Improvements in physical functionality in elderly patients with spinal deformity after corrective fusion surgery: a gait analysis

OBJECTIVE Extensive corrective fusion surgery was performed on elderly patients with adult spinal deformity (ASD) to improve abnormal posture. Varying improvements in postoperative walking function were expected owing to differences in muscular strength and bone quality between patients in their 40s and those over 75 years of age. The purpose of this study was to compare preoperative and postoperative gait posture and physical functionality in elderly patients with ASD who underwent extensive corrective fusion to the thoracic spine. METHODS A prospectively maintained surgical database was reviewed for patients with ASD who underwent corrective fusion surgery (thoracic spine to pelvis) between 2011 and 2016. The cohort was divided into three age groups: nonelderly (40–64 years), young-old (65–74 years), and old-old (> 75 years). Patients underwent a 4-m walk test preoperatively and 2 years postoperatively to measure gait-trunk tilt angle and walking speed (meters per minute). RESULTS Among 291 patients with ASD who underwent corrective fusion surgery, 56 patients (14 men and 42 women; mean age 68.8 years) were included. Mean preoperative gait-trunk tilt angle (12.9° vs 5.2°, p < 0.01) and walking speed (41.2 m/min vs 45.7 m/min, p < 0.01) significantly improved postoperatively. Intergroup analysis revealed that the mean preoperative gait-trunk tilt angles in the nonelderly (n = 13), young-old (n = 28), and old-old (n = 15) groups were 11.9°, 10.0°, and 19.3°, respectively; postoperatively, these improved to 4.5°, 4.5°, and 7.2°, respectively. Mean preoperative walking speeds of 47.9, 40.0, and 37.7 m/min improved to 52.4, 44.8, and 41.5 m/min postoperatively in the nonelderly, young-old, and old-old groups, respectively. There were no statistically significant differences in degree of improvement in gait-trunk tilt angle and walking speed among groups. CONCLUSIONS Extensive corrective fusion surgery improved the postoperative walking posture of patients with ASD. Statistical analysis of gait measurements demonstrated intergroup equivalence, indicating comparable improvement in physical functionality in elderly and middle-aged patients after corrective fusion surgery.

Weighted Baseball Training Affects Arm Speed without Increasing Elbow and Shoulder Joint Kinetics

Long-term training effects of weighted ball throwing programs have been well documented. However, the mechanisms by which these effects are facilitated are poorly understood due to the difficulty of measuring biomechanics in the baseball throwing motion. The purpose of this study is to replicate previous methods investigating within-session effects of throwing overload and underload baseballs to provide mechanistic evidence for weighted baseball training methods. We hypothesized that varying the pitched ball weight between three, four, five, six, and seven ounces will affect pitched ball velocity, upper body kinematics, lower body kinematics, kinematic velocities, and throwing arm joint kinetics during a maximum intent throwing workout. Twenty-six collegiate and professional level baseball pitchers ages 20-30 (mean age 23.5 ± 2.7 years) participated in a pitch velocity and biomechanical evaluation while pitching a series of leather weighted baseballs from a regulation pitching mound. A one-way repeated measures ANOVA was used to evaluate the within-subject effect of ball weight on a total of 15 parameters: pitch velocity, five kinematic positions, four kinematic velocities, and five kinetics. We found that as ball weight increased, pitch velocity, maximum elbow flexion, maximum pelvis rotation velocity, maximum shoulder internal rotation velocity, and maximum elbow extension velocity decreased, while anterior trunk tilt at ball release increased. Training with three- to seven-ounce baseballs can be used to work on increasing pitching velocity without increasing throwing arm joint kinetics or changing pitching mechanics in a practically significant way.

Machine learning classifies predictive kinematic features in a mouse model of neurodegeneration

Motor deficits are observed in Alzheimer’s disease (AD) prior to the appearance of cognitive symptoms. To investigate the role of amyloid proteins in gait disturbances, we characterized locomotion in APP-overexpressing transgenic J20 mice. We used three-dimensional motion capture to characterize quadrupedal locomotion on a treadmill in J20 and wild-type mice. Sixteen J20 mice and fifteen wild-type mice were studied at two ages (4- and 13-month). A random forest (RF) classification algorithm discriminated between the genotypes within each age group using a leave-one-out cross-validation. The balanced accuracy of the RF classification was 92.3 ± 5.2% and 93.3 ± 4.5% as well as False Negative Rate (FNR) of 0.0 ± 0.0% and 0.0 ± 0.0% for the 4-month and 13-month groups, respectively. Feature ranking algorithms identified kinematic features that when considered simultaneously, achieved high genotype classification accuracy. The identified features demonstrated an age-specific kinematic profile of the impact of APP-overexpression. Trunk tilt and unstable hip movement patterns were important in classifying the 4-month J20 mice, whereas patterns of shoulder and iliac crest movement were critical for classifying 13-month J20 mice. Examining multiple kinematic features of gait simultaneously could also be developed to classify motor disorders in humans.

The Effects of Contralateral Trunk Tilt on Elbow Varus Torque in Baseball Pitchers: A Critically Appraised Topic

Clinical Scenario: Ulnar collateral ligament injuries are common in baseball pitchers, with excessive elbow varus torque linked to medial elbow injuries. Trunk tilt, or motion in the frontal plane, could be an identifiable and modifiable factor in medial elbow loading. Clinical Question: In high school through professional baseball pitchers, how does increased contralateral trunk tilt compared with no/limited contralateral trunk tilt influence elbow varus torque? Summary of Key Findings: Four studies were included: all were labeled as “controlled” or “descriptive laboratory studies,” representing cross-sectional observational analytic design. One study compared biomechanics of professional pitchers with and without ulnar collateral ligament reconstruction. Two studies measured biomechanics in college pitchers, one of which also included simulations of joint angles. The fourth study measured biomechanics of high school pitchers. All studies measured trunk tilt and its relationship to elbow varus torque, with 3 of the studies linking increased contralateral trunk tilt with increased elbow varus torque. Clinical Bottom Line: Moderate evidence indicated as contralateral trunk tilt increased, so did elbow varus torque, indicating trunk tilt may be a modifiable factor to decrease medial elbow loading during pitching. Strength of Recommendation: Majority consistent findings from the level 3 cross-sectional observational analytic designs suggest grade B evidence in support of trunk tilt as a factor in increasing elbow varus torque.

Total knee arthroplasty for patients with medial knee osteoarthritis improves trunk movement during gait

BACKGROUND: Previous studies have indicated that the kinematics of the knee joint affect the trunk and pelvis during gait. However, the factors that influence trunk movement in knee osteoarthritis patients during gait after surgery remain unclear. OBJECTIVE: To examine the effect of total knee arthroplasty (TKA) on trunk movement during gait by comparing knee osteoarthritis patients with healthy controls. METHODS: Fourteen medial knee osteoarthritis patients who underwent initial unilateral TKA and 11 controls participated in this study. Knee and hip joint flexion and trunk and pelvic tilts during gait were acquired using a three-dimensional motion analysis system. Knee joint range of motion, pain, and kinematic data were collected preoperatively and 1 year postoperatively for knee osteoarthritis patients. RESULTS: Knee extension limitation and pain significantly improved postoperatively compared with preoperative stages. Preoperatively, the peak anterior trunk tilt during the stance phase was significantly larger in osteoarthritis patients than in controls. The peak anterior trunk tilt during the stance phase was significantly smaller postoperatively than at preoperative stages. CONCLUSIONS: These results suggest that after TKA, the trunk movements of knee osteoarthritis patients were approximately equal to those of controls, with improvement in clinical outcomes such as knee extension limitation and pain.

Biomechanical Analysis of an Overhead Baseball Throwing Movement Associated with a Cardiorespiratory Fatigue Effect

Background: Overhand pitching is a movement that requires the coordination of lower extremity, trunk, and upper extremity segments to effectively transfer force throughout the kinetic chain to project a baseball. Objective: The purpose of this study was to investigate the effect of cardiorespiratory fatigue on throwing ball velocity related to kinematics motion changes in baseball. Methods: The study samples included 12 male baseball athletes (19.3 ± 2.8 years old, height of 1.71.4 ± 3.1 m, and weight of 64.3 ± 3.6 kg). A descriptive quantitative method approach was used. The instruments included two high-resolution handycams (Sony HXR-MC2500, Japan), a high-speed camera (Fastec Imaging TS5-H, USA), a radar speed gun (Bushnell 101922, Germany), a 3D force platform (The AMTI Optima Series 20210, USA), 14 point manual markers, a motion capture system software (Frame DIAZ IV, Japan), and a heart rate sensor (Polar H10, Finland). Results: The results of this study showed that there were significant differences in the ball velocity (p= 0.042), stride length percentage height (p= 0.041), elbow flexion (p= 0.046), maximum shoulder horizontal adduction (p= 0.041), maximum elbow extension angular velocity (p= 0.035), maximum shoulder internal rotation (p= 0.029), and lateral trunk tilt (p= 0.029) when the pitchers were fatigued. Conclusion: Cardiorespiratory fatigue causes changes in the kinetic harmonization of upper and lower body motion, which results in a decrease in the ball velocity. These results are similar to those in previous studies conducted with the intervention of muscle fatigue during overhead baseball throwing, which causes a decrease in the performance and ball velocity.

Hammer Throw: A Pilot Study for a Novel Digital-Route for Diagnosing and Improving Its Throw Quality

The world record of the hammer throw has not been broken since 1986. This stagnation is multifactorial. One dominant factor could be the lack of evidence-based scientific/biofeedback training. This study aims to identify key parameters influencing throw quality and structure a new digital method for biofeedback training. Wire-tension measurement and 3D motion capture technology (VICON 12-camera system) were applied in quantifying and comparing throws of a national-level and a college-level athlete. Our results reveal that multi-joint coordination influences heavily on wire-tension generation. Four phases, i.e., initiation, transition, turns, and throw, play various roles in evaluating the quality of a throw. Among them, the transition, the third turn, and the throw display explosive/rapid increases of tension. For improving the effectiveness of the skill, the whip-like control and proper SSC (stretch-shortening cycle) of muscle groups involved should be established through years of training. Furthermore, our study unveils that quick and complex full-body control could be quantified and characterized by four key parameters: wire-tension, hand- and hip-height, and trunk tilt. Hence, a wearable digital device with tension and three Inertial Measurement Unit (IMU) sensors would have great potential in realizing real-time biomechanical feedback training in practice for evaluating and improving the efficiency of various training programs.

Individual factors associated with baseball pitching performance: scoping review

BackgroundBall velocity, accuracy and game statistics represent three methods used to measure pitching performance. However, individual determinants of pitching performance are more elusive.ObjectivesThe aims of this study were to classify the performance factors associated with baseball pitchers, to identify the methods used to quantify their abilities through all features of the game and to document relationships between performance factors and indicators.DesignScoping review.Data sourcesElectronic searches of MEDLINE, Academic Search Complete, CINAHL, SportDiscus, PubMed, PsycINFO, Cochrane and of grey literature were undertaken from inception to January 2019.Eligibility criteria for selecting studiesCross-sectional studies that investigated the relationship between performance indicators and individual performance factors in healthy baseball pitchers were selected.ResultsThirty-four cross-sectional studies investigating individual potential factors of pitching performance met the inclusion criteria. The primary performance factors investigated were kinematic, kinetic, timing outcomes, personal characteristics, physical tests and range of motion. Shoulder horizontal adduction (SHA), upper torso forward flexion, maximal shoulder external rotation, upper torso rotation angle, upper torso lateral flexion, lead knee flexion (LKF) and forward trunk tilt (FTT) were identified as key kinematic features associated with increased ball velocity. Shoulder proximal force and peak elbow proximal forces were associated with greater ball velocity. Individual performances in jumping tests and body weight (BW) are also associated with pitching performance.Summary/conclusionBased on studies presenting low and moderate risk of bias, we conclude that BW, age and kinematics, such as FTT, LKF, SHA and lateral trunk tilt, are associated with pitching performance.