Effects of minute oscillation stretching training on muscle and tendon stiffness and walking capability in people with type 2 diabetes.

Aim: we investigated the effects of a 10 week training program (i.e., minute oscillatory stretching; MOS) on the mechanical responses and walking capability in people with type 2 diabetes (T2D).

Characterization of the vastus lateralis torque-length, and knee extensors torque-velocity and power-velocity relationships in people with Parkinson's disease.

Introduction: Parkinson's disease (PD) is a prevalent neurodegenerative condition observed primarily in the elderly population that gives rise to motor and non-motor symptoms, one of which is muscle weakness. The aim of this study was to characterize the vastus lateralis torque-fascicle length (T-L) and the knee extensors torque-angular velocity (T-V) and power-angular velocity (P-V) relationships in PD patients and to investigate the influence of muscle geometry on muscle mechanics.

Methods: Participants (11 PD: patients, 9 CR: age matched healthy controls; 10 CY: young healthy controls) performed: (i) isometric contractions (e.

Muscle shape changes in Parkinson's disease impair function during rapid contractions.

Aim: Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized, among the others, by muscle weakness. PD patients reach lower values of peak torque during maximal voluntary contractions but also slower rates of torque development (RTD) during explosive contractions. The aim of this study was to better understand how an impairment in structural/mechanical (peripheral) factors could explain the difficulty of PD patients to raise torque rapidly.

The interplay between gastrocnemius medialis force-length and force-velocity potentials, cumulative EMG activity and energy cost at speeds above and below the walk to run transition speed.

New Findings: What is the central question of the study? Are the changes in force potentials (at the muscle level) related with metabolic changes at speeds above and below the walk-to-run transition? What is the main finding and its importance? The force-length and force-velocity potentials of gastrocnemius medialis during human walking decrease as a function of speed; this decrease is associated with an increase in cumulative EMG activity and in the energy cost of locomotion. Switching from fast walking to running is associated to an increase in the force potentials, supporting the idea that the 'metabolic trigger' that determines the transition from walking to running is ultimately driven by a reduction of the muscle's contractile capacity.

Abstract: The aim of this study was to investigate the interplay between the force-length (F-L) and force-velocity (F-V) potentials of gastrocnemius medialis (GM) muscle fascicles, the cumulative muscle activity per distance travelled (CMAPD) of the lower limb muscles (GM, vastus lateralis, biceps femori, tibialis anterior) and net energy cost (C ) during walking and running at speeds above and below the walk-to-run transition speed (walking: 2-8 km h ; running: 6-10 km h ).

Achilles Tendon Mechanical Behavior and Ankle Joint Function at the Walk-to-Run Transition.

Walking at speeds higher than transition speed is associated with a decrease in the plantar-flexor muscle fibres’ ability to produce force and, potentially, to an impaired behaviour of the muscle−tendon unit (MTU) elastic components. This study aimed to investigate the ankle joint functional indexes and the Achilles tendon mechanical behaviour (changes in AT force and power) to better elucidate the mechanical determinants of the walk-to-run transition. Kinematics, kinetic and ultrasound data of the gastrocnemius medialis (GM) were investigated during overground walking and running at speeds ranging from 5−9 km·h−1.

Achilles tendon mechanical properties during walking and running are underestimated when its curvature is not accounted for.

Achilles tendon (AT) mechanical properties can be estimated using an inverse dynamic approach, taking into account the tendon internal moment arm (IMA) and its kinematic behavior. Although AT presents a curvilinear line of action, a straight-line function to estimate IMA and AT length is often utilized in the literature. In this study, we combined kinetic, kinematic and ultrasound data to understand the impact of two different approaches (straight-line vs.

Kinematics of Backward Standing Starts in Elite Cyclists: The Effect of Initial Crank Angle.

In modern sprint cycling competitions, the athletes perform a preparatory movement that consists in reaching the backmost standing position, quickly accelerating the body forward at the starting signal. The purpose of this study was to investigate the kinematics of backward standing starts in elite cyclists, as well as the effect of initial crank angle. Video analysis of cycling starts was performed in seven male elite cyclists during 30 m sprints and in 3 starting conditions: seated with a self-selected crank angle (S-ss), backward standing from a self-selected (BSt-ss) or imposed crank angle of 90° (BSt-90°).

Influence of muscle-belly and tendon gearing on the energy cost of human walking.

This study combines metabolic and kinematic measurements at the whole-body level, with EMG and ultrasound measurements to investigate the influence of muscle-tendon mechanical behavior on the energy cost (C ) of walking (from 2 to 8 km·h ). Belly gearing (Gb = Δmuscle-belly length/Δfascicles length) and tendon gearing (Gt = ∆muscle-tendon unit length/∆muscle-belly length) of vastus lateralis (VL) and gastrocnemius medialis (GM) were calculated based on ultrasound data. Pendular energy recovery (%R) was calculated based on kinematic data, whereas the cumulative activity per distance travelled (CMAPD) was calculated for the VL, GM, tibialis anterior, and biceps femoris as the ratio between their EMG activity and walking speed.

The influence of in vivo mechanical behaviour of the Achilles tendon on the mechanics, energetics and apparent efficiency of bouncing gaits.

In this study, we used kinematic, kinetic, metabolic and ultrasound analysis to investigate the role of elastic energy utilization on the mechanical and physiological demands of a movement task (hopping) that primarily involves the plantar-flexor muscles to determine the contribution of tendon work to total mechanical work and its relationship with apparent efficiency (AE) in bouncing gaits. Metabolic power (PMET) and (positive) mechanical power at the whole-body level (PMEC) were measured during hopping at different frequencies (2, 2.5, 3 and 3.

Anticipatory and pre-planned actions: A comparison between young soccer players and swimmers.

The present study investigated whether a difference exists in reactive and proactive control for sport considered open or closed skills dominated. Sixteen young (11-12 years) athletes (eight soccer players and eight swimmers) were asked to be engaged into two games competitions that required either a reactive and a proactive type of control. By means of kinematic (i.

Postural Adjustments during Interactions with an Active Partner.

Ensuring stability of the human vertical posture is a complex task requiring both anticipatory and compensatory postural strategies when a standing person performs fast actions and interacts with the environment, which can include other persons. How people adjust their preparatory and compensatory postural adjustments in situations when they interact with an active partner is still poorly understood. In this study we investigated the postural adjustments while two healthy persons played a traditional childhood game.

Mechanical advantage and joint function of the lower limb during hopping at different frequencies.

Mechanical output at a joint level could be influenced by its leverage characteristics and by its functional behaviour and both could change to accommodate the demands of a given locomotor task. In this study, the mechanical power generated at the knee and ankle joints and their functional indexes (i.e.

Kinematic and mechanical changes during a long half-marathon race: males and females at uphill/downhill slopes.

Background: The aim of this study was to compare the running kinematics and the spring mass model mechanics over an entire half-marathon race in male and female athletes on different slopes (-7%, 0% and +7%).

Methods: 59 recreational runners (39 males and 20 females) participated in this study. Their running steps at own best self-selected speed were video recorded during a half-marathon (i.

Mechanical determinants of the energy cost of running at the half-marathon pace.

Background: The aim of this study was to determine the influence of spring mass model characteristics (e.g. stiffness) and Achilles tendon properties in determining the energy cost of running in half marathon runners.

Cervical Spine Motion During Vehicle Extrication of Healthy Volunteers.

Prehospital spinal motion restriction as a prevention technique for secondary neurological injury is a key principle in emergency medicine. Our aim was to evaluate the effectiveness of different cervical spinal cord motion restriction techniques of awake and cooperative healthy volunteers during extrication. Twenty-three healthy volunteers were asked to exit a car (unassisted) with a rigid cervical collar (CC condition) or without it (autonomous exit: AE; instructed exit: IE); they were also extricated by two rescuers after setting a rigid cervical collar and by using an extrication device (CC + XT condition).

A kinematic analysis of water ski jumping in male and female elite athletes.

The aim of this study was to perform a kinematic analysis of the in-run, take-off and early flight phases in water ski jumping and to analyse the differences in linear/angular parameters between males and females. Forty-two elite skiers participated in this study (27 males; 15 females); their jumps were video recorded during competitions: the time course of absolute (trunk, thigh, ski) and relative (hip, knee, ankle) angles was calculated, as well as the (trochanter) resultant speed. Males were able to reach faster in-run speeds than females (25.

Mechanical work in shuttle running as a function of speed and distance: Implications for power and efficiency.

Biomechanics (and energetics) of human locomotion are generally studied at constant, linear, speed whereas less is known about running mechanics when velocity changes (because of accelerations, decelerations or changes of direction). The aim of this study was to calculate mechanical work and power and to estimate mechanical efficiency in shuttle runs (as an example of non-steady locomotion) executed at different speeds and over different distances. A motion capture system was utilised to record the movements of the body segments while 20 athletes performed shuttle runs (with a 180° change of direction) at three paces (slow, moderate and maximal) and over four distances (5, 10, 15 and 20 m).

Metabolic and kinematic parameters during walking with poles in Parkinson's disease.

In healthy people, energy expenditure is generally higher during walking with poles (WP) than during conventional walking (W). In persons with Parkinson's disease (PD), walking is slower and may be associated with greater energy consumption, stride-to-stride variability, and difficulty in regulating stride length. The aim of this study was to determine whether treadmill WP at three different speeds could induce changes in gait kinematics and oxygen consumption in PD patients.

Sled Towing: The Optimal Overload for Peak Power Production.

Purpose: The effects of different loads on kinematic and kinetic variables during sled towing were investigated with the aim to identify the optimal overload for this specific sprint training.

Methods: Thirteen male sprinters (100-m personal best: 10.91 ± 0.

Mechanical work and efficiency of 5 + 5 m shuttle running.

Purpose: Acceleration and deceleration phases characterise shuttle running (SR) compared to constant speed running (CR); mechanical work is thus expected to be larger in the former compared to the latter, at the same average speed (v mean). The aim of this study was to measure total mechanical work (W tot (+) , J kg(-1) m(-1)) during SR as the sum of internal (W int (+) ) and external (W ext (+) ) work and to calculate the efficiency of SR.

Methods: Twenty males were requested to perform shuttle runs over a distance of 5 + 5 m at different speeds (slow, moderate and fast) to record kinematic data.

Sprint running: how changes in step frequency affect running mechanics and leg spring behaviour at maximal speed.

The purpose of this study was to investigate the changes in selected biomechanical variables in 80-m maximal sprint runs while imposing changes in step frequency (SF) and to investigate if these adaptations differ based on gender and training level. A total of 40 athletes (10 elite men and 10 women, 10 intermediate men and 10 women) participated in this study; they were requested to perform 5 trials at maximal running speed (RS): at the self-selected frequency (SF) and at SF ±15% and ±30%SF. Contact time (CT) and flight time (FT) as well as step length (SL) decreased with increasing SF, while k increased with it.

A kinematic and metabolic analysis of the first Lu of Tai Chi in experts and beginners.

The aim of this study was to compare movement kinematics, cocontraction times, and metabolic data in expert and nonexpert Tai Chi practitioners. Significant differences were observed for all kinematic parameters: experts moved smoothly (lower jerk) and with a lower frequency. No differences in metabolic and electromyography data were observed but for the breathing pattern (experts breathed slowly and deeply).

Energetics (and kinematics) of short shuttle runs.

Purposes: The energy cost of shuttle running (C netSR), over distances of 10-20 m, was reported to increase with the shuttle speed and to decrease with the shuttle distance. The aims of this study were to assess C netSR over a shorter distance (5 m), at different speeds, and to estimate the energy cost based on a simple kinematic analysis (C netK).

Methods: Ten subjects (six basketball players, BP; four non-basketball players, NBP) performed ten shuttle runs (SR) with 30 s of passive recovery in-between, over a distance of 5 + 5 m (with a 180° change of direction); these experiments were repeated at different speeds (range 2-3.

Does the Pisa syndrome affect postural control, balance, and gait in patients with Parkinson's disease? An observational cross-sectional study.

Introduction: An altered sense of verticality, associated with impaired proprioception and somatosensory integration deficits, has been reported in patients with Parkinson's disease (PD) but it has not been characterized in patients with Pisa syndrome (PS). Therefore, we investigated postural control, balance, and gait disturbances in patients with PD and PS, patients with PD but without PS, and aged-matched normal controls.

Methods: This observational cross-sectional study involved patients with PD and PS (n = 10, Hoehn & Yahr score <4), patients with PD but without PS (n = 10), and age-matched healthy controls (n = 10).

Anatomically asymmetrical runners move more asymmetrically at the same metabolic cost.

We hypothesized that, as occurring in cars, body structural asymmetries could generate asymmetry in the kinematics/dynamics of locomotion, ending up in a higher metabolic cost of transport, i.e. more 'fuel' needed to travel a given distance.