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Gottschalk H.P.,Southwestern Medical Center | Karol L.A.,Texas Scottish Rite Hospital for Children | Jeans K.A.,Movement Science Laboratory
Journal of Pediatric Orthopaedics | Year: 2010

BACKGROUND: Nonoperative methods for clubfoot treatment include the Ponseti technique and French functional method. The purpose of this study was to compare the gait of children presenting with moderate clubfeet who were treated successfully with these techniques. We hypothesized: (1) no difference in gait parameters of moderate clubfeet treated with either of these nonsurgical techniques and (2) gait parameters after treatment for less severe feet would more closely approximate normal gait. METHODS: Patients whose clubfeet were initially scored between 6 and <10 on the Dimeglio scale underwent gait analysis at the age of 2 years. Kinematic evaluation of the ankle was analyzed and kinematic data were classified as abnormal if more than 1 standard deviation from age-matched normal data. Spearman nonparametric correlation coefficients were used to analyze combined data of moderate to very severe clubfeet to determine any relationship between initial severity and gait outcomes. RESULTS: Gait analysis was performed on 33 patients with 40 moderate clubfeet [17 Ponseti, 23 French physical therapy (PT) feet]. Three Ponseti feet were excluded because they had undergone surgery. No statistically significant differences existed in ankle equinus, dorsiflexion, or push-off plantarflexion between the groups. Swing phase foot drop was present in 6 PT feet (26%) compared with zero Ponseti feet (P=0.026). Normal kinematic ankle motion was present more often in the Ponseti group (82%) than PT (48%) (P=0.027). Regardless of treatment, residual intoeing was seen in one-third of children with moderate clubfeet. The combined group of moderate and severe clubfeet showed no correlation between initial Dimeglio score and presence of normal ankle motion or normal gait at 2 years-of-age. CONCLUSIONS: Normal ankle motion was documented more frequently in the Ponseti feet compared with the PT group. Recent implementation of early tendo-achilles release in PT feet may change these outcomes in the future. In conclusion, gait in children with moderate clubfeet is similar to those in patients with severe clubfeet, but the likelihood of surgery may be less. LEVEL OF EVIDENCE: Therapeutic level II. Copyright © 2010 by Lippincott Williams & Wilkins.

Zelik K.E.,University of Michigan | Collins S.H.,Carnegie Mellon University | Adamczyk P.G.,Intelligent Prosthetic Systems, Llc | Segal A.D.,and nter | And 10 more authors.
IEEE Transactions on Neural Systems and Rehabilitation Engineering | Year: 2011

Lower-limb amputees expend more energy to walk than non-amputees and have an elevated risk of secondary disabilities. Insufficient push-off by the prosthetic foot may be a contributing factor. We aimed to systematically study the effect of prosthetic foot mechanics on gait, to gain insight into fundamental prosthetic design principles. We varied a single parameter in isolation, the energy-storing spring in a prototype prosthetic foot, the controlled energy storage and return (CESR) foot, and observed the effect on gait. Subjects walked on the CESR foot with three different springs. We performed parallel studies on amputees and on non-amputees wearing prosthetic simulators. In both groups, spring characteristics similarly affected ankle and body center-of-mass (COM) mechanics and metabolic cost. Softer springs led to greater energy storage, energy return, and prosthetic limb COM push-off work. But metabolic energy expenditure was lowest with a spring of intermediate stiffness, suggesting biomechanical disadvantages to the softest spring despite its greater push-off. Disadvantages of the softest spring may include excessive heel displacements and COM collision losses. We also observed some differences in joint kinetics between amputees and non-amputees walking on the prototype foot. During prosthetic push-off, amputees exhibited reduced energy transfer from the prosthesis to the COM along with increased hip work, perhaps due to greater energy dissipation at the knee. Nevertheless, the results indicate that spring compliance can contribute to push-off, but with biomechanical trade-offs that limit the degree to which greater push-off might improve walking economy. © 2011 IEEE.

Jeans K.A.,Movement Science Laboratory | Karol L.A.,Texas Scottish Rite Hospital for Children | Cummings D.,Prosthetics D.C. | Singhal K.,117 Coronado Drive and 1113
Journal of Bone and Joint Surgery - American Volume | Year: 2014

Results: Kinematic differences of <4 in total prosthetic ankle motion and 8 in external hip rotation were seen between the Syme and transtibial groups. Ankle power was greater in the transtibial group, whereas the Syme group had greater coronal-plane hip power (p < 0.05). Prosthetic ankle motion was significantly greater in the high compared with the medium and low-performance feet. However, the PODCI happiness score was higher in patients with low compared with medium-performance feet (p < 0.05).Conclusions: Small differences in prosthetic ankle motion and power were found between children with Syme and transtibial amputations. Ankle motion was greater in patients using high-performance feet (9% of the total cohort) compared with medium-performance (59%) and low-performance (31%) feet. Despite the increased ankle motion achieved with high-performance dynamic feet, this advantage was not reflected in peak power of the prosthetic ankle or the PODCI sports/physical functioning subscale.Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.Background: Preservation of maximal limb length during amputation is often recommended to maximize the efficiency and symmetry of gait. The goals of this study were to determine (1) whether there are gait differences between children with a Syme (or Boyd) amputation and those with a transtibial-level amputation, and (2) whether the type of prosthetic foot affects gait and PODCI (Pediatric Outcomes Data Collection Instrument) outcomes.Methods: Sixty-four patients (age range, 4.7 to 19.2 years) with unilateral below-the-knee prosthesis use (forty-one in the Syme group and twenty-three in the transtibial group) underwent gait analysis and review of data for the involved limb. The twelve prosthetic foot types were categorized as designed for a high, medium, or low activity level (e.g., Flex foot, dynamic response foot, or SACH). Statistical analyses were conducted. Copyright © 2014 By The Journal of Bone and Joint Surgery, Incorporated.

Morgenroth D.C.,and nter | Morgenroth D.C.,University of Washington | Segal A.D.,and nter | Zelik K.E.,University of Michigan | And 12 more authors.
Gait and Posture | Year: 2011

Lower extremity amputation not only limits mobility, but also increases the risk of knee osteoarthritis of the intact limb. Dynamic walking models of non-amputees suggest that pushing-off from the trailing limb can reduce collision forces on the leading limb. These collision forces may determine the peak knee external adduction moment (EAM), which has been linked to the development of knee OA in the general population. We therefore hypothesized that greater prosthetic push-off would lead to reduced loading and knee EAM of the intact limb in unilateral transtibial amputees.Seven unilateral transtibial amputees were studied during gait under three prosthetic foot conditions that were intended to vary push-off. Prosthetic foot-ankle push-off work, intact limb knee EAM and ground reaction impulses for both limbs during step-to-step transition were measured.Overall, trailing limb prosthetic push-off work was negatively correlated with leading intact limb 1st peak knee EAM (slope = -72 ± .22; p=.011). Prosthetic push-off work and 1st peak intact knee EAM varied significantly with foot type. The prosthetic foot condition with the least push-off demonstrated the largest knee EAM, which was reduced by 26% with the prosthetic foot producing the most push-off. Trailing prosthetic limb push-off impulse was negatively correlated with leading intact limb loading impulse (slope = -34 ± .14; p=.001), which may help explain how prosthetic limb push-off can affect intact limb loading.Prosthetic feet that perform more prosthetic push-off appear to be associated with a reduction in 1st peak intact knee EAM, and their use could potentially reduce the risk and burden of knee osteoarthritis in this population. © 2011 Elsevier B.V.

Tulchin-Francis K.,Movement Science Laboratory | Stevens W.,Movement Science Laboratory | Jeans K.A.,Movement Science Laboratory
Physiological Measurement | Year: 2014

Assessment of physical, ambulatory, activity using accelerometer-based devices has been reported in healthy individuals across a wide range of ages, as well as in multiple patient populations. Many researchers who utilize the StepWatch Activity Monitor (SAM) rely on the default settings for data collection and analysis. A comparison was made between the standard output from the SAM software, and a novel method to evaluate all walking bouts using an Intensity-Duration-Volume (I-D-V) model in healthy children aged 7-13. 105 children without impairment wore the SAM for a total of 1691 d. Statistically significant differences were seen between 7-8-9 year olds and 10-11-12 year olds using the I-D-V model that were not seen using the standard SAM software default output. The increased sensitivity of this technique could be critical for observing the effect of various interventions on patients who experience physical limitations. This new analytical model also allows researchers to monitor activity and exercise-type behavior in a way which coincides with exercise prescription by assessing intensity, duration and volume of activity bouts. © 2014 Institute of Physics and Engineering in Medicine.

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