscular control improvements in the cLBP patients before and after a muscle fatigue protocol. Muscle vibration stimulation during motor control exercises is likely to influence motor adaptation and could be considered in the treatment of cLBP. Further work is needed to clearly identify at what levels of the sensorimotor system these gains are achievable.     

The impact of diabetic neuropathy on the distal versus proximal comparison of weakness in lower and upper limb muscles of patients with type 2 diabetes mellitus: a cross-sectional study

Objectives:This study aimed to determine the impact of diabetic neuropathy (dNP) on the distal versus proximal comparison of weakness in lower and upper limb muscles of patients with type 2 Diabetes Mellitus (T2DM).Methods:19 healthy male controls without neuropathy (HC) and 35 male T2DM patients, without dNP (n=8), with sensory dNP (n=13) or with sensorimotor dNP (dNPsm; n=14), were enrolled in this study. Maximal isometric (IM) and isokinetic (IK) muscle strength and IK muscle endurance of the dominant knee, ankle and elbow, and maximal IM handgrip strength were measured by means of dynamometry.Results:Ankle muscle endurance was lower compared to the knee, independently of dNP (p<0.001). Maximal IK ankle muscle strength was also lower compared to the knee, albeit only in dNPsm (p=0.003). No differences were found between maximal IM handgrip and elbow strength.Conclusions:Our results suggest an impact of T2DM -with or without dNP- on lower limb muscle strength more distally than proximally, while this was not observed in the upper limb. The gradient of dNP seemed to be a determining factor for the maximal muscle strength, and not for muscle endurance, in the lower limb.     

Upper body muscle strength and endurance in relation to peak exercise capacity during cycling in healthy sedentary male subjects

The aim of this study was to investigate the relation between upper body muscle strength and endurance, and exercise capacity during an incremental cycle exercise test in sedentary healthy male subjects before and after 6 months of combined supervised group training. Exercise capacity was measured as maximal oxygen consumption (VO?peak) and maximum work rate (WR(peak)). Muscle strength and endurance of the upper body were assessed by bench press and isometric measurement of trunk extensor and flexor maximum voluntary contraction (MVC) and trunk extensor and flexor endurance. Thirty-one subjects were studied before and after the training period. Bench press and trunk extensor MVC correlated to exercise capacity at baseline and after training. Training improved VO?peak and WR(peak). The correlation between trunk extensor MVC and exercise capacity improved after training. Upper body strength may affect exercise capacity by increasing the rider's ability to generate force on the handlebar that can be transmitted to the pedals. Resistance training of the arms, chest, and trunk may help improve cycling performance.     

Effects of Heavy Strength Training on Running Performance and Determinants of Running Performance in Female Endurance Athletes

Purpose

The purpose of the current study was to investigate the effects of adding strength training to normal endurance training on running performance and running economy in well-trained female athletes. We hypothesized that the added strength training would improve performance and running economy through altered stiffness of the muscle-tendon complex of leg extensors.

Methods

Nineteen female endurance athletes [maximal oxygen consumption (VO_2max): 53±3 ml∙kg^-1∙min^-1, 5.8 h weekly endurance training] were randomly assigned to either normal endurance training (E, n = 8) or normal endurance training combined with strength training (E+S, n = 11). The strength training consisted of four leg exercises [3 x 4–10 repetition maximum (RM)], twice a week for 11 weeks. Muscle strength, 40 min all-out running distance, running performance determinants and patellar tendon stiffness were measured before and after the intervention.

Results

E+S increased 1RM in leg exercises (40 ± 15%) and maximal jumping height in counter movement jump (6 ± 6%) and squat jump (9 ± 7%, p < 0.05). This was accompanied by increased muscle fiber cross sectional area of both fiber type I (13 ± 7%) and fiber type II (31 ± 20%) in m. vastus lateralis (p < 0.05), with no change in capillary density in m. vastus lateralis or the stiffness of the patellar tendon. Neither E+S nor E changed running economy, fractional utilization of VO_2max or VO_2max. There were also no change in running distance during a 40 min all-out running test in neither of the groups.

Conclusion

Adding heavy strength training to endurance training did not affect 40 min all-out running performance or running economy compared to endurance training only.     

Trunk muscle coactivation in preparation for sudden load.

Biomechanical stability of the lumbar spine is an important factor in the etiology and control of low-back disorders. A principle component of biomechanical stability is the musculoskeletal stiffening generated by preparatory muscle coactivation. The goal of this investigation was to quantify preparatory behavior, evaluating trunk muscle activity immediately prior to sudden trunk flexion loading during static extension tasks compared to activity observed when subjects were informed no sudden load would occur. Coactive excitation was also examined as a function of fatigue and gender. Results demonstrated increased extensor muscle and flexor muscle coactivation following static fatiguing exertions, potentially compensating for reduced trunk stiffness. Female subjects produced greater flexor antagonism than in the males. No difference in the preparatory coactive muscle recruitment patterns were observed when subjects were expecting a sudden flexion load compared to recruitment patterns observed in similar static postures when subjects were informed no sudden load would be applied. This indicates the neuromuscular system relies greatly on response characteristics for the maintenance of stability in dynamic loading conditions.     

Speed and power-related gene polymorphisms associated with playing position in elite soccer players

Heritability studies on sport-related traits accepted that endurance, speed, power, and strength abilities include an active genetic predisposition to elite soccer participation. This study evaluates the influence of selected genetic variants on performance in speed, power, and strength laboratory tests on a group of elite soccer players, including their playing position. A ninety-nine male elite soccer players were compared to controls (n = 107) and tested for quadriceps and hamstrings isokinetic strength at speed 60°/s, 180°/s, and 300°/s, jump performance, and genotypes of ACTN3 (R577X, rs1815739), ACE (I/D, rs1799752), NOS3 (Glu298Asp, rs1799983), AMPD1 (34C/T, rs17602729), UCP2 (Ala55Val, rs660339), BDKRB2 (+9/-9, rs5810761) and IL1RN (VNTR 86-bp). The ACTN3 XX homozygotes in defenders had lower quadriceps and hamstring isokinetic strength in all tested speeds than ACTN3 RX and RR genotypes (p < 0.05). The ACTN3 RR homozygotes in defenders had higher quadriceps strength in all tested velocities than the RX heterozygotes (p < 0.05). We also found other associations between playing-position in soccer and increased strength of lower limbs for AMPD1 CC and NOS3 Glu/Glu genotypes, and IL1RN*2 allele carriers. Total genetic score regression explained 26% of the variance in jump performance and isokinetic strength. The ACTN3 R allele, NOS3 Glu/Glu genotypes, and IL1RN*2 allele pre-disposed the attackers and defenders playing position in elite soccer, where those positions have higher strength and power measures than midfielders. Midfielders have lower strength and power conditions than other playing positions without relation to strength and power genes.     

Trunk's Natural Inclination Influences Stance Limb Kinetics,but Not Body Kinematics,during Gait Initiation in Able Men

The imposing mass of the trunk in relation to the whole body has an important impact on human motion. The objective of this study is to determine the influence of trunk''s natural inclination - forward (FW) or backward (BW) with respect to the vertical - on body kinematics and stance limb kinetics during gait initiation.Twenty-five healthy males were divided based on their natural trunk inclination (FW or BW) during gait initiation. Instantaneous speed was calculated at the center of mass at the first heel strike. The antero-posterior impulse was calculated by integrating the antero-posterior ground reaction force in time. Ankle, knee, hip and thoraco-lumbar (L5) moments were calculated using inverse dynamics and only peaks of the joint moments were analyzed. Among all the investigated parameters, only joint moments present significant differences between the two groups. The knee extensor moment is 1.4 times higher (P<0.001) for the BW group, before the heel contact. At the hip, although the BW group displays a flexor moment 2.4 times higher (P<0.001) before the swing limb''s heel-off, the FW group displays an extensor moment 3.1 times higher (P<0.01) during the swing phase. The three L5 extensor peaks after the toe-off are respectively 1.7 (P<0.001), 1.4 (P<0.001) and 1.7 (P<0.01) times higher for the FW group. The main results support the idea that the patterns described during steady-state gait are already observable during gait initiation. This study also provides reference data to further investigate stance limb kinetics in specific or pathologic populations during gait initiation. It will be of particular interest for elderly people, knowing that this population displays atypical trunk postures and present a high risk of falling during this forward stepping.     

Changes in intra-abdominal pressure, trunk muscle activation and force during isokinetic lifting and lowering

Intra-abdominal pressure (IAP), force and electromyographic (EMG) activity from the abdominal (intra-muscular) and trunk extensor (surface) muscles were measured in seven male subjects during maximal and sub-maximal sagittal lifting and lowering with straight arms and legs. An isokinetic dynamometer was used to provide five constant velocities (0.12–0.96 m·s^–1) of lifting (pulling against the resistance of the motor) and lowering (resisting the downward pull of the motor). For the maximal efforts, position-specific lowering force was greater than lifting force at each respective velocity. In contrast, corresponding IAPs during lowering were less than those during lifting. Highest mean force occurred during slow lowering (1547 N at 0.24 m·s^–1) while highest IAP occurred during the fastest lifts (17.8 kPa at 0.48–0.96 m·s^–1). Among the abdominal muscles, the highest level of activity and the best correlation to variations in IAP (r=0.970 over velocities) was demonstrated by the transversus abdominis muscle. At each velocity the EMG activity of the primary trunk and hip extensors was less during lowering (eccentric muscle action) than lifting (concentric muscle action) despite higher levels of force (r between –0.896 and –0.851). Sub-maximal efforts resulted in IAP increasing linearly with increasing lifting or lowering force (r=0.918 and 0.882, respectively). However, at any given force IAP was less during lowering than lifting. This difference was negated if force and IAP were expressed relative to their respective lifting and lowering maxima. It appears that the IAP increase primarily accomplished by the activation of the transversus abdominis muscle can have the dual function of stabilising the trunk and reducing compression forces in the lumbar spine via its extensor moment. The neural mechanisms involved in sensing and regulating both IAP and trunk extensor activity in relation to the type of muscle action, velocity and effort during the maximal and sub-maximal loading tasks are unknown.     

Validity of trunk extensor and flexor torque measurements using isokinetic dynamometry

This study aimed to evaluate the validity and test–retest reliability of trunk muscle strength testing performed with a latest-generation isokinetic dynamometer. Eccentric, isometric, and concentric peak torque of the trunk flexor and extensor muscles was measured in 15 healthy subjects. Muscle cross sectional area (CSA) and surface electromyographic (EMG) activity were respectively correlated to peak torque and submaximal isometric torque for erector spinae and rectus abdominis muscles. Reliability of peak torque measurements was determined during test and retest sessions. Significant correlations were consistently observed between muscle CSA and peak torque for all contraction types (r = 0.74−0.85; P < 0.001) and between EMG activity and submaximal isometric torque (r ⩾ 0.99; P < 0.05), for both extensor and flexor muscles. Intraclass correlation coefficients were comprised between 0.87 and 0.95, and standard errors of measurement were lower than 9% for all contraction modes. The mean difference in peak torque between test and retest ranged from −3.7% to 3.7% with no significant mean directional bias. Overall, our findings establish the validity of torque measurements using the tested trunk module. Also considering the excellent test–retest reliability of peak torque measurements, we conclude that this latest-generation isokinetic dynamometer could be used with confidence to evaluate trunk muscle function for clinical or athletic purposes.     

Trunk muscle responses to suddenly applied loads: Do individuals who develop discomfort during prolonged standing respond differently?

Individuals with low back pain or injury (LBP/LBI) have been shown to display altered muscle responses to trunk perturbations; however it is unclear whether these observations are a cause or a result of the LBP/LBI. In this study, a 6.78 kg load was suddenly applied to the hands to perturb the trunk prior to and following a 2-h standing period, during which trunk and hip electromyography (EMG) and centre of pressure (CoP) at the feet were recorded. Seven of the 13 participants developed substantial low back discomfort (LBDiscomfort) during the standing period. These individuals, both pre- and post-standing, showed a greater average number of responsive extensor muscles (3.8 compared to 3.1 in those who did not develop discomfort) and a greater occurrence of extensor muscle response (95–100% of trials) as compared to those who did not develop LBDiscomfort (73–86% of trials). Also, after discomfort developed, these individuals displayed an increased response in their abdominal muscles. This overall increase in trunk musculature activity could either be detrimental by potentially increasing spinal loading leading to LBDiscomfort, or beneficial in that this increased musculature responsiveness may reduce one’s likelihood of developing a future LBI through a pathway of increased spine stability. In either case, these responses indicate motor control characteristics that can distinguish the likelihood of an individual developing LBDiscomfort during common tasks such as prolonged standing.     

Wireless Tri-Axial Trunk Accelerometry Detects Deviations in Dynamic Center of Mass Motion Due to Running-Induced Fatigue

Small wireless trunk accelerometers have become a popular approach to unobtrusively quantify human locomotion and provide insights into both gait rehabilitation and sports performance. However, limited evidence exists as to which trunk accelerometry measures are suitable for the purpose of detecting movement compensations while running, and specifically in response to fatigue. The aim of this study was therefore to detect deviations in the dynamic center of mass (CoM) motion due to running-induced fatigue using tri-axial trunk accelerometry. Twenty runners aged 18–25 years completed an indoor treadmill running protocol to volitional exhaustion at speeds equivalent to their 3.2 km time trial performance. The following dependent measures were extracted from tri-axial trunk accelerations of 20 running steps before and after the treadmill fatigue protocol: the tri-axial ratio of acceleration root mean square (RMS) to the resultant vector RMS, step and stride regularity (autocorrelation procedure), and sample entropy. Running-induced fatigue increased mediolateral and anteroposterior ratios of acceleration RMS (p < .05), decreased the anteroposterior step regularity (p < .05), and increased the anteroposterior sample entropy (p < .05) of trunk accelerometry patterns. Our findings indicate that treadmill running-induced fatigue might reveal itself in a greater contribution of variability in horizontal plane trunk accelerations, with anteroposterior trunk accelerations that are less regular from step-to-step and are less predictable. It appears that trunk accelerometry parameters can be used to detect deviations in dynamic CoM motion induced by treadmill running fatigue, yet it is unknown how robust or generalizable these parameters are to outdoor running environments.     

A Correlational Study of Scoliosis and Trunk Balance in Adult Patients with Mandibular Deviation

Previous studies have confirmed that patients with mandibular deviation often have abnormal morphology of their cervical vertebrae. However, the relationship between mandibular deviation, scoliosis, and trunk balance has not been studied. Currently, mandibular deviation is usually treated as a single pathology, which leads to poor clinical efficiency. We investigated the relationship of spine coronal morphology and trunk balance in adult patients with mandibular deviation, and compared the finding to those in healthy volunteers. 35 adult patients with skeletal mandibular deviation and 10 healthy volunteers underwent anterior X-ray films of the head and posteroanterior X-ray films of the spine. Landmarks and lines were drawn and measured on these films. The axis distance method was used to measure the degree of scoliosis and the balance angle method was used to measure trunk balance. The relationship of mandibular deviation, spine coronal morphology and trunk balance was evaluated with the Pearson correlation method. The spine coronal morphology of patients with mandibular deviation demonstrated an “S” type curve, while a straight line parallel with the gravity line was found in the control group (significant difference, p<0.01). The trunk balance of patients with mandibular deviation was disturbed (imbalance angle >1°), while the control group had a normal trunk balance (imbalance angle <1°). There was a significant difference between the two groups (p<0.01). The degree of scoliosis and shoulder imbalance correlated with the degree of mandibular deviation, and presented a linear trend. The direction of mandibular deviation was the same as that of the lateral bending of thoracolumbar vertebrae, which was opposite to the direction of lateral bending of cervical vertebrae. Our study shows the degree of mandibular deviation has a high correlation with the degree of scoliosis and trunk imbalance, all the three deformities should be clinically evaluated in the management of mandibular deviation.     

Arthroscopically Assisted Combined Anterior and Posterior Cruciate Ligament Reconstruction with Autologous Hamstring Grafts–Isokinetic Assessment with Control Group

Objective

The aim of the study was to: 1) evaluate the differences in pre-post operative knee functioning, mechanical stability, isokinetic knee muscle strength in simultaneous arthroscopic patients after having undergone an anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) with hamstring tendons reconstruction, 2) compare the results of ACL/PCL patients with the control group.

Design

Controlled Laboratory Study.

Materials and Methods

Results of 11 ACL/PCL patients had been matched with 22 uninjured control participants (CP). Prior to surgery, and minimum 2 years after it, functional assessment (Lysholm and IKDC 2000), mechanical knee joint stability evaluation (Lachman and “drawer” test) and isokinetic tests (bilateral knee muscle examination) had been performed. Different rehabilitation exercises had been used: isometric, passive exercises, exercises increasing the range of motion and proprioception, strength exercises and specific functional exercises.

Results

After arthroscopy no significant differences had been found between the injured and uninjured leg in all isokinetic parameters in ACL/PCL patients. However, ACL/PCL patients had still shown significantly lower values of strength in relative isokinetic knee flexors (p = 0.0065) and extensors (p = 0.0171) compared to the CP. There were no differences between groups regarding absolute isokinetic strength and flexors/extensors ratio. There was statistically significant progress in IKDC 2000 (p = 0.0044) and Lysholm (p = 0.0044) scales prior to (44 and 60 points respectively) and after the reconstruction (61 for IKDC 2000 and 94 points for Lysholm).

Conclusions

Although harvesting tendons of semitendinosus and/or gracilis from the healthy extremity diminishes muscle strength of knee flexors in comparison to the CP, flexor strength had improved. Statistically significant improvement of the knee extensor function may indicate that the recreation of joint mechanical stability is required for restoring normal muscle strength. Without restoring normal muscle function and strength, surgical intervention alone may not be sufficient enough to ensure expected improvement of the articular function.