The effect of arm restriction on dynamic stability and upper-body responses to lateral loss of balance during walking: an observational study.

When losing balance, upper-body movements serve as mechanical aids to regain stability. However, it remains unclear how these movements contribute to dynamic stability during recovery from a lateral loss of balance while walking with arm restriction. We aimed to (i) quantify the effect of arm restriction on gait stability and upper-body velocities and (ii) characterize upper-body kinematic strategies in response to lateral surface translations under different arm restriction conditions.

Assessing the Knee Extensor's Rate of Force Development Using a Fixed Handheld Dynamometer: An Inter- and Intrasession Reliability Study.

Context: The rate of force development (RFD), defined as the ability to rapidly generate muscle force, is commonly tested using an electromechanical dynamometer in isometric mode. However, these devices are expensive and not readily available. Therefore, this study aims to evaluate the interrater reliability of a fixed handheld dynamometer to measure the knee extensors' RFD and provide reference values using the proposed method.

Elevated proinflammatory cytokines in response to mechanical stimulus are associated with reduced knee loading 2 years after anterior cruciate ligament reconstruction.

Background: The aim of this study was to test the hypothesis that proinflammatory cytokines correlate with knee loading mechanics during gait following a mechanical walking stimulus in subjects 2 years after anterior cruciate ligament reconstruction. Elevated systemic levels of proinflammatory cytokines can be sustained for years after injury. Considering roughly 50% of these patients progress to Osteoarthritis 10-15 years after injury, a better understanding of the role of proinflammatory cytokines such as tumor necrosis factor-α and Interleukin-1β on Osteoarthritis risk is needed.

Translation, cross-cultural adaptation and reliability of the International Knee Documentation Committee (IKDC) subjective knee form and the tampa scale for kinesiophobia (TSK) into Hebrew.

Introduction: The International Knee Documentation Committee-Subjective Form (IKDC-SF) is one of the most used measures for evaluating the quality of life among people experiencing knee pain but is not yet available in Hebrew. Similarly, the Tampa Scale for Kinesiophobia (TSK), used to evaluate fear of movement, is not available in Hebrew. This study aimed to determine the reliability and construct validity of the Hebrew IKDC-SF and TSK among people experiencing chronic knee pain.

Intermittent vibrational stimulation enhances mobility during stair navigation in patients with knee pain.

Background: Reduced quadriceps function and proprioception can cause decreased mobility during stair navigation in patients with knee pain. Patients can benefit from interventions to mitigate pain and restore quadriceps function. Activating the somatosensory system via intermittent vibrational stimulation has the potential to improve stair navigation mobility in patients with knee pain by moderating quadriceps inhibition and enhancing proprioception.

Utilizing the somatosensory system via vibratory stimulation to mitigate knee pain during walking: Randomized clinical trial.

Background: Pain and proprioception deficits are often associated with knee pathologies and resultant quadriceps muscle inhibition. There is a need for new approaches to mitigate active knee pain and restore muscle function during walking. Activating properties of the somatosensory system with common pain and sensory pathways offers a novel opportunity to enhance quadriceps function during walking.

Bridging Disciplines as a pathway to Finding New Solutions for Osteoarthritis a collaborative program presented at the 2019 Orthopaedic Research Society and the Osteoarthritis Research Society International.

Objective: To stimulate future research directions that seek solutions for osteoarthritis (OA) at the interface between diverse disciplines and address osteoarthritis (OA) as a serious disease with a complexity that has presented a barrier to finding safe effective solutions.

Methods: Sessions were conducted at the 2019 meetings of the Orthopaedic Research Society (ORS) and Osteoarthritis Research Society International (OARSI) that included presentations and questions/comments submitted from leading OA researchers representing imaging, mechanics, biomarkers, phenotyping, clinical, epidemiology, inflammation and exercise.

Results: Solutions for OA require a paradigm shift in research and clinical methods in which OA is contextualized as a complex whole-body/person disease.

Changes in stair ascent biomechanics two to eight years after ACL reconstruction are associated with patient-reported outcomes.

Background: Anterior cruciate ligament (ACL) injury is often followed by quadriceps deficits that are apparent with gait analysis. The deficit frequently remains after ACL reconstruction (ACLR). As such, evaluation of ACLR patients could be enhanced by a simple method to detect quadriceps deficits.

Activating the somatosensory system enhances net quadriceps moment during gait.

Quadriceps muscle rehabilitation following knee injury or disease is often hampered by pain, proprioception deficits or instability associated with inhibition of quadriceps activation during walking. The cross-modal plasticity of the somatosensory system with common sensory pathways including pain, pressure and vibration offers a novel opportunity to enhance quadriceps function during walking. This study explores the effectiveness of an active knee brace that used intermittent cutaneous vibration during walking to enhance the peak knee flexion moment (KFM) during early stance phase as a surrogate for net quadriceps moment (balance between knee extensor and flexor muscle moments).

Effect of lateral wedge length on ambulatory knee kinetics.

Background: Lateral wedge insoles (LWI) were proposed to treat medial knee osteoarthritis through reductions of the ambulatory knee adduction moment (KAM). Limited attention was however paid to the LWI length, resulting in unclear understanding of its effect on KAM reductions. The knee flexion moment (KFM) was also shown to be important in knee osteoarthritis, but little is known about the effect of LWI length on it.

The effects of body weight unloading on kinetics and muscle activity of overweight males during Overground walking.

Background: Excess body weight has become a major worldwide health and social epidemic. Training with body weight unloading, is a common method for gait corrections for various neuromuscular impairments. In the present study we assessed the effects of body weight unloading on knee and ankle kinetics and muscle activation of overweight subjects walking overground under various levels of body weight unloading.

Body weight unloading modifications on frontal plane joint moments, impulses and Center of Pressure during overground gait.

Background: Body weight unloading is a common method of gait rehabilitation. However, little is known about its effects on the overground gait biomechanical parameters which were often confounded by the walking modality (treadmill) or the speed variability when subjects walked overground while having to pull the body weight unloading system to which they were attached. By designing a mechanical device that pulled the system at a constant speed, we were able to assess the unique effects of body weight unloading on healthy subjects' kinetics during overground gait.

Effects of body weight unloading on electromyographic activity during overground walking.

Background: Body weight unloading (BWU) on treadmills is a common method of gait rehabilitation. However, treadmills slightly but significantly modify gait biomechanical parameters thus confound the effects of BWU. By conducting our experiments under conditions that replicate daily walking and controlling for speed variability, with a mechanical device designed to pull the BWU system at a constant speed, this study could assess the unique effects of BWU on gait electromyography (EMG) of healthy subjects.

Assessment of the effects of body weight unloading on overground gait biomechanical parameters.

Background: Gait rehabilitation with body weight unloading is a common method of gait rehabilitation for clinical subjects with neurological and musculoskeletal impairments. However, the efficiency of this method was hard to assess given the confounding variables walking modality (treadmill vs. overground) and subjects' inability to maintain a comfortable speed when pulling a body weight unloading system by which they were suspended.