Sound Limb Research Articles

Persons with Unilateral Transtibial Amputations Modulate Ipsilateral Hip and Contralateral Ankle Joint Work to Accelerate and Decelerate Walking

ABSTRACT Introduction Loss of power production at the ankle joint contributes to many problems people with unilateral transtibial (UTT) amputation experience during walking. Little is known about walking acceleration and deceleration, which is common in daily living and may require substantial compensatory behaviors from the residual lower-limb joints. Objective The aim of this study was to quantify individual lower-limb joint contributions to walking acceleration and deceleration in people with UTT amputations. We hypothesized that joint work on the prosthetic limb would be primarily modulated at the hip, and joint work on the sound limb would be primarily modulated at the ankle. Study Design The study is a repeated-measures design. Methods Six K3 level ambulators with UTT amputations participated. Participants performed a total of 40 walking trials while wearing their own nonarticulated dynamic prosthetic foot and socket. Each trial consisted of walking along a straight walkway. After walking approximately 2 m, participants received a cue instructing them to perform one of three walking conditions: continue walking at a constant average velocity, rapidly accelerate, or rapidly decelerate. We used ground reaction forces and motion capture data to derive joint kinematics and kinetics during the three walking conditions. We used one-way repeated-measures analyses of variance (ANOVAs) to identify significant differences between conditions. Results For the sound limb, positive hip and ankle work was significantly greater during acceleration compared with constant average velocity or deceleration conditions, and negative knee work was significantly greater during acceleration compared with deceleration. For the prosthetic limb, negative ankle work was significantly greater during acceleration compared with deceleration. Conclusions People with UTT amputation who use nonarticulated prostheses primarily modulated joint work on their sound limb to accelerate or decelerate walking speed. Clinical Relevance Characterizing compensatory behaviors of people with a UTT amputation is important for understanding injury mechanisms, informing clinical guidelines, and improving future ankle-foot prosthesis designs.

The Detection of Compensatory Movements in Gait by Evaluating Plantar Pressure in Transfemoral Amputees

Microprocessor-controlled prosthetic knees (MPKs) improve the safety and functional capabilities of transfemoral amputees, but there is a lack of information on plantar pressure distribution and effects among individuals who have undergone transfemoral amputation of the sound limb. (1) Background: The aim of this study was to determine possible compensatory mechanisms in gait by evaluating intact extremity foot plantar pressure distribution in young MPK prosthesis users. Twenty-one patients with unilateral transfemoral amputation (TFA) and twenty-four healthy individuals were selected for the study. (2) Methods: The WalkinSense system was used to assess different foot plantar pressure distribution parameters as the participants walked at their chosen walking speed. Plantar pressure peaks and activation percentages in the eight foot regions were measured during the gait cycle. (3) Results: The pressure peaks and activation percentages in the sound limb with TFA patients and healthy subjects were measured, and statistically significant differences between the two groups were identified. The 1-, 2-, 3-, 4-, and 6-point sensor activation percentages significantly increased, whereas the 7- and 8-point sensor activation percentages decreased in the sound limb TFA participants compared with the healthy subjects. Peak plantar pressure sensor points 1, 3, 4, and 6 increased in the TFA sound limb foot in relation to healthy individuals, while they decreased in point 8. (4) Conclusion: In this study, with the use of a microprocessor knee joint TF prosthesis, in the evaluation of the underfoot pressure of intact legs, the maximum pressure point shifted to the forefoot, and it was observed that the forefoot and midfoot were more active during walking compared with the control group. This may indicate that gait compensation and plantar flexion in the sound limb are used more forcefully in the gait cycle.

Pain, Balance-Confidence, Functional Mobility, and Reach Are Associated With Risk of Recurrent Falls Among Adults With Lower-Limb Amputation

ObjectiveThe study evaluated whether pain intensity and extent, balance-confidence, functional mobility, and balance (eg, functional reach) are potential risk factors for recurrent falls among adults with a lower-limb amputation. DesignCross-sectional study. SettingResearch laboratory. ParticipantsEighty-three adults with unilateral lower-limb amputation that occurred >1 year prior (26 transfemoral- and 57 transtibial-level amputation; 44.6% women; 51.8% traumatic cause of amputation; N=83). InterventionNot applicable. Main Outcome MeasuresParticipants reported on the number of falls in the past year, as well as pain intensity in the low back, residual, and sound limbs. Balance-confidence (per the Activities-Specific Balance-Confidence Scale [ABC]), functional mobility (per the Prosthetic Limb Users Survey of Mobility ([PLUS-M]), and balance (per the Functional Reach and modified Four Square Step Tests) were obtained. ResultsAfter considering non-modifiable covariates, greater extent of pain, less balance-confidence, worse self-reported mobility, and reduced prosthetic-side reach were factors associated with recurrent fall risk. Adults reporting pain in the low back and both lower-limbs had 6.5 times the odds of reporting recurrent falls as compared with peers without pain. A 1-point increase in ABC score or PLUS-M T score, or 1-cm increase in prosthetic-side reaching distance, was associated with a 7.3%, 9.4%, and 7.1% decrease in odds of reporting recurrent falls in the past year, respectively. ConclusionsOf the 83 adults, 36% reported recurrent falls in the past year. Presence of pain in the low back and both lower-limbs, less balance-confidence, worse PLUS-M score, and less prosthetic-side reaching distance were identified as modifiable factors associated with an increased odd of recurrent falls.

An Experimental Approach to Induce Trips in Lower-Limb Amputees.

Reestablishing balance after a trip is challenging for lower-limb amputees and often results in a fall. The effectiveness of reestablishing balance following a trip depends on factors such as amputation level (transtibial or transfemoral) or which limb is tripped (prosthetic or sound/lead or trailing). Understanding the recovery responses can help identify strategies to avoid a trip becoming a fall and what trip-response functionality could be designed into a prosthesis. This study presents an experimental approach for inducing unexpected trips in individuals with amputation. Tripping was manually triggered by activating an electromagnetic device to raisea polypropylene wire to obstruct (bring to a near halt) theswinging limb during its mid-swing phase. A safety harness attached to a ceiling rail ensured participants did not hit the ground if they failed to reestablish balance following the trip (i.e., it prevented a fall from occurring). One transtibial amputee completed repeated walking trials in which a trip was induced around 1 out of 15 times to avoid it being anticipated. 3D kinematics were determined via two smartphones (60Hz) using the OpenCap software, highlighting that the experimental approach induced meaningful tripping/recovery responses dependent on which limb was tripped (prosthetic or sound). The presented methodology avoids using a rigid obstacle, potentially reducing the risk of injuries, and is inexpensive and easy to set up. Importantly it permits a trip to be unexpectedly introduced during the mid-swing phase of the gait and hence provides an approach for identifying real-world trip recovery responses. When tripping the sound limb, participants could 'disentangle' from the trip-wire (post-trip) by plantarflexing the ankle, but such action was not possible when tripping the prosthetic limb.

Evaluation of the hoof centre-of-pressure path in horses affected by chronic osteoarthritic pain.

The Centre of Pressure (COP) is the single point summarising all forces transferred to the hoof during the stance phase of a stride. COP path (COPp) is the trajectory that COP follows from footstrike to lift-off. Aim of the present study was to characterize the COP and COPp in horses affected by osteoarthritis and chronic lameness. Seventeen adult horses with a diagnosis of osteoarthritis and single limb chronic lameness were recruited. The COP was recorded using a wireless pressure measuring system (TekScan®) with sensors taped to the hooves (either fore- or hind limb, depending on lameness location). The COPp coordinates were further processed. Procrustes analysis was performed to assess the variability of single strides COPp and average COPp among strides, gaits, and limbs by calculating Procrustes distances (D-values). A linear mixed-effects model was run to analyse D-values differences for lame and sound limbs. Additionally, average COPp D-values and COPp hoofprint shape indices were compared for lame and sound limbs with the Signed Rank Test. At walk and trot the single-stride COPp D-values were significantly lower in lame than in sound limbs (marginal effects p<0.001). Analysis of the average COPp D-values confirmed that each hoof COPp is highly consistent with itself over subsequent trials but is different from the contralateral. COPp and hoofprint shape indices did not differ between sound and lame limbs. Footstrike and lift-off within the hoofprint showed that most horses had lateral footstrike and lift-off, independently of the lameness location. Our findings are in line with previous observations that COPp are highly repetitive and characteristic for each horse and limb. There seems to be a further decrease in COPp variability in the presence of a painful limb pathology.

A pilot study comparing prosthetic to sound limb gait mechanics during a turning task in people with transtibial amputation

BackgroundObservational gait analysis is frequently used by clinicians to subjectively assess straight walking but is not often used to examine turning. Interlimb comparisons of phase- specific turning biomechanics in people with unilateral lower limb amputation has not previously been documented. MethodsA retrospective examination of gait kinematics and kinetics from five participants with unilateral transtibial amputation was performed. Data were collected during 90° step and spin turns capturing three distinct turning steps. Gait metrics of interest included: total turn time, stance time, peak knee flexion angle during Pre-Swing and Initial Swing gait phases, peak hip flexion and extension, ground reaction impulse, and whole body angular momentum. Statistical comparisons were made based on turn type between sound and prosthetic limbs. FindingsDuring the three turn steps (approach, apex, depart), participants spent significantly more time (P < 0.01) on their sound limb compared to their prosthetic limb regardless of turn type. Additionally, the prosthetic limb hip and knee exhibited more flexion (P < 0.05) during the apex step of turns, and whole body angular momentum was higher when the sound limb was used during the apex step of a turn (P < 0.05). InterpretationThis descriptive study offers the first phase-specific quantification of turning biomechanics in people with lower limb amputation. Results indicate that people with unilateral transtibial amputation spend more time on and experience higher impulses through their sound compared to their prosthetic limb during 90° turns, and that the prosthetic limb is performing differently than the sound limb, potentially increasing risks of injury or falls.

Design Analysis of Prosthetic Unilateral Transtibial Lower Limb with Gait Coordination

People with lower limb amputations struggle through difficulties during locomotion in their daily activities. People with transtibial amputations take support from prosthetic legs for systematic movement. During motion, they experience some mobility issues while using general prosthetic limbs regarding gait pattern. The design of a prosthetic-controlled lower limb with gait synchronization for physically disabled persons is the main goal of the present research work, which can provide an improved walking experience. The design and performance analysis of prosthetic lower limbs for people with transtibial amputations is performed in the present paper. The designed rehabilitation system shows synchronization between the normal and the prosthetic limbs achieved with gait coordination. The dynamics of the lower extremities in different postural activities are used for design purpose utilizing Euler–Lagrange motion theory. The artificial motion of the knee and the ankle joints function through the angular movement of the servo motors according to the movements of the rotary encoders placed on the sound limb joints. The range of motion of both the sound and prosthetic limbs are compared for different steps during a gait cycle. The prosthetic electronic system design of the artificial lower limb is able to show the gait style of human being with body kinesics. The nonlinear domain stability analysis of the designed prosthetic limb is presented through the Lyapunov method. A PIDF2 controller tuning process is implemented for the designed limb’s performance improvement. The designed prosthetic system is beneficial for people with unilateral transtibial amputations with a great societal impact.

Cerebral Hemodynamic Changes during Unaffected Handgrip Exercises in Stroke Patients: An fNIRS Study.

This study aimed to assess the effect of the altered strength of the sound limb on the hemodynamics in the affected brain of stroke patients. We recruited 20 stroke patients to detect changes in the HbO concentrations in the bilateral prefrontal cortex (PFC), sensorimotor cortex (SMC), and occipital lobe (OL). We performed functional near-infrared spectroscopy (fNIRS) to detect changes in oxyhemoglobin (HbO) concentrations in regions of interest (ROIs) in the bilateral cerebral hemispheres of stroke patients while they performed 20%, 50%, and 80% maximal voluntary contraction (MVC) levels of handgrip tasks with the unaffected hands. The results suggest that when patients performed handgrip tasks with 50% of the MVC force, SMC in the affected cerebral hemisphere was strongly activated and the change in the HbO concentration was similar to that of the handgrip with 80% of MVC. When the force was 50% of MVC, the SMC in the affected hemisphere showed a more proportional activation than that at 80% MVC. Overall, this research suggests that stroke patients with a poor upper limb function should perform motor training with their sound hands at 50% of the MVC grip task to activate the ipsilesional hemisphere.

Compensatory relationship of mechanical energy in paretic limb during sit-to-stand motion of stroke survivors

The sit-to-stand motion is a prerequisite for walking and is therefore frequently performed in daily life. Diseases such as stroke often make performing it challenging. Even the stroke survivors who can stand up, the number of sit-to-stand motions they perform each day is lower than that of healthy adults. The inability of stroke survivors to stand up many times might be due to uneven distribution of mechanical energy expenditure across body parts. However, it was unclear in which body part this mechanical energy expenditure was concentrated, i.e., whether it was due to co-contraction of the paretic limb or compensation by the sound limb. Thus, this study aims to identify which body parts are responsible for mechanical energy expenditure in stroke survivors. Ten stroke survivors and ten healthy adults performed sit-to-stand motion recorded using motion capture cameras. We created a 3-D human model and calculated the mechanical energy expenditure for each joint and segment. The stroke survivors expended more mechanical energy in the affected hip and waist in contrast to the affected knee. Notably, a compensatory relationship for mechanical energy expenditure was observed between adjacent joints on the affected side and not between the affected and sound limbs. This is because stroke survivors may have achieved the sit-to-stand motion by compensating for the distal part with the less impaired proximal part. In addition, the more severe the movement disorders, the more mechanical energy must be expended in the paretic hip to achieve the sit-to-stand motion. These results could contribute to fundamental knowledge about more comfortable daily living in stroke survivors.

FUNCTIONAL IMPROVEMENTS MEASURED BY THE CONTINUOUS-SCALE PHYSICAL FUNCTIONAL PERFORMANCE TEST IN A UNILATERAL TRANSFEMORAL AMPUTEE FOLLOWING SOUND SIDE KNEE ARTHROPLASTY: A CASE STUDY

Osteoarthritis is common in the sound limb of persons with a transfemoral amputation (TFA) due to gait abnormalities and increased load on the knee when ambulating with or without aprosthesis. Commonly, a sound-limb total knee arthroplasty (TKA) is required to decrease pain and improve physical function. This case report discusses physical functional outcomes in a person with a TFA following sound limb TKA as measured by the Continuous-Scale Physical Functional Performance Test 10 (CS-PFP 10). A patient with a right TFA underwent a left TKA to improve functional performance. The purpose of this case was to quantify functional changes measured by the CS-PFP 10 at one week pre-TKA and one, three, six, twelve, and eighteen months post-TKA. Skilled standard care physical therapy was immediately implemented post-TKA, which included therapeutic interventions and electrotherapeutic modalities. Additionally, a whole-body high-intensity strengthening program was introduced at eighteen weeks post-operative (post-op) as an adjunct to return the patient to his prior level of function as a CrossFit® athlete.All five CS-PFP 10 domains demonstrated continuous improvement, while the rate of perceived exertion decreased. At one week post-op, the patient’s CS-PFP 10 score indicated an increased likelihood of functional dependence. However, by eighteen months, the patient achieved a total CS-PFP 10 score in the 75 to 90 range, indicating independent function likely. The CS-PFP 10 is a valid instrument to measure improvement in activities of daily living (ADL) in specified functional domains and overall function. Following this patient post-operatively through rehabilitation, the CS-PFP 10 revealed objective improvements demonstrating that sound limb total joint arthroplasty and physical therapy can greatly improve function. These interventions are a viable course of treatment in the presence of contralateral functional impairment in patients with TFA.The CS-PFP 10 is a valid instrument to accurately measure improvements in ADLs in specified functional domains and overall function in the patient population with a TFA followingsound limb TKA.

Symmetry of Body Weight Pressure Distribution on Sound Limb Foot of Unilateral Amputees During Walking

Symmetry of Body Weight Pressure Distribution on Sound Limb Foot of Unilateral Amputees During Walking

Factors leading to falls in transfemoral prosthesis users: a case series of sound-side stumble recovery responses

BackgroundTransfemoral prosthesis users’ high fall rate is related to increased injury risk, medical costs, and fear of falling. Better understanding how stumble conditions (e.g., participant age, prosthesis type, side tripped, and swing phase of perturbation) affect transfemoral prosthesis users could provide insight into response deficiencies and inform fall prevention interventions.MethodsSix unilateral transfemoral prosthesis users experienced obstacle perturbations to their sound limb in early, mid, and late swing phase. Fall outcome, recovery strategy, and kinematics of each response were recorded to characterize (1) recoveries versus falls for transfemoral prosthesis users and (2) prosthesis user recoveries versus healthy adult recoveries.ResultsOut of 26 stumbles, 15 resulted in falls with five of six transfemoral prosthesis users falling at least once. By contrast, in a previously published study of seven healthy adults comprising 214 stumbles using the same experimental apparatus, no participants fell. The two oldest prosthesis users fell after every stumble, stumbles in mid swing resulted in the most falls, and prosthesis type was not related to strategy/fall outcomes. Prosthesis users who recovered used the elevating strategy in early swing, lowering strategy in late swing, and elevating or lowering/delayed lowering with hopping in mid swing, but exhibited increased contralateral (prosthetic-side) thigh abduction and trunk flexion relative to healthy controls. Falls occurred if the tripped (sound) limb did not reach ample thigh/knee flexion to sufficiently clear the obstacle in the elevating step, or if the prosthetic limb did not facilitate a successful step response after the initial sound-side elevating or lowering step. Such responses generally led to smaller step lengths, less anterior foot positioning, and more forward trunk flexion/flexion velocity in the resulting foot-strikes.ConclusionsIntroducing training (e.g., muscle strength or task-specific motor skill) and/or modifying assistive devices (e.g., lower-limb prostheses or exoskeletons) may improve responses for transfemoral prosthesis users. Specifically, training or exoskeleton assistance could help facilitate sufficient thigh/knee flexion for elevating; training or prosthesis assistance could provide support-limb counteracting torques to aid in elevating; and training or prosthesis assistance could help initiate and safely complete prosthetic swing.

Bilateral Change in Vertical Hoof Force Distribution in Horses with Unilateral Forelimb Lameness before and after Successful Diagnostic Anaesthesia.

Simple SummaryLameness is the most common cause of reduced performance in equids. Therefore, its detection, accurate diagnosis, and appropriate treatment are important for animal welfare and economics. Subjective evaluation of a lame horse by visual assessment is prone to error. To objectify the examination, several computer-based systems have been developed. While kinematic investigations focus on the detection of movement asymmetries (e.g., of head, pelvis, withers) with the help of position sensors, kinetic examinations are based on pressure measurement under the hooves. In the current study, horses with unilateral forelimb lameness were equipped with a non-invasive pressure measurement system on both forelimbs simultaneously. Bilateral vertical force distribution (in kg) was evaluated during all phases of stance (landing, midstance, breakover) before and after diagnostic anaesthesia. Vertical force was reduced on the lame limb compared to the sound limb before diagnostic anaesthesia. After positive diagnostic anaesthesia, asymmetries were neutralised: vertical force increased on the lame limb, with breakover being most affected. In conclusion, the current pressure measurement system can be used to objectify lameness examinations in a clinical setting. Both lameness and diagnostic anaesthesia influence the particular phases of stance differently. This might contribute to a better understanding of equine gait and lead to individually optimised shoes.Kinetic examinations of horses with induced lameness as well as the effect of perineural anaesthesia in sound horses have shown promise, but clinical studies regarding the effect of diagnostic anaesthesia during the different stance phases are rare. Fourteen horses with unilateral forelimb lameness were examined with the Hoof™ System during trot to assess vertical force distribution (in kg) affecting both front hooves before and after diagnostic anaesthesia during landing, midstance, and breakover. For statistical analysis, a covariance analysis with repeated measurements regarding the limb (lame/sound) as well as anaesthesia (before/after) and the covariable body weight was performed. The p-values for the pairwise comparisons were adjusted using the Bonferroni–Holm correction (p < 0.05). For all phases of the stance, a significant interaction between the factors limb and anaesthesia was shown. Before diagnostic anaesthesia, vertical force was significantly reduced on the lame limb compared to the sound limb during landing (−25%, p < 0.001), midstance (−20%, p < 0.001) and breakover (−27%, p < 0.001). After anaesthesia, the difference between both forelimbs was not significant anymore for all phases. The vertical force on the lame limb increased significantly after positive anaesthesia during the whole stance phase, with breakover being most affected (+27%, p = 0.001). Pressure measurements with the Hoof™ System can be used to evaluate the effect of diagnostic anaesthesia in a clinical setting with pain-related vertical force asymmetries being neutralised after diagnostic anaesthesia. Breakover is the main event influenced by lameness.

Assessing Ground Reaction Forces and Degenerative Changes of Sound Limb in Unilateral Lower Extremity Amputees: A Systematic Review

Assessing Ground Reaction Forces and Degenerative Changes of Sound Limb in Unilateral Lower Extremity Amputees: A Systematic Review

Impact of a Powered Prosthetic Ankle-Foot Component on Musculoskeletal Pain in Individuals with Transtibial Amputation: A Real-World Cross-Sectional Study with Concurrent and Recalled Pain and Functional Ratings

ABSTRACT Introduction Traditionally, lower-limb prostheses are composed of passive components, which provide a fraction of the push-off power of the natural ankle-foot complex. In individuals with transtibial amputation (TTA), this leads to deviations and compensatory mechanisms. Studies have reported significant unloading of the sound limb and knee joint with a powered prosthetic ankle-foot. However, despite the promising biomechanical evidence on unloading, no study has yet investigated the impact of powered prosthetic ankle-foot on musculoskeletal pain. Methods A total of 250 individuals fit with a powered prosthetic ankle-foot component were invited to participate in an institutional review board–approved cross-sectional study. Participants completed a survey, which collected typical prosthetic history information as well as Numerical Pain Rating Scales across different body regions, the Socket Comfort Score (SCS), the Activity of Daily Living domain of the Knee Injury and Osteoarthritis Outcome Score (KOOS-ADL), and the Oswestry Disability Index (ODI) for both their current and past prosthetic ankle-foot. The differences between results across the two ankle-feet were evaluated in subgroups dependent on the user's current foot. Results A total of 57 individuals met the inclusion criteria after completion of the online survey. Forty-one subjects (71.9%) identified as current powered ankle-foot users. Sixteen subjects (28.1%) reported to have used a powered ankle-foot in the past but have since abandoned it. The current powered ankle-foot users' group saw no significant difference in SCSs. The current passive foot users reported significantly (P = 0.002) better socket comfort for the prosthesis with the passive foot. The original and recall-adjusted median ratings of pain in the group of 41 current powered ankle-foot users showed significantly less pain in all three body segments. In the group of 41 current powered ankle-foot users, both the original and recall-adjusted KOOS-ADL and ODI scores were significantly better for the powered ankle-foot. Conclusions Individuals in active daily life with TTA may experience relief of sound knee, amputated side knee, and low-back pain, as well as pain-related restrictions in activities of daily living function with use of a powered ankle-foot mechanism. Clinical Relevance Providing the right patient with a powered ankle-foot has the potential to decrease the individual's pain. The individual may also have fewer pain-related functional restrictions when attempting to achieve activities of daily living.

Transversal Malalignment and Proximal Involvement Play a Relevant Role in Unilateral Cerebral Palsy Regardless the Subtype.

Classification of gait disorders in cerebral palsy (CP) remains challenging. The Winters, Gage, and Hicks (WGH) is a commonly used classification system for unilateral CP regarding the gait patterns (lower limb kinematics) solely in the sagittal plane. Due to the high number of unclassified patients, this classification system might fail to depict all gait disorders accurately. As the information on trunk/pelvic movements, frontal and transverse planes, and kinetics are disregarded in WGH, 3D instrumented gait analysis (IGA) for further characterization is necessary. The objective of this study was a detailed analysis of patients with unilateral CP using IGA taking all planes/degrees of freedom into account including pelvic and trunk movements. A total of 89 individuals with unilateral CP matched the inclusion criteria and were classified by WGH. Subtype-specific differences were analyzed. The most remarkable findings, in addition to the established WGH subtype-specific deviations, were pelvic obliquity and pelvic retraction in all WGH types. Furthermore, the unclassified individuals showed altered hip rotation moments and pelvic retraction almost throughout the whole gait cycle. Transversal malalignment and proximal involvement are relevant in all individuals with unilateral CP. Further studies should focus on WGH type-specific rotational malalignment assessment (static vs. dynamic, femoral vs. tibial) including therapeutic effects and potential subtype-specific compensation mechanisms and/or tertiary deviations of the sound limb.

Residual limb strength and functional performance measures in individuals with unilateral transtibial amputation

BackgroundIndividuals with lower limb amputation exhibit lower residual limb strength compared to their sound limb. Deficits in residual limb knee flexion and extension strength may impact functional performance during tasks relevant to daily living. Research questionDoes knee flexor and extensor strength in the residual limb impact functional outcome measures, such as walking energetics and performance metrics, in individuals with unilateral transtibial amputation? MethodsFourteen individuals with traumatic unilateral transtibial amputation were recruited for this observational study. Participants completed metabolic testing at three standardized speeds based on leg length, as well maximum isokinetic knee flexion and extension strength for both residual and sound limbs. Participants also completed a series of functional outcome tests, including a two-minute walk test, timed stair ascent test, and four-square step test. Walking energetics (metabolic cost, heart rate, and rating of perceived exertion) and performance metrics were compared to percent deficit of residual limb to sound limb knee flexion and extension muscle strength. A linear regression assessed significant relationships (p < 0.05). ResultsA significant relationship was observed between percent deficit of knee extension strength and heart rate (p = 0.024) at a fast walking speed. Additionally, percent deficit knee flexion strength related to rating of perceived exertion at slow and moderate walking speeds (p = 0.038, p = 0.024). Percent deficit knee extension strength related to two-minute walk time performance (p = 0.035) and percent deficit knee flexion strength related to timed stair ascent time (p = 0.025). SignificanceThese findings suggest the importance of strength retention of the residual limb knee flexion and extension musculature to improve certain functional outcomes in individuals with unilateral transtibial amputation.

Kinetic Analysis in Horses With Deep Digital Flexor Tendinopathy Within the Digit Diagnosed by Magnetic Resonance Imaging

ObjectivesTo determine the stance duration and ground reaction forces (GRF) of horses with deep digital flexor (DDF) tendinopathy at the level of the foot and compare the stance duration and GRF to those of clinically sound horses.DesignProspective clinical study.AnimalsSixteen horses (seven horses with bilateral forelimb lameness, four horses with unilateral forelimb lameness, and five horses with no lameness).ProceduresAnalyses of kinetic variables were performed on both forelimbs from sound horses and horses diagnosed with chronic DDF tendinopathy. Stance duration and longitudinal and vertical components of the GRF were determined for the limbs of clinically sound horses and limbs of horses with DDF tendinopathy. Separate Spearman correlation analyses were used to assess potential association within groups (combined left and right forelimbs of clinically sound horses, lamest limbs of horses with DDF tendinopathy, and contralateral limbs of horses with DDF tendinopathy) and with the set of kinetic variables. Analysis of variance on mean ranks of tied values was used to determine differences in kinetic variables between groups (PROC GLIMMIX) using the kinetic values of the clinically sound horses as the reference group.ResultsThere were a total of 11 lame horses. Seven horses had bilateral forelimb lameness and four had unilateral lameness. Of the 11 horses, there were 15 DDF tendinopathies. There were eight dorsal border DDF tendinopathies, five core DDF tendinopathies, and two sagittal/parasagittal splits DDF tendinopathies. The most lame limbs of horses with DDF tendinopathy had significantly smaller values for peak vertical force and time of peak braking force than did forelimbs of clinically sound horses. Also, the most lame limbs of horses with DDF tendinopathy had significantly larger values for the time of peak vertical force than did forelimbs of clinically sound horses.Conclusions and Clinical RelevanceHorses with chronic DDF tendinopathies develop certain alterations of GRF parameters. This information can be used in future studies to determine if particular kinetic variable changes in horses with DDF tendinopathies differ from those of horses with other pathologies within the foot and therefore could be diagnostic.

GMFCS Level-Specific Differences in Kinematics and Joint Moments of the Involved Side in Unilateral Cerebral Palsy.

A variety of gait pathologies is seen in cerebral palsy. Movement patterns between different levels of functional impairment may differ. The objective of this work was the evaluation of Gross Motor Function Classification System (GMFCS) level-specific movement disorders. A total of 89 individuals with unilateral cerebral palsy and no history of prior treatment were included and classified according to their functional impairment. GMFCS level-specific differences, kinematics and joint moments, exclusively of the involved side, were analyzed for all planes for all lower limb joints, including pelvic and trunk movements. GMFCS level I and level II individuals most relevantly showed equinus/reduced dorsiflexion moments, knee flexion/reduced knee extension moments, reduced hip extension moments with pronounced flexion, internal hip rotation and reduced hip abduction. Anterior pelvic tilt, obliquity and retraction were found. Individuals with GMFCS level II were characterized by an additional pronounced reduction in all extensor moments, pronounced rotational malalignment and reduced hip abduction. The most striking characteristics of GMFCS level II were excessive anterior pelvic/trunk tilt and excessive trunk obliquity. Pronounced reduction in extensor moments and excessive trunk lean are distinguishing features of GMFCS level II. These patients would benefit particularly from surgical treatment restoring pelvic symmetry and improving hip abductor leverage. Future studies exploring GMFCS level-specific compensation of the sound limb and GMFCS level-specific malalignment are of interest.

The effect of prosthetic alignment on the stump temperature and ground reaction forces during gait in transfemoral amputees

BackgroundLower limb prosthetic alignment is a procedure mostly subjective. A prosthetic misaligned induces gait deviations and long-term joint diseases. The alignment effects for each lower limb and the stump stays uncertain. Research objectiveTo identify the effect of the transfemoral alignment prosthesis on ground reaction forces and thermal images of the residual limb. MethodsThe effect of misalignment and nominal alignment was evaluated in sixteen transfemoral amputees. The nominal alignment was considered as the optimal alignment for each subject. Misalignment included random variations in the anterior-posterior and medial-lateral translation of the prosthetic foot and the angle of flexion-extension, abduction-adduction, and internal-external rotation of the socket and prosthetic foot. The control group consisted of fifteen non-amputee individuals. The ground reaction force parameters and stump temperature were analyzed for each alignment condition. The statistical analysis included the one-way ANOVA, Kruskal-Wallis, and multiple comparison tests. ResultsThe prosthesis did not produce statistically significant changes in the average temperature of residual limbs. However, the temperature distribution on the stump skin was different (P < 0.05). The transfemoral prosthesis misalignment produced an irregular heat diffusion on the anterior, posterior, and lateral sides of the stump contour compared to the nominal alignment (P < 0.05). The sound limb did not show differences between nominal alignments and misalignments for most ground reaction force parameters. For almost all GRF parameters, significant differences were observed for the prosthetic limb between misalignment and nominal alignment (P < 0.001). The symmetry indices of ground reaction force parameters of transfemoral amputees did not show any kind of significant improvements after aligning the prosthesis nominally. SignificanceThe stump's temperature distribution and the ground reaction force findings for the prosthetic limb provide a better understanding of the alignment procedure of the transfemoral prosthesis and improve the amputees' compliance to the prosthesis.