Adductor moment

As animals increase in size, common patterns of morphological and physiological scaling may require them to perform behaviors such as locomotion while experiencing a reduced capacity to generate muscle force and an increased risk of tissue failure. Large mammals are known to manage increased mechanical demands by using more upright limb posture. However, the presence of such size-dependent changes in limb posture has rarely been tested in animals that use non-parasagittal limb kinematics. Here, we used juvenile to subadult American alligators (total length 0...

This study aimed to analyze the variations of fitness status, as well as test the relationships between accumulated training load and fitness changes in women soccer players. This study followed an observational analytic cohort design. Observations were conducted over 23 consecutive weeks (from the preseason to the midseason). Twenty-two women soccer players from the same first Portuguese league team (22.7 ± 5.21 years old) took part in the study. The fitness assessment included anthropometry, hip adductor and abductor strength, vertical jump, change of direction, linear speed, repeated sprint ability, and the Yo-Yo intermittent recovery test...

BACKGROUND: To elucidate the formation process and therapeutic targets of hip flexion contracture, we developed a rat model of hip flexion contracture induced by hip mono-articular immobilization. METHODS: Kirschner wires inserted into the femur and hip bone were anchored at the hip in a flexed position in the immobilization groups and unanchored in the sham groups for up to four weeks. Age-matched untreated rats were used as controls. Hip extension range of motion (RoM) was measured at three different extension moments (7...

Standing yoga poses strengthen a person's legs and helps to achieve the goal of musculoskeletal rehabilitation, but inadequate exercise planning can cause injuries. This study investigated changes in the electromyogram and joint moments of force (JMOFs) of lower extremities during common standing yoga poses in order to explore the feasibility and possible injury risk in dealing with musculoskeletal problems. Eleven yoga instructors were recruited to execute five yoga poses (Chair, Tree, Warrior 1, 2, and 3)...

This study was aimed at exploring the biomechanical characteristics of the lower extremity amongst three typical yoga manoeuvres. A total of thirteen experienced female yoga practitioners were recruited in the current study; they were all certified with the Yoga Alliance. A three-dimensional motion capture system with 10 cameras combined with four synchronised force plates was used to collect kinematics of the lower extremity and ground reactive force whilst the participants performed the crescent lunge pose, warrior II pose, and triangle pose...

The golf swing has been associated with mechanical injury risk factors at many joints. One swing, the Minimalist Golf Swing, was hypothesised to reduce lumbar spine, lead hip, and lead knee ranges of motion and peak net joint moments, while affecting swing performance, compared to golfers' existing swings. Existing and MGS swings of 15 golfers with handicaps ranging from +2 to -20 were compared. During MGS downswing, golfers had 18.3% less lumbar spine transverse plane ROM, 40.7 and 41.8% less lead hip sagittal and frontal plane ROM, and 39...

Background and Objectives : Acquiring knowledge about the magnitude and direction of induced joint forces during modifying gait strategies is critical for proper exercise prescription. The present study aimed to evaluate whether a heel-first strike pattern during gait can affect the biomechanical characteristics of ankle and knee joints among asymptomatic people. Materials and Methods : In this cross-sectional study performed in the biomechanics laboratory, 13 professional healthy male athletes walked on an instrumented walkway under two walking conditions...

BACKGROUND: Dry needling (DN) is often used for the treatment of muscle pain among physiotherapists. However, little is known about the mechanisms of action by which its effects are generated. The aim of this randomized controlled trial was to determine if the use of DN in healthy subjects activates the sympathetic nervous system, thus resulting in a decrease in pain caused by stress. METHODS: Sixty-five healthy volunteer subjects were recruited from the University of Alcala, Madrid, Spain, with an age of 27...

BACKGROUND: Bounce rope-skip holds immense scope as an aerobic exercise in space and time constrained urban setting with additional constraints placed by pandemic situations such as Covid 19, wherein adherence to commonly performed weight-bearing, aerobic activities like walking and running is a challenge. Limited knowledge informing biomechanical demands and misconceptions about knee joint loading, confines safe application of bounce rope-skip in health promotion. Thus, present study aimed to explore kinematics and lower-extremity joint loading during rope-skipping compared to walking and running...

Objective: Femoral offset (FO) restoration is significantly correlated with functional recovery following total hip arthroplasty (THA). Accurately assessing the effects of FO changes on hip muscles following THA would help improve function and optimize functional outcomes. The present study aimed to (1) identify the impact of FO side difference on the hip muscle moment arms following unilateral THA during gait and (2) propose the optimal FO for a physiological hip muscle function. Methods: In vivo hip kinematics from eighteen unilateral THA patients during gait were measured with a dual-fluoroscopic imaging system...

We developed a three-dimensional, computational biomechanical model of a juvenile Nile crocodile (Crocodylus niloticus) pelvis and hindlimb, composed of 47 pelvic limb muscles, to investigate muscle function. We tested whether crocodiles, which are known to use a variety of limb postures during movement, use limb orientations (joint angles) that optimise the moment arms (leverages) or moment-generating capacities of their muscles during different limb postures ranging from a high walk to a sprawling motion...

Mausehund, L, Werkhausen, A, Bartsch, J, and Krosshaug, T. Understanding bench press biomechanics-The necessity of measuring lateral barbell forces. J Strength Cond Res XX(X): 000-000, 2020-The purpose of this study was to advance the expertise of the bench press exercise by complementing electromyographic (EMG) with net joint moment (NJM) and strength normalized NJM (nNJM) measurements, thus establishing the magnitude of the elbow and shoulder muscular loads and efforts. Normalized NJMs were determined as the ratio of the bench press NJMs to the maximum NJMs produced during maximum voluntary isokinetic contractions...

The moment arm of a muscle's force represents the muscle's leverage or mechanical advantage in producing a joint moment. It is indicative of the muscle's potential to contribute to actuation of a joint in a particular joint motion direction and defines the role of the muscle, for example, as a joint flexor or abductor. The aims of this study were, firstly, to measure the moment arms of the flexor and extensor muscles of the metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints, and the moment arms of the major abductor and adductor muscles of the metacarpophalangeal (MCP) joint of each finger in the hand; secondly, to assess the effect of change in joint angle on these moment arms; and thirdly, to determine if there are differences in a given flexor or extensor's muscle moment arms between the joints it spans on a given finger, and across its tendon slips to multiple fingers...

Few studies have assessed knee range of motion (ROM) and moments of patients with mobile-bearing unicompartmental knee arthroplasty (MB UKA) during active deep flexion activities. We analyze knee kinematic and kinetic parameters during postoperative squatting-standing activity, aiming to evaluate the efficacy of MB UKA and postoperative rehabilitation progress. This was a clinical cohort study. We followed up with 37 patients diagnosed with medial knee osteoarthritis (OA) with primary UKA. After screening 31 patients were recruited to take gait tests...

Electromyography (EMG)-driven musculoskeletal modeling relies on high-quality measurements of muscle electrical activity to estimate muscle forces. However, a critical challenge for practical deployment of this approach is missing EMG data from muscles that contribute substantially to joint moments. This situation may arise due to either the inability to measure deep muscles with surface electrodes or the lack of a sufficient number of EMG channels. Muscle synergy analysis (MSA) is a dimensionality reduction approach that decomposes a large number of muscle excitations into a small number of time-varying synergy excitations along with time-invariant synergy weights that define the contribution of each synergy excitation to all muscle excitations...

Step-by-step foot placement control, relative to the center of mass (CoM) kinematic state, is generally considered a dominant mechanism for maintenance of gait stability. By adequate (mediolateral) positioning of the center of pressure with respect to the CoM, the ground reaction force generates a moment that prevents falling. In healthy individuals, foot placement is complemented mainly by ankle moment control ensuring stability. To evaluate possible compensatory relationships between step-by-step foot placement and complementary ankle moments, we investigated the degree of (active) foot placement control during steady-state walking, and under either foot placement-, or ankle moment constraints...

OBJECTIVE: Externally applied abduction and rotational loads are major contributors to the knee joint injury mechanism; yet, how muscles work together to stabilize the knee against these loads remains unclear. Our study sought to evaluate lower limb functional muscle synergies in healthy young adults such that muscle activation can be directly related to internal knee joint moments. METHODS: Concatenated non-negative matrix factorization extracted muscle and moment synergies of 22 participants from electromyographic signals and joint moments elicited during a weight-bearing force matching protocol...

BACKGROUND: Children with cerebral palsy (CP) present with a pathological gait pattern due to musculoskeletal impairments, such as muscle weakness and altered bony geometry. However, the effect of these impairments on gait performance is still unknown. Research aim:This study aimed to explore the effect of hip muscle weakness and femoral deformities on the gait performance of CP and typical developing (TD) subjects. METHODS: 6400 musculoskeletal models were created by weakening the hip extensors, abductors, adductors and flexors from 0% to 75 % and increasing the femoral anteversion angle (FAA) and neck shaft angle (NSA) from 20° to 60° and 120° to 160°, respectively...

CONTEXT: Previous authors have shown associations between kinematics on the single-legged step down (SLSD) and running mechanics. Therefore, the SLSD may be a useful tool for identifying runners with poor running mechanics when 2- or 3-dimensional gait analysis is not available. However, the associations between SLSD performance and running kinetics, as well as the influences of sex and muscle strength on these relationships, remain unclear. OBJECTIVE: To evaluate whether kinematics on the SLSD predict kinematics and kinetics while running and whether the relationships differ between men and women and are mediated by muscle strength...

BACKGROUND: The purpose of this study was to compare muscle forces and hip contact forces (HCFs) during squatting in patients with cam-type femoroacetabular impingement (cam-FAI) before and after hip corrective surgery and with healthy control participants. METHODS: Ten symptomatic male patients with cam-FAI performed deep squatting preoperatively and at 2 years postoperatively. Patients were matched by age and body mass index to 10 male control participants. Full-body kinematics and kinetics were computed, and muscle forces and HCFs were estimated using a musculoskeletal model and static optimization...