Transhumeral prosthesis use and disuse affects whole-body angular momentum.

Background: Individuals with transhumeral limb loss have an increased risk of falling, potentially resulting from altered upper-body kinematics during gait. The purpose of this study was to investigate whole-body angular momentum as a measure of movement control, to gain an understanding of how these upper-body kinematics contribute to dynamic balance.

Methods: Eight participants with transhumeral limb loss and eight able-bodied control participants completed three gait trials at self-selected speeds.

Transhumeral prosthesis use affects upper body kinematics and kinetics.

Background: Transhumeral (TH) limb loss leads to loss of body mass and reduced shoulder range of motion. Despite most owning a prosthesis, prosthesis abandonment is common. The consequence of TH limb loss and prosthesis use and disuse during gait may be compensation in the upper body, contributing to back pain or injury.

The effect of amplitude normalization technique, walking speed, and reporting metric on whole-body angular momentum and its interpretation during normal gait.

Whole-body angular momentum (WBAM) represents the cancellations of angular momenta that are produced during a reciprocal gait pattern. WBAM is sensitive to small changes and is used to compare dynamic gait patterns under different walking conditions. Study designs and the normalization techniques used to define WBAM vary and make comparisons between studies difficult.

The effect of time to amputation on medical costs accrued during the first twelve months after injury-A California workers' compensation claims study.

Background: This study investigated whether the time to amputation (TtoA) after a work-related injury had a significant effect on the medical costs accrued in the first year after injury.

Data Source: Six thousand nine hundred fifty-three person-level workers' compensation claims data from the state of California, USA, from 2007 to 2018.

Methods: Multiple quantile regression was used to assess the impact of TtoA on medical costs accrued during the first 12 months after injury.

Upper-extremity kinematics and interlimb movement correlation in persons with Parkinson Disease on irregular terrain, cross-slope, and under dual-task condition.

Background: A defining clinical characteristics of Parkinson disease is reduced upper-extremity movements. Irregular terrain, the presence of a cross slope, and dual-task conditions have been found to alter the lower-limb gait characteristics of persons with Parkinson disease but there is little information how different environmental and cognitive conditions impact upper-limb kinematics as well as interlimb movement correlation.

Research Question: Do environmental conditions, such as irregular terrain and the presence of cross slope, as well as dual-task condition impact the upper-extremity kinematics and interlimb movement correlation of persons with Parkinson disease compared to healthy, age-matched controls?

Methods: Three-dimensional whole-body gait data were collected for nine participants with mild-to-moderate Parkinson disease and nine healthy age-matched control participants.

Regulation of whole-body and segmental angular momentum in persons with Parkinson's disease on an irregular surface.

Background: Persons with Parkinson's disease have impaired motor control that increases their chance of falling when walking, especially on difficult terrains. This study investigated how persons with Parkinson's disease regulate their dynamic balance on a regular and an irregular surface.

Methods: Nine participants with Parkinson's disease and nine healthy, age-matched control participants ambulated on both a regular and an irregular surface.

Cervical Muscle Activation Characteristics and Head Kinematics in Males and Females Following Acoustic Warnings and Impulsive Head Forces.

Sex, head and neck posture, and cervical muscle preparation are contributing factors in the severity of head and neck injuries. However, it is unknown how these factors modulate the head kinematics. In this study, twenty-four (16 male and 8 female) participants experienced 50 impulsive forces to their heads with and without an acoustic warning.

The role of neck muscle co-contraction and postural changes in head kinematics after safe head impacts: Investigation of head/neck injury reduction.

Concerns surrounding concussions from impacts to the head necessitate research to generate new knowledge about ways to prevent them and reduce risk. In this paper, we report the relative temporal characteristics of the head resulting from neck muscle co-contraction and postural changes following a sudden force applied to the head in four different directions. In the two "prepared" conditions (i.

Trends in incidence and correlation between medical costs and lost workdays for work-related amputations in the State of California from 2007 to 2018.

Background: Detailed information regarding workers who experience an amputation in the workplace over the last decade is limited. To better understand the financial and functional impact of a work-related amputation, this study quantifies the incidence of work-related amputations in the California workforce from 2007 to 2018 as well as the relationship between medical costs and lost workdays as a function of amputation level.

Methods: Workers' compensation claims data from California spanning the years 2007 to 2018 were evaluated to describe trends in amputation incidence (N = 16 931).

Cervical Muscle Activation Due to an Applied Force in Response to Different Types of Acoustic Warnings.

Mild traumatic brain injury (mTBI) and whiplash-associated disorder are the most common head and neck injuries and result from a sudden head or body acceleration. The head and neck injury potential is correlated with the awareness, level of muscle activation, and posture changes at the time of the perturbation. Environmental acoustic stimuli or a warning system can influence muscle activation and posture during a head perturbation.

Changes in Step Characteristics Over a Known Outdoor Surface Transition: The Effect of Parkinson Disease.

The factors that contribute to the difficulties persons with Parkinson Disease (PwPD) have when negotiating transitions in walking surfaces are not completely known. The authors investigated if PwPD adjusted their step characteristics when negotiating a familiar outdoor surface transition between synthetic concrete and synthetic turf. Force plate and motion capture data were collected for 10 participants with mild to moderate Parkinson disease and 5 healthy older control participants ambulating bidirectionally across the transition between synthetic concrete and synthetic turf.