Overall Greater Demands on the Musculoskeletal System at Multiple Walking Speeds in Service Members With Lower Limb Loss

Peak tibial axial acceleration during walking is related to intact-side lower limb pain in persons with unilateral transtibial amputation

BACKGROUND

Persons who undergo unilateral transtibial amputation are at an increased risk of secondary musculoskeletal joint pain and degeneration, which has been linked to excessive loading rates of the intact-side limb. Tibial axial acceleration, a feasible measure of loading rates with wearable sensors, would be clinically useful to relate to joint pain in persons with unilateral transtibial amputation.

RESEARCH QUESTION

What is the relationship between peak tibial axial accelerations and intact-side joint pain in persons with unilateral transtibial amputation during walking?

METHODS

Persons with unilateral transtibial amputation (n = 51) were separated into two groups based on the presence of intact-side limb pain (with pain: n = 16; without pain: n = 35). Tibial axial accelerations were measured with bilateral shank-mounted IMUs while participants completed three 10-meter walk tests. Peak tibial axial accelerations for each limb and between-limb symmetry were compared between groups using analysis of co-variance; significance was set at 0.05.

RESULTS

Between persons with vs. without intact-side limb pain, peak tibial axial accelerations were smaller on the prosthetic side (0.64 vs. 0.81 g; p = 0.04), similar on the intact side (0.82 vs. 0.79 g; p = 0.53), and more asymmetrical between sides (intact > prosthetic) (0.81 vs. 1.03 g; p = 0.01).

SIGNIFICANCE

Symmetry in peak tibial axial acceleration can assist with identifying preferential limb loading during walking and, with future research, could serve as a useful clinical target for intact-side limb unloading strategies to help mitigate secondary musculoskeletal pain in persons with unilateral transtibial amputation.

Exploring relationships among multi-disciplinary assessments for knee joint health in service members with traumatic unilateral lower limb loss: a two-year longitudinal investigation

Motivated by the complex and multifactorial etiologies of osteoarthritis, here we use a comprehensive approach evaluating knee joint health after unilateral lower limb loss. Thirty-eight male Service members with traumatic, unilateral lower limb loss (mean age = 38 yr) participated in a prospective, two-year longitudinal study comprehensively evaluating contralateral knee joint health (i.e., clinical imaging, gait biomechanics, physiological biomarkers, and patient-reported outcomes); seventeen subsequently returned for a two-year follow-up visit. For this subset with baseline and follow-up data, outcomes were compared between timepoints, and associations evaluated between values at baseline with two-year changes in tri-compartmental joint space. Upon follow-up, knee joint health worsened, particularly among seven Service members who presented at baseline with no joint degeneration (KL = 0) but returned with evidence of degeneration (KL ≥ 1). Joint space narrowing was associated with greater patellar tilt (r[12] = 0.71, p = 0.01), external knee adduction moment (r[13] = 0.64, p = 0.02), knee adduction moment impulse (r[13] = 0.61, p = 0.03), and CTX-1 concentration (r[11] = 0.83, p = 0.001), as well as lesser KOOSSport and VR-36General Health (r[16] = - 0.69, p = 0.01 and r[16] = - 0.69, p = 0.01, respectively). This longitudinal, multi-disciplinary investigation highlights the importance of a comprehensive approach to evaluate the fast-progressing onset of knee osteoarthritis, particularly among relatively young Service members with lower limb loss.

Lumbopelvic coordination while walking in service members with unilateral lower limb loss: Comparing variabilities derived from vector coding and continuous relative phase

BACKGROUND

Continuous relative phase and vector coding are two common approaches for quantifying lumbopelvic coordination and variability. Evaluating the application of such methodologies to the lower limb loss population is important for better understanding reported asymmetrical movement dynamics of the lumbopelvic region.

RESEARCH QUESTION

How do coordination variabilities derived from trunk-pelvic coupling angles and continuous relative phases compare among individuals with and without unilateral lower limb loss walking at self-selected speeds?

METHODS

Full-body kinematics were obtained from thirty-eight males with unilateral lower limb loss (23 transtibial and 15 transfemoral) and fifteen males without limb loss while walking along a 15 m walkway. Coordination variabilities were derived from trunk-pelvic coupling angles and continuous relative phases and compared using a multivariate approach, as well as in unilateral outcome measures between control participants and participants with lower limb loss.

RESULTS

Overall, tri-planar measures of continuous relative phase variability were 19-43% larger compared to coupling angle variabilities for individuals without limb loss and individuals with transtibial limb loss. Individuals with transfemoral limb loss had 27% and 31% larger sagittal and transverse variabilities from continuous relative phases compared to coupling angles, respectively. During both prosthetic and intact limb stance, individuals with transtibial limb loss had 19-35% greater tri-planar measures of continuous relative phase variability compared to coupling angle variabilities. During intact stance phase, tri-planar measures of continuous relative phase variability were 27%- 42% larger compared to coupling angle variabilities for individuals without limb loss.

SIGNIFICANCE

While both methods provide valid estimates of lumbopelvic movement variability during gait, continuous relative phase variability may provide a more sensitive estimate in the lower limb loss population capturing velocity-specific motions of the trunk and pelvis.