Fatigue and recovery have different effects on knee biomechanics of drop vertical jump between female collegiate and recreational athletes

Background Although fatigue is known as one of the risk factors for noncontact anterior cruciate ligament injury, the effects of fatigue and recovery can be different based on the level of competition. However, it is unknown whether female recreational athletes are susceptible to fatigue or not, compared to female collegiate athletes with greater physical activity. The purpose of the present study was to examine and clarify the effects of fatigue and recovery on knee biomechanics of the drop vertical jump (DVJ) in female recreational athletes compared to female collegiate athletes. Methods Fifteen female collegiate athletes and ten female recreational athletes were enrolled in the current study. All subjects were basketball players and Tegner activity scales were level 9 and 7, respectively. They performed DVJ before and after the fatigue protocol. Three-dimensional knee kinematics and kinetics were collected during landing phase of DVJ. The data after the fatigue protocol (first, second, and third DVJs) were compared with those before the protocol using one-way repeated measures of analysis of variance in each group. Results Fatigue caused significant increase of knee abduction angle at initial contact (IC) and peak abduction moments within 40 ms from IC in female recreational athletes, whereas no increases of these parameters were observed in female collegiate athletes. Moreover, recovery from fatigue seemed to be more slowly in female recreational athletes than in female collegiate athletes as smaller knee flexion moment was observed even in post-fatigue third DVJ only for female recreational athletes. Conclusions Effects of fatigue on DVJ were significantly greater and continued for a longer duration in female recreational athletes compared to female collegiate athletes.

Biomechanical Features of Drop Vertical Jump Are Different Among Various Sporting Activities

Background: Risk for non-contact anterior cruciate ligament (ACL) injury can be assessed based on drop vertical jump (DVJ). However, biomechanics of DVJ should differ with type of various sporting activities. The purpose of the present study was to clarify whether biomechanical features of DVJ are different among various sporting activities in female athletes.Methods: A total of 42 female athletes, including 25 basketball, 8 soccer and 9 volleyball players, participated in the current investigation. DVJ was done for each female athlete using a three-dimensional motion analysis system which consisted of six cameras, two force plates and 46 retro-reflective markers. Kinematic and kinetic data were recorded for both limbs in each athlete. Simultaneously, frontal and sagittal plane views of the DVJ were recorded using high-resolution two different video cameras to evaluate Landing Error Scoring System (LESS) score. Three-dimensional biomechanical parameters at the knee joint and LESS were compared among three different sporting activities.Results: Soccer players had better LESS score, compared to basketball players, while no significantly differences were found between basketball and volleyball players in LESS. In addition, peak knee flexion angle was significantly larger, and knee abduction angle at initial contact (IC), peak knee abduction angle, knee internal rotation angle, and knee abduction moment within 40 milliseconds from IC were significantly smaller in soccer players, compared to basketball players. There were no significantly differences between basketball and volleyball players in all biomechanical parameters.Conclusions: From the present study, female basketball and volleyball players have worse LESS score, greater knee abduction angle and moment, compared to female soccer players. Thus, female basketball and volleyball players are likely to have the increased risk of non-contact ACL injury during DVJ, compared to soccer players. DVJ may be useless as a screening tool of non-contact ACL injury for soccer players. Biomechanics of DVJ depends on characteristics of the athlete's primary sport.

Modification of a simplified hip joint simulator into an ISO 14242-1 compliant design and a comparison of wear test results

The ISO 14242-1 standard for hip joint simulator wear testing specifies a set of test conditions for the simulation of normal level walking in optimal conditions. Since some of the established simulators, such as the 12-station HUT-4, are not ISO 14242-1 compliant, the present study was carried out to answer the following question. Does wear produced in ISO 14242-1 conditions differ from that obtained earlier with the simplified HUT-4 hip joint simulator for similar specimens in normal level walking, optimal conditions? The HUT-4 hip joint simulator was made ISO compliant by an implementation of a number of modifications. One of the modifications was the design and construction of a novel servo-electric load actuator with proven dynamic response. The other modifications were related to the Euler sequence of motions, acetabular abduction angle, enclosure of the lubricant chamber, and temperature control. A 5 million-cycle wear test with thin, large-diameter VEXLPE liners resulted in a wear rate close to that obtained earlier with the HUT-4. The burnished bearing surface in both tests was in agreement with clinical retrieval studies. It appeared that a more simple, inexpensive hip joint simulator can reproduce clinical wear mechanisms. However, the simulator must meet certain basic requirements, such as the correct type of multidirectional relative motion, for which biaxial motion is sufficient. The present study was not intended to show a similarity in wear produced by the ISO 14242-1 and HUT-4 wear test systems.

Drop Landing Biomechanics in Individuals With and Without a Concussion History

Research has identified an increased risk of lower extremity injury postconcussion, which may be due to aberrant biomechanics during dynamic tasks. The purpose of this study was to compare the drop landing biomechanics between individuals with and without a concussion history. Twenty-five individuals with and 25 without a concussion history were matched on age (±3 y), sex, and body mass index (±1 kg/m2). Three-dimensional landing biomechanics were recorded to obtain dependent variables (peak vertical ground reaction force, loading rate, knee flexion angle and external moment, knee abduction angle and external moment, and knee flexion and abduction angle at ground contact). A 1-way multivariate analysis of variance compared outcomes between groups. There was no difference in drop landing biomechanics between individuals with and without a concussion history (F10,39 = 0.460, P = .877, Wilk Λ = .918). There was an effect of time since concussion on knee flexion characteristics. Time since most recent concussion explained a significant amount of variation in both peak (ΔR2 = .177, β = −0.305, ΔP = .046) and initial ground contact (ΔR2 = .292, β = −0.204, ΔP = .008) knee flexion angle after covarying for sex and body mass index. Therefore, time since concussion should be considered when evaluating biomechanical patterns.

Effect of Etanercept Combined with Synovectomy on Function and Serum Levels of Associated Factors in AS Patients with Coexisting Coxarthrosis

Objective To investigate the clinical effect and value of etanercept combined with arthroscopic synovectomy in the treatment of ankylosing spondylitis (AS) complicated with coxarthrosis. Methods 66 patients with AS complicated with coxarthrosis admitted in our hospital were taken as the study objects and were randomly divided into two groups with random number table: test group (n = 33) and control group (n = 33). The arthroscopic synovectomy was given to both groups. The control group was given basic anti-inflammatory and analgesic measures, promoting blood circulation and detumescent measures after surgery, and the test group was added with etanercept on the basis of the control group. Changes in scores of coxae function, serum transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) at different time after operation were compared between the two groups. Results There was no significant difference in Harris score between the test group and the control group before operation (P>0.05). The Harris score of the test group was higher than that of the control group 3 months after operation and 6 months after operation (P<0.05). There was no statistically significant difference in the determination of flexion angle and abduction angle of coxae between the test group and the control group before operation (P>0.05). The flexion angle and abduction angle of coxae of the test group were higher than that of the control group 6 months after operation (P<0.05). The difference of measured values of serum levels TGF-β1, TNF-α, IL-6, CRP and ESR in the test group and the control group had no statistical significance (P>0.05). The determination values of serum levels TGF-β1, TNF-α, IL-6, CRP and ESR in the test group were lower than those in the control group at 3 months after operation (P<0.05). Conclusion Etanercept combined with arthroscopic synovectomy for the treatment of AS complicated with coxarthrosis is beneficial to regulate the level of related cytokines and promote the recovery of postoperative joint function.

Immediate Effect of Anterior Cruciate Ligament Protective Knee Taping on Knee Landing Mechanics and Muscle Activations during Side Hops

Athletic taping is widely used in sports to prevent injury. However, the effect of anterior cruciate ligament (ACL) protective taping on neuromuscular control during dynamic tasks remains unclear. Therefore, this study aimed to investigate the immediate effect of ACL protective taping on landing mechanics and muscle activations during side hops in healthy individuals. Fifteen healthy individuals (11 males and 4 females; age, 23.1 ± 1.4 years; height, 175.1 ± 10.4 cm; weight, 66.3 ± 11.2 kg) volunteered to participate in this study. Landing mechanics and muscle activations were measured while each participant performed single-leg hops side-to-side for ten repetitions with and without taping. An optical motion capture system and two force plates were used to collect the kinematic and kinetic data during the side hops. Surface electromyogram recordings were performed using a wireless electromyography system. Paired t-tests were performed to determine the differences in landing mechanics and muscle activations between the two conditions (taping and non-taping). The level of significance was set at p < 0.05. Compared with the non-taping condition, participants landed with a smaller knee abduction angle, greater knee external rotation angle, and smaller knee extensor moment in the taping condition. Given that greater knee abduction, internal rotation, and knee extension moment are associated with a greater risk of ACL injury, our findings suggest that ACL protective taping can have an immediate effect on dynamic knee stability. Clinicians should consider using ACL protective taping to facilitate the use of favorable landing mechanics for ACL injuries.

Relationships between Hip Flexibility and Pitching Biomechanics in Adolescent Baseball Pitchers

Context: Inadequate hip active range of motion (AROM) may stifle the energy flow through the kinematic chain and decrease pitching performance while increasing the risk for pitcher injury. Objective: To examine the relationship of hip AROM and pitching biomechanics during a fastball pitch in adolescent baseball pitchers. Design: Cross-Sectional study. Setting: Biomechanics laboratory. Participants: A voluntary sample of 21 adolescent baseball pitchers (16.1 ± 0.8 yrs.; 183.9 ± 5.2 cm; 77.9 ± 8.3 kg). Main Outcome Measure (s): Bilateral hip internal rotation (IR), external rotation (ER), flexion, extension, and abduction AROM were measured. Three-dimensional biomechanics were assessed as participants threw from an indoor pitching mound to a strike zone net at regulation distance. Pearson correlation coefficients were used to determine correlations between hip AROM and biomechanical metrics. Results: Statistically significant negative correlations were found at foot contact between back hip ER AROM and back hip abduction angle (p=0.030, r=−0.474), back hip ER AROM and torso rotation angle (p=0.032, r=−0.468),and back hip abduction AROM and lead hip abduction angle (p=0.037, r=−0.458). Back hip extension AROM was positively correlated with increased stride length (p=0.043, r=0.446). Lead hip abduction AROM was also positively correlated with normalized elbow varus torque (p=0.034, r=0.464). Conclusions: There were several relationships between hip AROM and biomechanical variables during the pitching motion. The findings support the influence hip AROM can have on pitching biomechanics. Overall, greater movement at the hips allows for the kinematic chain to work at its maximal efficiency, increasing pitch velocity potential.

Robotic Shoulder Rehabilitation With the Hybrid Assistive Limb in a Patient With Delayed Recovery After Postoperative C5 Palsy: A Case Report

C5 palsy is a serious complication that may occur after cervical spine surgery; however, standard procedures for shoulder rehabilitation for patients with postoperative C5 palsy have not yet been established. We used a wearable robot suit Hybrid Assistive Limb (HAL) in a patient with delayed recovery after postoperative C5 palsy and conducted shoulder abduction training with the HAL. A 62-year-old man presented with weakness in his left deltoid muscle 2 days after cervical spine surgery. He experienced great difficulty in elevating his left arm and was diagnosed with postoperative C5 palsy. Seven months after surgery, shoulder abduction training with a HAL was initiated. In total, 23 sessions of shoulder HAL rehabilitation were conducted until 26 months after surgery. His shoulder abduction angle and power improved at every HAL session, and he was able to fully elevate his arm without any compensatory movement after the 23rd session, suggesting that the HAL is a useful tool for shoulder rehabilitation in patients with postoperative C5 palsy. We employed shoulder HAL training for a patient with delayed recovery from postoperative C5 palsy and achieved complete restoration of shoulder function. We believe that the HAL-based training corrected the erroneous motion pattern of his paralyzed shoulder and promoted errorless motor learning for recovery. Our collective experience suggests that shoulder HAL training could be an effective therapeutic tool for patients with postoperative C5 palsy.

A Systematic Review and Meta-Analysis of the SuperPATH Approach in Hip Arthroplasty

Objective. To compare the clinical and radiographic results of the supercapsular percutaneously assisted total hip (SuperPATH) approach and the conventional approach in hip arthroplasty. Design. Based on a prepublished protocol (PROSPERO: CRD42020177717), we searched PubMed, Embase, and Cochrane for relevant literatures up to January 30, 2021. The methodological qualities were assessed using the guidelines provided by the Cochrane Collaboration for Systematic Reviews. Randomized- or fixed-effect models were used to calculate the weighted mean difference (WMD) or odds ratio (OR), respectively, for continuous and dichotomous variables. Results. 6 articles were included in the study, and 526 patients were selected, which included 233 cases in the SuperPATH groups and 279 cases in the conventional groups, and 4 cases performed two surgeries in succession. The SuperPATH group demonstrated shorter incision length ( WMD = − 7.87 , 95% CI (−10.05, −5.69), P < 0.00001 ), decreased blood transfusion rate ( OR = 0.48 , 95% CI (0.25, 0.89), P = 0.02 ), decreased visual analogue scale (VAS) ( WMD = − 0.40 , 95% CI (−0.72, −0.08), P = 0.02 ), and higher Harris hip score (HHS) ( WMD = 1.98 , 95% CI (0.18, 3.77), P = 0.03 ) than the conventional group. However, there was no difference in VAS ( P = 0.14 ) and HHS ( P = 0.86 ) between the two groups 3 months later, nor in the acetabular abduction angle ( P = 0.32 ) in either group. Conclusions. SuperPATH, as a minimally invasive approach with its reduced tissue damage, quick postoperative recovery, and early rehabilitation, demonstrates the short-term advantages of hip arthroplasty. As the evidences in favor of the SuperPATH technique were limited in a small number of studies and short duration of follow-up, more research is required to further analyze its long-term effect.

Three-dimensional motion analysis of ten common Asian sitting positions in daily living and factors affect range of hip motions

Background Sitting involves many activities of daily life and requires most motion in the hip joint. Asians have more hip flexion and external rotation motions than Westerners owing to cultural and lifestyle differences. Being aware of the normal range of hip motion is essential in clinical practice. Limited research has focused on the hip motions of common sitting positions. The objective was to determine the hip motions of 10 common sitting positions, and to determine whether gender or being overweight affects the range of hip motions. Methods An experimental cross-sectional study was conducted to determine hip motions by using a standard, three-dimensional, motion-analysis system. Healthy subjects performed 10 sitting positions during 3 trials. All hip-kinematic data were measured on the dominant leg of each participant, except for the right- and left-monk positions (both hips were analyzed). Density plots were constructed and statistical analyses were performed to detect the differences between groups (male and female; non-overweight and overweight). Results The 48 participants comprised 24 males and 24 females. Most were right-leg dominant (45 participants, 93.8%). Of the 22 participants in the overweight group (body mass index ≥23 kg/m2), 18 (75%) were male. Squatting showed the highest flexion angle (99.7°, 47.3°–122°). Cross-legged sitting had the highest abduction angle (28.9°, 9.9°–45.7°) and the largest external rotation angle (62°, 37.6°–81.7°). In the female group, there were trends toward a greater flexion angle (4 out of 10 sitting positions) and a smaller abduction angle (6 out of 9 positions), with P values < 0.05. As to body weight, the overweight participants had a smaller flexion angle but a greater abduction angle, with 5 out of 9 positions having a P value < 0.05. Kinematic data of the transverse plane revealed that the heterogeneity of the rotational angles depended on the sitting position. Conclusions This study provided the functional hip motions of common Asian sitting positions. The kinematic data can be utilized in clinical practice as reference values to determine safe positions. Gender and being overweight affected the hip angles in the sagittal and frontal planes. Trial registration Number TCTR20181021004, retrospectively registered at the Thai Clinical Trials Registry (http//:www.clinicaltrials.in.th).