Juan C. Garbalosa

The effect of orthotics on intersegmental foot kinematics and the EMG activity of select lower leg muscles

BACKGROUND Persons with exertional related leg pain are managed using orthoses. This study aimed to determine the effectiveness of two orthoses in altering foot motion and muscle activity in symptomatic individuals. METHODS 52 subjects with lower extremity pain complaints of a non-traumatic, mechanical origin received one of two orthoses. Foot kinematics and EMG activity were recorded while treadmill walking in 3 footwear conditions. The peak EMG activity of the sandal and sandal orthotic trials (normalized to peak barefoot values) and foot motion during 4 subphases of stance were obtained. Using a multivariate multilevel model via linear mixed models, the effect of orthoses within these phases on motion and EMG was determined. RESULTS An effect of orthotic type was not present for any of the rearfoot or forefoot motions (p>.10). A significant effect of footwear and orthotic type on first ray motion (p<.05) during subphases 2 and 4 was seen. During subphase 4 an interaction effect between footwear condition and orthotic type on tibialis posterior EMG activity (p=.036) was present. CONCLUSION Orthoses are unable to control rear or midfoot motion but appear to control first ray motion and during late stance, affect tibialis posterior muscle activity. Public trials registry number: NCRT02143947.

Lower limb kinematics of male and female soccer players during a self-selected cutting maneuver: Effects of prolonged activity

BACKGROUND Despite the recent emphasis on injury prevention, anterior cruciate ligament (ACL) injury rates remain high. This study aimed to ascertain the effects of prolonged activity on lower limb kinematics during a self-selected cutting maneuver. METHODS Angular kinematics were recorded during an agility test performed until the completion time was greater than the mean plus one SD of baseline trials. Cut type was identified and the hip and knee angles at 33 ms post heel strike were determined. A linear mixed effects model assessed the effects of cut type, gender, and activity status on the hip and knee angles. RESULTS Males performed sidestep cuts more frequently than females. Females increased the incidence of sidestep cuts after prolonged activity. At the hip, a gender-cut type interaction existed for the transverse (p=0.001) and sagittal (p=0.11) planes. Females showed more internal rotation during sidestep and more external rotation and less flexion during crossover cuts. For the frontal plane, a gender-activity status interaction (p = 0.032) was due to no change within females but greater hip adduction during prolonged activity within males. With prolonged activity, both genders displayed less hip (p=0.29) and knee (p=0.009) flexion and more knee (p=0.001) adduction. Females displayed less hip and knee flexion than men (p=0.001). CONCLUSIONS Sidestep may be more risky than crossover cuts. Both genders place themselves in at-risk postures with prolonged activity due to less hip and knee flexion.

Quantification characteristics of digital spiral analysis for understanding the relationship among tremor and clinical measures in persons with multiple sclerosis

BACKGROUND Multiple sclerosis (MS) is a degenerative neurological condition causing demyelination and neuronal loss. Tremor, a symptom of MS, is prevalent in 45.0-46.8% NARCOMS registrants. Although several tools to measure tremor exist, few outcomes are quantitative or regularly utilized clinically. NEW METHOD Introduction of a novel adaptation of the digital spiral drawing to find a quick, sensitive, and clinically useful technique, to predict tremor in persons with MS (pwMS). Digital spiral measures included: Segment Rate (SEGRT), Standard Deviation (SD) of Radial Velocity (VSD-R), SD of Tangential Velocity (VSD-T), SD of Overall Velocity (VSD-O), Mean Drawing Velocity (MNV-O) and Mean Pen Pressure Acceleration (MNA-P). Digital spiral measures were compared with the manual Archimedes Spiral (AS) drawing and the following clinical measures: Finger-Nose Test (FNT), presence of visually observed intention tremor (VOT), Nine-Hole Peg Test (NHPT), and Box and Block Test (BBT). RESULTS All clinical measures utilized demonstrated significant relationships with all digital variables, except VSD-R. The forward-stepwise regression revealed BBT accounted for the most variance, followed by SEGRT. Comparison with Existing Methods: SEGRT is more sensitive in detecting VOT and better for quantifying tremor than AS. BBT and SEGRT are optimal predictive measures for tremor. CONCLUSIONS SEGRT has stronger sensitivity and negative predictive value than AS in detecting VOT. All clinical measures (NHPT, FNT, BBT, and AS) were significantly associated with the digital variables (SEGRT, VSD-T, VSD-O, MNV-O, and MNA-P) except for VSD-R. After controlling for Patient Determined Disease Steps (PDDS), BBT and SEGRT are the best predictive measures for tremor.