Does the Powers™ strap influence the lower limb biomechanics during running?

Methodology and Experimental Protocol for Studying Learning and Motor Control in Neuromuscular Structures in Pilates

The benefits of Pilates have been extensively researched for their impact on muscular, psychological, and cardiac health, as well as body composition, among other aspects. This study aims to investigate the influence of the Pilates method on the learning process, motor control, and neuromuscular trunk stabilization, specifically in both experienced and inexperienced practitioners. This semi-randomized controlled trial compares the level of experience among 36 Pilates practitioners in terms of motor control and learning of two Pilates-based skills: standing plank and side crisscross. Data will be collected using various assessment methods, including abdominal wall muscle ultrasound (AWMUS), shear wave elastography (SWE), gaze behavior (GA) assessment, electroencephalography (EEG), and video motion. Significant intra- and inter-individual variations are expected, due to the diverse morphological and psychomotor profiles in the sample. The adoption of both linear and non-linear analyses will provide a comprehensive evaluation of how neuromuscular structures evolve over time and space, offering both quantitative and qualitative insights. Non-linear analysis is expected to reveal higher entropy in the expert group compared to non-experts, signifying greater complexity in their motor control. In terms of stability, experts are likely to exhibit higher Lyapunov exponent values, indicating enhanced stability and coordination, along with lower Hurst exponent values. In elastography, experienced practitioners are expected to display higher transversus abdominis (TrA) muscle elasticity, due to their proficiency. Concerning GA, non-experts are expected to demonstrate more saccades, focus on more Areas of Interest (AOIs), and shorter fixation times, as experts are presumed to have more efficient gaze control. In EEG, we anticipate higher theta wave values in the non-expert group compared to the expert group. These expectations draw from similar studies in elastography and correlated research in eye tracking and EEG. They are consistent with the principles of the Pilates Method and other scientific knowledge in related techniques.

The effect of hip abductor fatigue on knee kinematics and kinetics during normal gait

Objective

To investigate the effect of hip abductor fatigue on the kinematics and kinetics of the knee joint during walking in healthy people to provide a new approach for the prevention and treatment of knee-related injuries and diseases.

Methods

Twenty healthy participants, ten females, and ten males, with a mean age of 25.10 ± 1.2 years, were recruited. Isometric muscle strength testing equipment was used to measure the changes in muscle strength before and after fatigue, and the surface electromyography (SEMG) data during fatigue were recorded synchronously. The Vicon system and an AMTI© force platform were used to record the kinematic parameters and ground reaction force (GRF) of twenty participants walking at a self-selected speed before and after fatigue. Visual 3D software was used to calculate the angles and torques of the hip and knee joints.

Results

After fatigue, the muscle strength, median frequency (MF) and mean frequency (MNF) of participants decreased significantly (P < 0.001). The sagittal plane range of motion (ROM) of the knee (P < 0.0001) and hip joint (P < 0.01) on the fatigue side was significantly smaller than before fatigue. After fatigue, the first and second peaks of the external knee adduction moment (EKAM) in participants were greater than before fatigue (P < 0.0001), and the peak values of the knee abduction moment were also higher than those before fatigue (P < 0.05). On the horizontal plane, there is also a larger peak of internal moment during walking after fatigue (P < 0.01).

Conclusion

Hip abductor fatigue affects knee kinematics and kinetics during normal gait. Therefore, evaluating hip abductor strength and providing intensive training for patients with muscle weakness may be an important part of preventing knee-related injuries.

Immediate effects of hip strap and foot orthoses on self-reported measures and lower limb kinematics during functional tasks in individuals with patellofemoral osteoarthritis: protocol for a randomised crossover clinical trial

Background

Elevated patellofemoral joint stress has been associated with patellofemoral osteoarthritis (PFOA). Changes in lower limb kinematics, such as excessive femoral adduction and internal rotation and excessive rearfoot eversion during the stance phase of functional activities, may increase patellofemoral stress. There is a lack of studies that assess the effects of interventions for controlling femur and subtalar joint movements during functional activities on self-reported measures in individuals with PFOA. Thus, the primary aim of the study is to determine the immediate effects of the hip strap and foot orthoses during level-ground walking and the single-leg squat test on self-reported outcomes. The secondary aim is to investigate whether the hip strap and foot orthoses result in the kinematic changes that these devices are purported to cause.

Methods

Twenty-nine individuals with PFOA aged 50 years or older will take part in the study. The main outcome is pain intensity. The secondary outcomes are other self-reported measures (global rating of change, acceptable state of symptoms, ease of performance, and confidence) and lower limb kinematics (peak femoral adduction and internal rotation, and peak rearfoot eversion). These outcomes will be assessed during functional tasks performed under three conditions: (i) control condition, (ii) hip strap intervention, and (iii) foot orthoses intervention. To investigate whether these interventions result in the lower limb kinematic changes that they are purported to cause, three-dimensional kinematics of the femur and rearfoot will be captured during each task. Linear mixed models with two fixed factors will be used to test associations between the interventions (control, hip strap, and foot orthoses) and conditions (level-ground walking and single-leg squat test) as well as interactions between the interventions and conditions.

Discussion

To the best of the authors’ knowledge, this is the first study to evaluate the immediate effects of the hip strap and foot orthoses on self-reported measures and lower limb kinematics during functional tasks in individuals with PFOA. The findings of this study will enable future trials to investigate the effects of these interventions in rehabilitation programmes.

Trial registration

ClinicalTrials.gov NCT04332900. Registered on 3 April 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06676-0.

The Method of Pose Judgment of Potential Motion Damage in 3D Image Analysis

Objective

This work aimed to study the posture judgment method of 3D image analysis of potential motion damage.

Methods

The motion damage collection was implemented by the 3D image analysis method, and 3D image data were adopted to identify the motion damage data. Moreover, 3D image acquisition technology was adopted to analyze the model of potential motion damage and analyze the simulation judgment result of potential motion damage. Specifically, it included simulation parameters, motion damage posture collection effect, damage detection speed at the collection point, damage accuracy, and damage degree.

Results

(1) The analysis of the damage monitoring speed at multiple collection points of the athletes in the sports environment confirmed that the range of changes in different time periods was different, and the changes showed a fast to slow to fast trend. (2) The 3D image analysis had high accuracy in analyzing the posture of potential motion damage, which rationalized the evolution of injuries. (3) The degree of motion damage under a 3D image changed from rising to gradual, which was in line with the theoretical results (all p < 0.05).

Conclusion

3D image analysis can collect a high degree of small-sample-size data, then perform specific analysis, judgment, and summary, and finally, obtain objective and reasonable data. It greatly reduced the risk of potential motion damage for athletes and also improved the efficiency of injury recognition. Moreover, it reduced the chances of blind prevention and error prevention by athletes, thereby avoiding waste of resources. The simulation test confirmed the advantages of 3D image data collection in the sports environment, and it was solved that the current athletes cannot accurately and timely judge the potential motion damage. It also met the instability needs of the movement personnel of the acquisition system in the changing sports environment and provided a reliable guarantee for the safety and health of the sport personnel.

Influence of the Powers™ strap on pain and lower limb biomechanics in individuals with patellofemoral pain

BACKGROUND

Abnormal biomechanics, especially hip internal rotation and adduction are known to be associated with patellofemoral pain (PFP). The Powers™ strap was designed to decrease hip internal rotation and to thereby stabilise the patellofemoral joint.

OBJECTIVES

This study aimed to investigate whether the Powers™ strap influenced pain and lower limb biomechanics during running and squatting in individuals with PFP.

METHODS

Twenty-four individuals with PFP were recruited using advertisements that were placed at fitness centres. They were asked to perform a single leg squat task (SLS) and to run on an indoor track at their own selected speed during two conditions: with and without the Powers™ strap. Immediate pain was assessed with the numeric pain rating scale. Three-dimensional motion and ground reaction force data were collected with 10 Qualisys cameras and three AMTI force plates.

RESULTS

Immediate pain was significantly reduced with the Powers™ strap (without the Powers™ strap: 4.04 ± 1.91; with the Powers™ strap: 1.93 ± 2.13). The Powers™ strap condition significantly increased hip external rotation by 4.7° during the stance phase in running and by 2.5° during the single leg squat task. Furthermore, the external knee adduction moment during the SLS and running increased significantly.

CONCLUSION

This study assessed the effect of the Powers™ strap on lower limbs kinematics and kinetics in individual with PFP. The results suggest that the Powers™ strap has the potential to improve abnormal hip motion. Furthermore, the Powers™ strap demonstrated an ability to significantly reduce pain during functional tasks in patients with PFP.