Limb In Gait Research Articles

Avian extremity reconstruction via osseointegrated leg-prosthesis for intuitive embodiment

For large avians such as vultures, limb loss leads to loss of ambulation and eventually death from malnutrition. Prosthetic devices may replace the limb, however, conventional prosthetic sockets are not feasible in feathered limbs and the extreme stress and strain of unreflected daily use in animals. Osseointegration is a novel technique, where external prosthetic parts are connected directly to a bone anchor to provide a solid skeletal-attachment. This concept provides a high degree of embodiment since osseoperception will provide direct intuitive feedback allowing natural use of the limb in gait and feeding. Here we demonstrate for the first time an osseointegrated bionic reconstruction of a limb in a vulture after a tarsometatarsal amputation with a longterm follow-up.

Global Muscle Coactivation of the Sound Limb in Gait of People with Transfemoral and Transtibial Amputation.

The aim of this study was to analyze the effect of the level of amputation and various prosthetic devices on the muscle activation of the sound limb in people with unilateral transfemoral and transtibial amputation. We calculated the global coactivation of 12 muscles using the time-varying multimuscle coactivation function method in 37 subjects with unilateral transfemoral amputation (10, 16, and 11 with mechanical, electronic, and bionic prostheses, respectively), 11 subjects with transtibial amputation, and 22 healthy subjects representing the control group. The results highlighted that people with amputation had a global coactivation temporal profile similar to that of healthy subjects. However, amputation increased the level of the simultaneous activation of many muscles during the loading response and push-off phases of the gait cycle and decreased it in the midstance and swing subphases. This increased coactivation probably plays a role in prosthetic gait asymmetry and energy consumption. Furthermore, people with amputation and wearing electronic prosthesis showed lower global coactivation when compared with people wearing mechanical and bionic prostheses. These findings suggest that the global lower limb coactivation behavior can be a useful tool to analyze the motor control strategies adopted and the ability to adapt to the prosthetic device.

Modular motor control of the sound limb in gait of people with trans-femoral amputation

BackgroundThe above-knee amputation of a lower limb is a severe impairment that affects significantly the ability to walk; considering this, a complex adaptation strategy at the neuromuscular level is needed in order to be able to move safely with a prosthetic knee. In literature, it has been demonstrated that muscle activity during walking can be described via the activation of a small set of muscle synergies. The analysis of the composition and the time activation profiles of such synergies have been found to be a valid tool for the description of the motor control schemes in pathological subjects.MethodsIn this study, we used muscle synergy analysis techniques to characterize the differences in the modular motor control schemes between a population of 14 people with trans-femoral amputation and 12 healthy subjects walking at two different (slow and normal self-selected) speeds. Muscle synergies were extracted from a 12 lower-limb muscles sEMG recording via non-negative matrix factorization. Equivalence of the synergy vectors was quantified by a cross-validation procedure, while differences in terms of time activation coefficients were evaluated through the analysis of the activity in the different gait sub-phases.ResultsFour synergies were able to reconstruct the muscle activity in all subjects. The spatial component of the synergy vectors did not change in all the analysed populations, while differences were present in the activity during the sound limb’s stance phase. Main features of people with trans-femoral amputation’s muscle synergy recruitment are a prolonged activation of the module composed of calf muscles and an additional activity of the hamstrings’ module before and after the prosthetic heel strike.ConclusionsSynergy-based results highlight how, although the complexity and the spatial organization of motor control schemes are the same found in healthy subjects, substantial differences are present in the synergies’ recruitment of people with trans femoral amputation. In particular, the most critical task during the gait cycle is the weight transfer from the sound limb to the prosthetic one. Future studies will integrate these results with the dynamics of movement, aiming to a complete neuro-mechanical characterization of people with trans-femoral amputation’s walking strategies that can be used to improve the rehabilitation therapies.

(v) The hip in cerebral palsy

Summary Deformity and displacement of the hip is the second most common orthopaedic problem to affect children with cerebral palsy. The severity and incidence of hip pathology increases with the severity of cerebral palsy and up to 70% of patients with total body involvement cerebral palsy suffer from hip displacement. Hip deformity can also be problematic in patients who walk as it results in rotational malalignment of the lower limb in gait. Awareness of the problems and appropriate screening permits timely intervention. This may involve management of muscle tone or soft tissue procedures. In more advanced cases of hip displacement and deformity, femoral and pelvic osteotomies are usually required. The goals of treatment range from improving the efficiency of gait to prevention of severe postural problems and pain in the most severely affected.

The Reliability and Validity of Assessment of Sagittal Plane Deviations in Children Who Have Spastic Diplegia

Stott NS, Atherton WG, Mackey AH, Galley IJ, Nicol RO, Walsh SJ. The reliability and validity of assessment of sagittal plane deviations in children who have spastic diplegia. Objective To assess the reliability and validity of a newly described classification of sagittal plane alignment in spastic diplegic gait. Design Twenty split-screen videos of children with spastic diplegia, Gross Motor Function Classification System levels I to III, were viewed on 2 occasions, 6 weeks apart, by 5 raters. The sagittal plane alignments of the right and left lower limbs in gait were classified separately as true equinus, jump knee, apparent equinus, or crouch, based on the published classification. A fifth category, nonclassifiable, was used if classification was not possible. We then used sagittal plane kinematic data to confirm the classification for each subject and these were compared with rater classification scores, which used the video information only. Setting Tertiary-level children’s hospital. Participants Three pediatric orthopedic surgeons and 2 pediatric orthopedic residents. Interventions Not applicable. Main Outcome Measures Gait classification scores derived from visual observation were compared among and within raters. The gait classification scores derived from visual observation were compared with the scores derived from sagittal plane kinematic data to assess validity. Results A moderate correlation was found among the 5 raters within each session, with an interrater weighted κ score of .45 in session 1 and .49 in session 2. The intrarater, weighted κ scores showed a moderate to substantial level of agreement between sessions, ranging from .50 to .68. The classification scores of individual raters had moderate validity when compared with classifications derived from the sagittal plane kinematic data. However, there was a substantial level of agreement between the consensus opinion and the classification obtained using the kinematic data as well as the video recordings (weighted κ=0.8). Conclusions This classification has only moderate reliability and validity when a single experienced rater views the 2-dimensional gait videos. However, the consensus opinion derived from the scores of 5 raters considerably improves the validity of the assessment.