Fitts's Law using lower extremity movement: Performance driven outcomes for degenerative lumbar spinal stenosis.

A paucity of objective outcome measures exists for assessing movement disorders, including degenerative lumbar spinal stenosis (LSS). Fitts's Law provides a novel approach to clinical outcome measurement since performance is resistant to learning, and task difficulty can be altered. The objective of the present study was to compare, using a Fitts's task, movement performance of individuals with and without LSS to determine if motor difficulties that arise with LSS impede the planning, initiation, or execution of deliberate lower limb movements.

The effect of two movement strategies on shoulder resultant joint moment during elastic resistance exercise.

Despite the common use of elastic resistance in training, only the static loading characteristics have been studied, whereas the dynamic components remain undetermined. The purpose was to determine the effect of two movement strategies on the shoulder resultant joint moment (RJM) during internal/external rotation exercise with elastic load. Ten healthy subjects performed sweep and step movement strategies over a constant range of motion and cadence (1:1).

Physical activity intensity and risk of overweight and adiposity in children.

Background: Physical activity recommendations for children focus on duration of activity and underemphasize intensity.

Objective: To evaluate the relationship between physical activity (intensity and duration) and the odds of being overweight, >20% body fat and >25% body fat.

Methods And Procedures: Body fat, BMI and physical activity (accelerometry) were measured in children (n = 251) aged 8-10 years.

The effect of pedometer position and normal gait asymmetry on step count accuracy.

Manufacturers of pedometers recommend wearing a pedometer on the midline of the right thigh and this recommendation is used in research. However, there is conflicting evidence regarding the effect of pedometer position on accuracy. The purpose of this study was to systematically evaluate the effect of pedometer position on accuracy for 3 modes of gait.

Objective assessment of childhood adherence to Canadian physical activity guidelines in relation to body composition.

Low levels of childhood physical activity (PA) are a contributing factor to obesity. The objective of this study was to determine the adherence of children to PA guidelines in relation to body composition. Body fat (Slaughter equation) and body mass index (BMI) were determined during the school year (n = 251, ages 8-11 y).

Contralateral limb strength deficits after anterior cruciate ligament reconstruction using a hamstring tendon graft.

Background: The purpose of this study was to determine whether current post-operative rehabilitation protocols return the strength of the contralateral uninjured limb knee flexors and extensors after an anterior cruciate ligament (ACL) reconstruction to those of an uninjured control group.

Methods: Subjects with a hamstring tendon ACL reconstruction (n=12) were compared to an active control group (n=30). Comprehensive bilateral knee flexor and extensor isovelocity strength testing was performed (five speeds, 5-95 degrees , concentric and eccentric contractions).

Hip strength following hamstring tendon anterior cruciate ligament reconstruction.

Objective: The objective of this study was to determine whether there is alteration in resultant joint moment of the hip extensors and adductors after hamstring anterior cruciate ligament (ACL) reconstruction.

Design: Cross-sectional outcome analysis.

Setting: University sport medicine center.

Hamstring and quadriceps strength balance in normal and hamstring anterior cruciate ligament-reconstructed subjects.

Objective: The purpose of this study was to evaluate and characterize the agonist-antagonist strength balance (hamstring/quadriceps [H/Q] ratio and dynamic control ratio [DCR]) about the knee specific to velocity, range of motion, and contraction type. We hypothesized that there would be systematic variation in the H/Q ratio and DCR based on knee joint angle, angular velocity, and contraction type. We also hypothesized that these ratios would be altered in the anterior cruciate ligament (ACL)-reconstructed group in favor of protecting the ACL graft (relative knee flexor strength when strain on the ACL is the greatest).

The effect of stabilization instruction on lumbar acceleration.

Objective: To determine the effect of trunk stabilization instruction on lumbar acceleration.

Background: There is a paucity of information showing the impact of stabilization training and instruction on lumbar motion. Neuromuscular activation patterns have been implicated as an etiological factor in low back disorders.

Mechanism for activation of locomotor centers in the spinal cord by stimulation of the mesencephalic locomotor region.

The synaptic pathways of mesencephalic locomotor region (MLR)-evoked excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs) recorded from lumbar motoneurons of unanesthetized decerebrate cats during fictive locomotion were analyzed prior to, during, and after cold block of the medial reticular formation (MedRF) or the low thoracic ventral funiculus (VF). As others have shown, electrical stimulation of the MLR typically evoked short-latency excitatory or mixed excitatory/inhibitory PSPs in flexor and extensor motoneurons. The bulbospinal conduction velocities averaged approximately 88 m/s (range: 62-145 m/s) and segmental latencies for EPSPs ranged from 1.