Maximum Knee Flexion Angle Research Articles

Characteristics of Patella Alignment and Reduced Maximum Knee Flexion Angle in Total Knee Arthroplasty Patients

Characteristics of Patella Alignment and Reduced Maximum Knee Flexion Angle in Total Knee Arthroplasty Patients

Influence of the forehand stance on knee biomechanics: Implications for potential injury risks in tennis players

ABSTRACT The open stance forehand has been hypothesized to be more traumatic for knee injuries in tennis than the neutral stance forehand. This study aims to compare kinematics and kinetics at the knee during three common forehand stroke stances (attacking neutral stance ANS, attacking open stance AOS, defensive open stance DOS) to determine if the open stance forehand induces higher knee loadings and to discuss its potential relationship with given injuries. Eight advanced tennis players performed eight repetitions of forehand strokes with each stance (ANS: forward run and stroke with feet parallel with the hitting direction, AOS: forward run and stroke with feet perpendicular to the hitting direction, DOS: lateral run and stroke with feet perpendicular to the hitting direction) at maximal effort. All the trials were recorded with an optoelectronic motion capture system. The flexion-extension, abduction-adduction, external-internal rotation angles, intersegmental forces and torques of the right knee were calculated. Ground reaction forces were measured with a forceplate. The DOS increases vertical GRF, maximum knee flexion and abduction angles, range of knee flexion-extension, peak of compressive, distractive and medial knee forces, peak of knee abduction and external rotation torques. Consequently, the DOS appears potentially more at risk for given knee injuries.

Sagittal knee kinematics in relation with the posterior tibia slope during jump landing after an anterior cruciate ligament reconstruction

PurposeAn increased posterior tibia plateau angle is associated with increased risk for anterior cruciate ligament injury and re-rupture after reconstruction. The aims of this study were to determine whether the tibia plateau angle correlates with dynamic anterior tibia translation (ATT) after an anterior cruciate ligament reconstruction and whether the tibia plateau angle correlates with aspects of knee kinematics and kinetics during jump landing.MethodsThirty-seven patients after anterior cruciate ligament reconstruction with autograft hamstring tendon were included. Knee flexion angle and knee extension moment during single leg hops for distance were determined using a motion capture system and the dynamic ATT with its embedded method. The medial and lateral posterior tibia plateau angle were measured using MRI. Moreover, passive ATT was measured using the KT-1000 arthrometer.ResultsA weak negative correlation was found between the maximal dynamic ATT and the medial tibia plateau angle (p = 0.028, r = − 0.36) and between the maximal knee flexion angle and the lateral tibia plateau angle (p = 0.025, r = − 0.37) during landing. Patients with a smaller lateral tibia plateau angle show larger maximal knee flexion angle during landing than the patients with larger lateral tibia plateau angle. Also, the lateral tibia plateau angle is associated the amount of with muscle activity.ConclusionThe posterior medical tibia plateau angle is associated with dynamic ATT. The maximal knee flexion angle and muscle activity are associated with the posterior lateral tibia plateau angle.Level of evidenceIII

Relationship between Quadriceps Tendon Young's Modulus and Maximum Knee Flexion Angle in the Swing Phase of Gait in Patients with Severe Knee Osteoarthritis.

Background and objectives: Decreased knee flexion in the swing phase of gait can be one of the causes of falls in severe knee osteoarthritis (OA). The quadriceps tendon is one of the causes of knee flexion limitation; however, it is unclear whether the stiffness of the quadriceps tendon affects the maximum knee flexion angle in the swing phase. The purpose of this study was to clarify the relationship between quadriceps tendon stiffness and maximum knee flexion angle in the swing phase of gait in patients with severe knee OA. Materials and Methods: This study was conducted from August 2018 to January 2020. Thirty patients with severe knee OA (median age 75.0 (interquartile range 67.5–76.0) years, Kellgren–Lawrence grade: 3 or 4) were evaluated. Quadriceps tendon stiffness was measured using Young’s modulus by ShearWave Elastography. The measurements were taken with the patient in the supine position with the knee bent at 60° in a relaxed state. A three-dimensional motion analysis system measured the maximum knee flexion angle in the swing phase. The measurements were taken at a self-selected gait speed. The motion analysis system also measured gait speed, step length, and cadence. Multiple regression analysis by the stepwise method was performed with maximum knee flexion angle in the swing phase as the dependent variable. Results: Multiple regression analysis identified quadriceps tendon Young’s modulus (standardized partial regression coefficients [β] = −0.410; p = 0.013) and gait speed (β = 0.433; p = 0.009) as independent variables for maximum knee flexion angle in the swing phase (adjusted coefficient of determination = 0.509; p < 0.001). Conclusions: Quadriceps tendon Young’s modulus is a predictor of the maximum knee flexion angle. Clinically, decreasing Young’s modulus may help to increase the maximum knee flexion angle in the swing phase in those with severe knee OA.

Single-Leg Squat After Anterior Cruciate Ligament Reconstruction: An Analysis of the Knee Valgus Angle at 6 and 12 Months.

Background:Deficits in neuromuscular control are common after anterior cruciate ligament (ACL) reconstruction and may be associated with further knee injury. The knee valgus angle during a single-leg squat (SLS) is one measure of neuromuscular performance.Purpose:To determine whether the knee valgus angle during SLS changes between 6 and 12 months after ACL reconstruction and to assess how the operative knee valgus angle compares with that of the contralateral side.Study Design:Case series; Level of evidence, 4.Methods:A cohort of 100 patients with uninjured contralateral knees were assessed at 6 and 12 months after primary hamstring autograft ACL reconstruction. Participants performed the SLS on each leg, and the knee valgus angle was measured via frame-by-frame video analysis at 30° of flexion and at each patient’s maximum knee flexion angle.Results:For the operative limb at 30° of flexion, a small but statistically significant reduction was noted in the valgus angle between 6 and 12 months (5.46° vs 4.44°; P = .002; effect size = 0.24). At 6 months, a slightly higher valgus angle was seen in the operative limb compared with the nonoperative limb (5.46° vs 4.29°; P = .008; effect size = 0.27). At maximum flexion, no difference was seen between limbs in the valgus angle at either 6 or 12 months, and no change was seen in the operative limb between 6 and 12 months. At 6 months and 30° of knee flexion, 13 patients had a valgus angle greater than 10°. This group also had a higher mean valgus angle in the contralateral limb compared with the contralateral limb in the other 87 patients (8.5° vs 3.65°; P < .001).Conclusion:During a controlled SLS, the knee valgus angle remained essentially constant, and minimal limb asymmetries were present over the 6- to 12-month postoperative period, a time when athletes typically increase their activity levels. Whether changes or asymmetries will be seen with more dynamically challenging tasks remains to be determined. When present, high valgus angles were commonly bilateral.

Powered knee and ankle prosthesis with indirect volitional swing control enables level-ground walking and crossing over obstacles.

Powered prostheses aim to mimic the missing biological limb with controllers that are finely tuned to replicate the nominal gait pattern of non-amputee individuals. Unfortunately, this control approach poses a problem with real-world ambulation, which includes tasks such as crossing over obstacles, where the prosthesis trajectory must be modified to provide adequate foot clearance and ensure timely foot placement. Here, we show an indirect volitional control approach that enables prosthesis users to walk at different speeds while smoothly and continuously crossing over obstacles of different sizes without explicit classification of the environment. At the high level, the proposed controller relies on a heuristic algorithm to continuously change the maximum knee flexion angle and the swing duration in harmony with the user's residual limb. At the low level, minimum-jerk planning is used to continuously adapt the swing trajectory while maximizing smoothness. Experiments with three individuals with above-knee amputation show that the proposed control approach allows for volitional control of foot clearance, which is necessary to negotiate environmental barriers. Our study suggests that a powered prosthesis controller with intrinsic, volitional adaptability may provide prosthesis users with functionality that is not currently available, facilitating real-world ambulation.

무릎 스트랩과 테이핑 적용이 배구선수의 외발 착지에서 슬개건 통증과 하지 동역학 및 운동학에 미치는 영향

The primary purpose of this study was to compare patellar tendon pain and low extremity kinetics and kinematics of male high school volleyball players on one-leg landing after applying a strap, C-tape, and E-tape, respectively. A total of 16 male high school volleyball players who had no history of lower extremity injury at least for 3 months were recruited(age: 16.37±1.08years, height: 185.56±5.52cm, weight: 76.81±8.52kg). Each participant were alternately equipped with a strap, C-tape, or E-tape on each patellar tendon, and visual analogue scale(VAS) was measures during one leg landing. Maximal knee flexion angle, range of motion, angular velocity, moment, and maximal ground reaction force at the hip, knee, and ankle joint were assessed after each application using 3 dimensional motion analyses. Statistical analyses were done with one-way repeated measure ANOVA and post-hoc analysis. The VAS of strap(2.56±1.45) and C-tape(2.87±1.31) were lower than that of E-tape(3.50±1.31; each p.001 and p=.007). The mean angular velocity of the knee flexion (285.77±88.60deg/s) was significantly higher in strap than in E-tape(242.68±61.64deg/s; p=.026). In summary, it appeared that the application of strap or C-tape was related to effectively reducing patellar tendon pain. Additionally, it could be postulated that the application of a strap attributed to the increase of knee flexion angular velocity during one-leg landing.

Implant Alignment and Patient Factors Affecting the Short-Term Patient-Reported Clinical Outcomes after Oxford Unicompartmental Knee Arthroplasty.

This study aims at clarifying implant alignment and other patient factors' influence on clinical outcomes, particularly on patient-reported outcomes (PRO), following Oxford unicompartmental knee arthroplasty (OUKA). A total of 142 patients after OUKA were divided into two groups according to the validated Japanese version of the knee injury and osteoarthritis outcome score (KOOS) for each subscale of pain, symptoms, and activities of daily living (ADL) at postoperative year 1 and 2: group 1 had ≥80 scores and group 2 had <80 scores. Postoperative clinical and radiographical findings were then compared among groups in each subscale. Using postoperative year 1 and 2 data, a multivariable logistic regression analysis was conducted to clarify factors for clinical outcomes' improvement. In the analysis of KOOS subscale of symptoms at postoperative year 1, gender distribution, preoperative body mass index, and postoperative maximum knee flexion angles differed significantly among groups. In the analysis for KOOS subscale of ADL, significant differences were observed in postoperative tibial component varus angles. Multivariable logistic regression analysis revealed that all of these parameters significantly related to ≥80 KOOS scores of each subscale at postoperative year 1. Additionally, at postoperative year 2, larger postoperative knee flexion angles and tibial component varus angles related to ≥80 KOOS subscale of symptoms and ADL were observed. In conclusion, tibial component's larger varus alignment was associated with the better PRO at both 1 and 2 years after OUKA. Importantly, larger postoperative knee flexion angle helped achieve good short-term PRO after OUKA.

Iterative Adjustment of Stimulation Timing and Intensity During FES-Assisted Treadmill Walking for Patients After Stroke.

Functional electric stimulation (FES) is a common intervention to correct foot drop for patients after stroke. Due to the disturbances from internal time-varying muscle characteristics under electrical stimulation and external environmental uncertainties, most of the existing FES system used pre-set stimulation parameters and cannot achieve good gait performances during FES-assisted walking. Therefore, an adaptive FES control system, which used the iterative learning control to adjust the stimulation intensity based on kinematic data and a linear model to modulate the stimulation timing based on walking speed during FES-assisted treadmill walking, was designed and tested on ten patients with foot drop after stroke. In order to examine its orthotic effects, the kinematic data of the patients using the proposed control strategy were collected and compared with the data of the same patients walking using other three FES control strategies, including (1) constant pre-set stimulation intensity and timing, (2) constant pre-set stimulation intensity with speed-adaptive stimulation timing and (3) walking without FES intervention. The error between the maximum ankle dorsiflexion angle during swing phase and the target angle using the proposed control strategy was the smallest among the four conditions. Moreover, there was no significant difference in the ankle plantar flexion angle at the toe-off event and the maximum knee flexion angle during swing phase between the proposed control strategy and walking without FES. In summary, the proposed control strategy can improve FES-assisted walking performances through adaptive modulation of stimulation timing and intensity when coping with variation, and may have good potential in clinic.

Correlation Between Quadriceps, Hamstring, Tibialis Anterior, and Gastrocnemius Muscle Activation, With Knee Flexion Angle In Basketball Athlete While Performing Double-Leg Landing Task

ABSTRACTBackground: Anterior cruciate ligament (ACL) injury cause great disability for athlete. Recent focus of ACL injury management is on prevention by identifying the risk factors. Most of basketball injury mechanism is non-contact, related to landing process with small knee flexion angle. Muscle activation and its ratio, which control movement pattern in sagittal plane, are said to play a role in dynamic movement such as landing.Aims: The purpose of this study is to analyze the correlation between muscles activation and their activation ratio of quadriceps, hamstring, tibialis anterior and gastrocnemius with knee flexion angle of basketball athlete while performing double-leg landing task.Material and methods: This study was an observational analytic, cross sectional study. Study subjects was basketball athletes age 16 – 25 years in Surabaya. Measurements of knee flexion angle done with digital measurements of reflective marker, and muscle activation was measured with sEMG while performing double-leg landing task.Result: There was no significant correlation between maximum knee flexion angle and muscle activation of quadriceps (p=0,562), hamstring (p=0,918), tibialis anterior (p=0,394) and gastrocnemius (p=0,419). There was also no significant correlation between maximum knee flexion angle and the muscle activation ratio of quadriceps-hamstring (p=0,347), quadriceps-tibialis (p=0,139), quadriceps-gastrocnemius (p=0,626), hamstring-tibialis anterior (p=0,365), hamstring-gastrocnemius (p=0,867), and tibialis anterior-gastrocnemius (p=0,109).Conclusions: There was no correlation between muscle activation and muscle activation ratio of quadriceps, hamstring, tibialis anterior and gastrocnemius with maximum knee flexion angle in basketball athlete while performing double-leg landing task.

Correlation Between Quadriceps, Hamstring, Tibialis Anterior, and Gastrocnemius Muscle Activation, With Knee Flexion Angle In Basketball Athlete While Performing Double-Leg Landing Task

ABSTRACTBackground: Anterior cruciate ligament (ACL) injury cause great disability for athlete. Recent focus of ACL injury management is on prevention by identifying the risk factors. Most of basketball injury mechanism is non-contact, related to landing process with small knee flexion angle. Muscle activation and its ratio, which control movement pattern in sagittal plane, are said to play a role in dynamic movement such as landing.Aims: The purpose of this study is to analyze the correlation between muscles activation and their activation ratio of quadriceps, hamstring, tibialis anterior and gastrocnemius with knee flexion angle of basketball athlete while performing double-leg landing task.Material and methods: This study was an observational analytic, cross sectional study. Study subjects was basketball athletes age 16 – 25 years in Surabaya. Measurements of knee flexion angle done with digital measurements of reflective marker, and muscle activation was measured with sEMG while performing double-leg landing task.Result: There was no significant correlation between maximum knee flexion angle and muscle activation of quadriceps (p=0,562), hamstring (p=0,918), tibialis anterior (p=0,394) and gastrocnemius (p=0,419). There was also no significant correlation between maximum knee flexion angle and the muscle activation ratio of quadriceps-hamstring (p=0,347), quadriceps-tibialis (p=0,139), quadriceps-gastrocnemius (p=0,626), hamstring-tibialis anterior (p=0,365), hamstring-gastrocnemius (p=0,867), and tibialis anterior-gastrocnemius (p=0,109).Conclusions: There was no correlation between muscle activation and muscle activation ratio of quadriceps, hamstring, tibialis anterior and gastrocnemius with maximum knee flexion angle in basketball athlete while performing double-leg landing task.

Varus kinematics at knee flexion affect clinical outcomes of unicompartmental knee arthroplasty: Intraoperative navigation-based kinematics evaluation

BackgroundThe aim of the study was to investigate the effects of navigation-based varus or axial rotational alignment through knee flexion on patient reported outcomes or the maximum flexion angle of unicompartmental knee arthroplasty (UKA). MethodsData were retrospectively collected from 46 knees that underwent UKA for medial unicompartmental knee osteoarthritis. An image-free knee navigation system was used in all cases, and intraoperative varus and axial rotational alignment at every knee flexion angle were recorded before and after implantation. All patients completed the Knee injury and Osteoarthritis Outcome Score (KOOS) at final follow-up. By varus or valgus at 0° knee flexion, the knees were subdivided into two groups (varus at 0° group, varus above the median value; neutral at 0° group, varus equal to or below the median value). By varus or valgus at 90° knee flexion, patients were similarly subdivided into two groups (varus at 90° group; neutral at 90° group). The maximum knee flexion angle was measured 3 months after surgery. ResultsThere were no differences in the KOOS between the neutral at 0° group and the varus at 0° group. However, the KOOS activity score (79 ± 17 vs 69 ± 16, p = 0.02) and the KOOS total score (72 ± 17 vs 65 ± 15, p = 0.03) of the neutral at 90° group were better than those of the varus at 90° group. The alignment and the maximum knee flexion angle 3 months after surgery were not correlated. ConclusionVarus at 0° knee flexion and axial rotational alignment did not affect the clinical outcomes of UKA. Patient reported outcomes was better for the neutral knees with less varus at 90° knee flexion than for varus knees.

Performance analysis of the flip turn in swimming: The relationship between pressures and performance times

This study examined the effects of pressure and other kinetic variables on freestyle flip turn performance. It was hypothesized that an increase in average and peak pressure, and a decrease in the magnitude difference between left and right foot pressure, would result in an improved performance of a swimmer as they performed a flip turn. Ten University level (varsity) swimmers performed five freestyle flip turns using their competition technique. Data were collected from a pressure pad mounted to the vertical wall of the pool and from an underwater camera in the sagittal plane. A negative correlation of .58 and .67 was seen for average and peak pressures respectively when compared to five-meter performance times. Average contact area throughout the push-off phase compared to average and maximum load was .94 and .88. An increase in average contact area from 40 cm 2 to 50 cm 2 resulted in a 26% increase in maximum load. No difference in performance was seen for varying maximum knee flexion angles. Differences between pressure magnitudes between left and right foot did not impact the five-meter performance time. Therefore, increased average contact area throughout the push-off phase caused higher average and maximum loads, and to a lesser extent average and peak pressures. Increases in pressure and load resulted in an improved five-meter performance time. It is concluded that flip turn performance increases through higher contact area with the feet when pushing off the wall.

Kinematic Analysis of Support Phase Characteristics in Women Race Walking

Race walking requires a great deal of effort to compete successfully which includes a unique combination of technique, extreme physical exertion and mental focus. Unlike running, race walking is composed by support phase (heel strike, mid-stance and toe off) and swing phase. The aim of this study was to analyze the association between different kinematic characteristics of support phase during race walking and walking velocity. The rules of race walking demand that no visible flight time should occur and the stance leg must be straightened from initial contact to midstance. Previous research has not examined whether these rules also have an effect on walking performance and what consequences might arise. Top ten (U-20 Girls) finishers of 10000m race walk discipline, 33^rd National Junior Athletic Championships, 2017 held at Acharya Nagarjuna University, Vijaywada, A. P. India were recorded by using two Nikon digital 4K camcorders (60 Hz) mounted on rigid tripods were placed alongside of the course at approximately 90° to the plane of motion. The junior athletes were analyzed by using motion analysis software (KINOVEA 0.8.27). Descriptive statistics and Pearson Product Moment Correlation coefficient (p<0.05) were employed for statistical calculation. The tabulation of data was done by using the IBM SPSS 25 software. The result of the study revealed that, women athlete’s performance were affected by the long contact phase duration (Mean=0.33 s (±) 0.05). This factor relativity creates hindrances in propulsive phase. A negative association (r= -0.49) found between contact time and average speed. As expected, due to the technical rules of this discipline knee angel at heel contact is significantly correlated with velocity as the calculated r value was 0.709* (Critical value at 8 df r = 0.632). Whereas, at mid stance phase a negative correlation found between knee angle and walking performance that sketch a hyper extended knee. However, a positive linear relationship found in variables like, hip angle, elbow angle at heel contact and mid stance phase with walking velocity. But, a less economical technique observed in toe off phase for almost every variable as those were negatively associated with mean speed, and so a balance between those fundamental techniques of support phase variables is advisable. The race walkers had shorter swing times, longer contact times, and smaller maximum knee flexion angles (152° ± 7.32) than the distance runners. The smaller knee flexion angles in race walkers meant they experienced greater swing leg moment of inertia than the distance runners.

Gait analysis after total knee arthroplasty assisted by three-dimensional printing navigation template

To explore the gait trajectory characteristics of patients after total knee arthroplasty (TKA) assisted by three-dimensional (3D) printing navigation template. Twenty female patients (20 knees) with knee osteoarthritis who were treated with TKA assisted by 3D printing navigation template between February 2017 and February 2018 were selected as the 3D printing group. The patients were 50-69 years old, with an average age of 57.2 years. The disease duration was 4-7 years, with an average of 5.6 years. The osteoarthritis was classified as Kellgren-Lawrence Ⅲ level in 5 cases and Ⅳ level in 15 cases. The preoperative hip-knee-ankle angle (HKA) was (170.8±5.6)°. All patients were varus deformity. According to age and affected side, 20 healthy female volunteers were selected as the control group. The volunteers were 51-70 years old, with an average age of 56.7 years. Preoperative HKA was (178.8±0.6)°. There was significant difference in HKA between the two groups ( P>0.05). The HKA, Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and visual analogue scale (VAS) scores of the 3D printing group before and after operation were compared. At 6 months after operation, the gait trajectory characteristics of 3D printing group and control group were analyzed by Vicon gait capture system. The kinematics parameters included velocity, cadence, stride length, maximum knee flexion angle (stance), minimum knee flexion angle (stance), maximum knee flexion angle (swing), mean hip rotation angle (stance), mean ankle rotation angle (stance). The incisions of 3D printing group healed by first intention, with no complications. All patients were followed up 7-12 months (mean, 9.0 months). The WOMAC and VAS scores at 6 months after operation were significant lower than those before operation ( P<0.05). The HKA was (178.8±0.8)° at 4 weeks after operation and the difference was significant when compared with that before operation ( t=39.203, P=0.000). The position of the prosthesis was good. The femoral posterior condyle osteotomy line, surgical transepicondylar axis, and patella transverse line were parallel, varus deformity was corrected, and lower limb alignment was restored to neutral position. Gait analysis at 6 months after operation showed that the differences in all kinematics parameters between the two groups were significant ( P<0.05). Assisted by 3D printing navigation template, TKA can alleviate pain symptoms and correct deformity, with satisfactory early effectiveness. Compared with healthy people, the early postoperative gait of the patients were characterized by decreasing velocity, cadence, stride length, knee flexion range, and increasing compensatory hip and ankle rotation range.

Maximal knee flexion angle is maintained during midswing phase of gait

Phantom limb pain (PLP) is a common type of chronic pain that occurs after limb amputation. Many treatment approaches are available; however, the treatment of PLP is still a challenge. This study aimed to quantify and rank the efficacy of interventions for phantom limb pain.A comprehensive literature search was performed using the databases of PubMed, MEDLINE, Embase, Web of Science, and Cochrane. A network meta-analysis was applied to formulate direct and indirect comparisons among interventions for PLP.Twenty-two studies comprising 662 patients and 13 different interventions were included in this study. The mirror therapy (MT) (–1.00; 95% confidence interval, –1.94 to –0.07) and MT + phantom exercise (PE) (-6.05; 95% confidence interval, –8.29 to –3.81) group presented significantly lower pain intensity compared with placebo. In SUCRA (surface under the cumulative ranking curve) analysis, the MT+PE and neuromodulation techniques groups had the highest SUCRA value (81.2).Our results suggest that MT is the most optimal treatment for PLP, and a combination of therapies would enhance the therapeutic effect.

Lead knee extension contributes to drag-flick performance in field hockey

ABSTRACTUnderstanding the biomechanics of the drag-flick is important for refining the performance of this task in field hockey. The aim of this study was to determine whether the maximal knee angle and maximal angular velocity of the lead knee extension are associated with ball speed in elite drag-flick players. The kinematics of the drag flick was studied in 19 elite field-hockey players who performed 15 drag-flick shots each towards a target located 1.30 m high at optimal speed. A motion capture suit was used to capture full body drag-flick behaviour sampling at 240 Hz. Multiple regression analyses were used to study the association between both the maximal knee flexion angle and maximal angular velocity of the leading knee extension and ball speed. Significant positive associations were found between knee extension velocity and ball speed (R2 = .127, p < .001). A higher knee extension velocity resulted in higher ball speeds within the individual, without negatively affecting the accuracy. It is advised to train, within an elite drag-flick group, for higher knee extension speed to improve the drag-flick performance. Whether training to improve this parameter results in higher ball speeds should be subject of future studies.

Massage therapy slightly decreased pain intensity after habitual running, but had no effect on fatigue, mood or physical performance: a randomised trial.

Does massage therapy reduce pain and perceived fatigue in the quadriceps, and improve the mood and physical performance of runners after habitual sporting activity (10-km run)? Randomised controlled trial with concealed allocation, intention-to-treat analysis and blinded assessment. Seventy-eight runners after sporting activity (10-km run). The experimental group received 10 minutes of massage to the quadriceps aimed at recovery following sport practice, and the control group received a sham joint mobilisation. Pain and perceived fatigue were each assessed using a 0-to-10 numerical rating scale; pain behaviour via the McGill Pain Questionnaire; mood profile via Brunel Mood Scale; quadriceps muscle flexibility using maximal knee flexion angle via inclinometer; isometric muscle strength of knee extensors via hand-held dynamometry; and vertical jump performance using jump height via My Jump 2 app. Evaluations were carried out immediately before and after the intervention, and at 24, 48 and 72 hours after the intervention. Generalised estimating equations were used to estimate a between-group difference (95% CI) using data across all time points. The experimental group had significantly lower scores than the control group on the numerical rating scale for pain by 0.7 points (95% CI 0.1 to 1.3). There were no significant between-group differences for any of the other outcome measures. Massage therapy was effective at reducing pain intensity after application to the quadriceps of runners compared to a sham technique, but the magnitude of the effect was small. There were no significant effects on perceived fatigue, flexibility, strength or jump performance. Brazilian Registry of Clinical Trials, RBR-393m7m.

Relations between external moment and movement of the knee joint during the stance phase in patients with severe knee osteoarthritis

BackgroundThe relations between external knee moment and the knee joint movement during stance phase of the patients with knee osteoarthritis is unknown well. This study try to clarify the relations between external knee moment and the knee joint movement during stance phase of the patients with knee osteoarthritis. MethodsSubjects comprised 15 patients who had 23 knees with severe osteoarthritis. The knee joint movements and external knee moments while walking were measured using a motion analysis system and a floor-mounted force plate. We then calculated the change in knee joint angles, first and second peak external knee adductions, and maximum flexion−extension moments during the stance phase. Pearson's product−moment correlation coefficient was used to confirm the relation between the external moments and knee movements. ResultsThe first peak external knee adduction moment was moderately positively correlated with the maximum knee varus angle at the early stance phase and was moderately negatively correlated with the amount of change in the knee valgus direction angle at mid-stance. The peak external knee extension moment at the early stance phase was strongly positively correlated with the knee flexion angle at foot-strike and the maximum knee flexion angle at the early stance phase and was negatively correlated with the external rotation angle at foot-strike. ConclusionAn effective rehabilitation approach to decrease the load of knee joint must combine both to strength the muscles around the knee joint, particularly quadriceps, and to device for controlling the knee movement.

Using Machine Learning to Predict Lower-Extremity Injury in US Special Forces.

Musculoskeletal injury rates in military personnel remain unacceptably high. Application of machine learning algorithms could be useful in multivariate models to predict injury in this population. The purpose of this study was to investigate if interaction between individual predictors, using a decision tree model, could be used to develop a population-specific algorithm of lower-extremity injury (LEI) risk. One hundred forty Air Force Special Forces Operators (27.4 ± 5.0 yr, 177.6 ± 5.8 cm, 83.8 ± 8.4 kg) volunteered for this prospective cohort study. Baseline testing included body composition, isokinetic strength, flexibility, aerobic/anaerobic capacity, anaerobic power, and landing biomechanics. To evaluate unilateral landing patterns, subjects jumped off two-feet from a distance (40% of their height) over a hurdle and landing single-legged on a force plate. Medical chart reviews were conducted 365 d postbaseline. χ automatic interaction detection (CHAID) was used, which compares predictor variables to LEI and assigns a population-specific "cut-point" for the most relevant predictors. Twenty-seven percent of operators (n = 38) suffered LEI. A maximum knee flexion angle difference of 25.1% had the highest association with injury in this population (P = 0.006). Operators with >25.1% differences in max knee flexion angle (n = 13) suffered LEI at a 69.2% rate. Seven of the 13 Operators with >25.1% difference in max knee flexion angle weighed >81.8 kg, and 100% of those operators suffered LEI (P = 0.047; n = 7). Only 33% of operators with >25.1% difference in max knee flexion angle that weighed <81.8 kg suffered LEI. This study demonstrated increased risk of LEI over a 365-d period in Operators with greater differences in single-leg landing strategies and higher body mass. The CHAID approach can be a powerful tool to analyze population-specific risk factors for injury, along with how those factors may interact to enhance risk.