Principal components analysis of postural sway in persons with unilateral lower limb amputation: A wearable sensor approach.

Standing sway assessments can detect sensory imbalances which compromise postural control. Persons with lower limb amputation (LLA) often demonstrate impaired postural control, increasing fall risk. Here, principal features of postural sway were identified in persons with unilateral LLA using a single, commercially available wearable sensor.

Ankle sprain bracing solutions and future design consideration for civilian and military use.

Introduction: Ankle sprains are common injuries within the civilian and military populations, with lingering symptoms that include pain, swelling, giving-way, and a high likelihood for recurrence. Numerous bracing systems are available to stabilize the ankle joint following sprains, with new design iterations frequently entering the market. Currently available braces generally include sleeve, lace-up, and stirrup designs.

Low back pain influences trunk-lower limb joint coordination and balance control during standing in persons with lower limb loss.

Background: Balance is sustained through multi-joint coordination in response to postural perturbations. Low back pain alters postural responses; however, it is unknown how coordination between the trunk and lower extremities affects center of mass control during standing balance among persons with limb loss, particularly those with back pain.

Methods: Forty participants with unilateral lower limb loss (23 with back pain) stood with eyes open and closed on a firm surface, while wearing IMUs on the sternum, pelvis, and bilaterally on the thigh, shank, and foot.

Perspectives on Cervical Arthroplasty in Navy and Marine Corps Tactical Jet Aircrew.

Symptomatic cervical spondylosis is a progressive degenerative condition of the cervical spine commonly resulting in functionally-limiting pain, weakness, and/or limited dexterity. Symptomatic cervical spondylosis is believed to occur at higher rates in military aviators than civilian counterparts and is a disqualifying condition for all Navy and Marine Corps aircrew. This condition is non-waiverable for tactical jet (ejection-seat-based) aviators.

Sensitivity of a Subject-specific Ankle Sprain Simulation to Extrinsic Versus Intrinsic Biomechanical Factors.

Ankle sprains are the most common musculoskeletal injury in sport and military activity, despite existing prophylactic strategies. The purpose of this report was to develop a probabilistic simulation of lateral ankle sprains during single-limb drop landing, towards accelerating innovation in ankle sprain prevention. A deterministic, subject-specific musculoskeletal model was extended with automation and probabilistic distributions on sprain-related biomechanical factors.

Lower limb joint-specific contributions to standing postural sway in persons with unilateral lower limb loss.

Background: Individuals with lower limb loss are at an increased risk for falls, likely due to impaired balance control. Standing balance is typically explained by double- or single-inverted pendulum models of the hip and/or ankle, neglecting the knee joint. However, recent work suggests knee joint motion contributes toward stabilizing center-of-mass kinematics during standing balance.

Author Correction: Lower Extremity Joint Contributions to Trunk Control During Walking in Persons with Transtibial Amputation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Lower Extremity Joint Contributions to Trunk Control During Walking in Persons with Transtibial Amputation.

Controlled trunk motion is crucial for balance and stability during walking. Persons with lower extremity amputation often exhibit abnormal trunk motion, yet underlying mechanisms are not well understood nor have optimal clinical interventions been established. The aim of this work was to characterize associations between altered lower extremity joint moments and altered trunk dynamics in persons with unilateral, transtibial amputation (TTA).

Biomechanical improvements following foot strike biofeedback training for a patient using a passive dynamic ankle-foot orthosis during running.

Background And Purpose: Passive dynamic ankle-foot orthoses have potential to facilitate return to running after a lower limb trauma. However, transitioning patients to new movement patterns that enhance passive dynamic ankle-foot orthoses benefits can pose a challenge. The purpose of this case study was to report biomechanical and functional outcomes for a patient utilizing a passive dynamic ankle-foot orthoses following completion of a session-based, midfoot strike run training program.

Do Gait and Functional Parameters Change After Transtibial Amputation Following Attempted Limb Preservation in a Military Population?

Background: Surgical attempts at lower limb preservation after trauma may be complicated by pain and gait disturbances, which can impact the activity level of a military service member. It is unclear how later transtibial amputation (TTA) might affect patients who elect this option after attempts at limb preservation.

Questions/purposes: The purposes of the study were to compare preamputation and postamputation (1) the numeric rating scale for pain and pain medication use; (2) self-reported activity level, Four Square Step Test (FSST) results, and assistive device use; and (3) spatiotemporal variables measured with instrumented gait analysis in individuals who elected TTA after multiple attempts at limb preservation.

Trunk-pelvis motion, joint loads, and muscle forces during walking with a transtibial amputation.

People with unilateral, transtibial amputation (TTA) have an increased prevalence of chronic low back pain (LBP) relative to able-bodied people. However, a definitive cause of increased LBP susceptibility has not been determined. The purpose of this work was to compare dynamic trunk-pelvis biomechanics between people with (n=6) and without (n=6) unilateral TTA during walking using a computational modeling approach.