The purpose of the study was to determine if the kinematics exhibited by skilled runners wearing a unilateral, transtibial prosthesis during the curve section of a 200-m sprint race were influenced by interaction of limb-type (prosthetic limb (PROS-L) vs. nonprosthetic limb (NONPROS-L)) and curve-side (inside and outside limb relative to the centre of the curve). Step kinematics, toe clearance and knee and hip flexion/extension, hip ab/adduction for one stride of each limb were generated from video of 13 males running the curve during an international 200 m transtibial-classified competition. Using planned comparisons (P < 0.05), limb-type and curve-side interactions showed shortest support time and lowest hip abduction displacement by outside-NONPROS-L; shortest step length and longest time to peak knee flexion by the inside-PROS-L. For limb-type, greater maximum knee flexion angle and lower hip extension angles and displacement during support and toe clearance of PROS-Ls occurred. For curve-side, higher hip abduction angles during non-support were displayed by inside-limbs. Therefore, practitioners should consider that, for curve running, these kinematics are affected mostly by PROS-L limitations, with no clear advantage of having the PROS-L on either side of the curve. 

Appropriate muscular response following an external perturbation is essential inpreventing falls. Transtibial prosthesis users lack a foot-ankle complex and associatedsensorimotor structures on the side with a prosthesis. Its effect on rapid responses ofthe lower-extremity to external surface perturbations is unknown. The aim of thepresent study was to compare electromyographic (EMG) response latencies of otherwisehealthy unilateral transtibial prosthesis users (n=23, mean age 48 years [standarddeviation 14]) and a matched control group (n=23, mean age 48 years [standard deviation13]) following sudden support surface rotations in the pitch plane (toes-up and toesdown).Perturbations were elicited in various weight-bearing and limb-perturbedconditions. The results indicated that transtibial prosthesis users have delayed responsesof multiple muscles of the lower-extremity following perturbation, both in the intact limband the residual limb. Weight-bearing had no influence on the response latency in theresidual limb, but did on the intact limb. Which limb received the perturbation wasfound to influence the muscular response, with the intact limb showing a significantlydelayed response when the perturbation was received only on the side with a prosthesis.These delayed responses may represent an increased risk of falling for individuals thatuse a transtibial prosthesis.

Objective: To investigate the effect of a 10-week training programme on persons with a lower limb amputation and to determine if this training is sufficient to enable running. Subjects: Seven transtibial, 8 transfemoral and 1 bilateral amputee (all resulting from trauma, tumour or congenital) were randomly assigned to a training (n = 8) or control group (n = 8). Methods: Isokinetic hip flexor and extensor strength at 60 and 120 degrees/s and oxygen consumption while walking at 1.0 m/s were tested pre- and post- a 10-week period. The training group followed a twice weekly hip strengthening programme, while the control group continued with their usual activities. Running ability was determined pretesting, and attempted after post-testing for the training group only. Results: The training group increased hip strength and decreased oxygen consumption. Six amputees who were previously unable to run were able to after training. The control group decreased intact limb hip extensor strength. Conclusion: The training programme is sufficient to improve hip strength and enable running in persons with a lower limb amputation. As hip strength was reduced in those not following the training programme, it is recommended that strength training be undertaken regularly in order to avoid losing limb strength following amputation.

The use of vibration as a feedback modality to convey motion of the body has been shown to improve measures of postural stability in some groups of patients. Because individuals using transtibial prostheses lack sensation distal to the amputation, vibratory feedback could possibly be used to improve their postural stability. The current investigation provided transtibial prosthesis users (n = 24, mean age 48 yr) with vibratory feedback proportional to the signal received from force transducers located under the prosthetic foot. Postural stability was evaluated by measuring center of pressure (CoP) movement, limits of stability, and rhythmic weight shift while participants stood on a force platform capable of rotations in the pitch plane (toes up/toes down). The results showed that the vibratory feedback increased the mediolateral displacement amplitude of CoP in standing balance and reduced the response time to rapid voluntary movements of the center of gravity. The results suggest that the use of vibratory feedback in an experimental setting leads to improvements in fast open-loop mechanisms of postural control in transtibial prosthesis users.

Background: Increasing numbers of long jumpers with lower limb amputations choose to take off from their prosthetic limb. It is not yet known what difference in technique, if any, this requires, or which is more advantageous. Objectives: To investigate kinematic differences in long jump technique in athletes with a unilateral transtibial ampution (TT) who take off from their prosthetic limb versus those who take off from their intact limb. Study Design: Naturalistic, field-based, observational; independent group, nonparametric comparison. Methods: Two-dimensional sagittal plane kinematic analysis was performed on all athletes competing in the men's Paralympic TT long jump finals. Five athletes took off from their prosthetic limb (TOprosth) and five from their intact limb (TOintact). Results: No differences were seen between the two groups in terms of jump distance, approach speed or vertical velocity at touch down. While in contact with the take-off board, the two groups gained a similar amount of vertical velocity. However, the TOprosth group appeared to conserve horizontal velocity by using the prosthesis as a 'springboard', minimizing the large hip and knee range of motion displayed by the TOintact group and athletes in previous studies. Conclusions: While differences in technique were observed, no difference was found for jump distance.

ABSTRACT: BACKGROUND: Gait-lines, or the co-ordinates of the progression of the point of application of the vertical ground reaction force, are a commonly reported parameter in most in-sole measuring systems. However, little is known about what is considered a "normal" or "abnormal" gait-line pattern or level of asymmetry. Furthermore, no reference databases on healthy young populations are available for this parameter. Thus the aim of this study is to provide such reference data in order to allow this tool to be better used in gait analysis. METHODS: Vertical ground reaction force data during several continuous gait cycles were collected using a Computer Dyno Graphy in-sole system(R) for 77 healthy young able-bodied subjects. A curve (termed gait-line) was obtained from the co-ordinates of the progression of the point of application of the force. An Asymmetry Coefficient Curve (AsC) was calculated between the mean gait-lines for the left and right foot for each subject. AsC limits of +/- 1.96 and 3 standard deviations (SD) from the mean were then calculated. Gait-line data from 5 individual subjects displaying pathological gait due to disorders relating to the discopathy of the lumbar spine (three with considerable plantarflexor weakness, two with considerable dorsiflexor weakness) were compared to the AsC results from the able-bodied group. RESULTS: The +/- 1.96 SD limit suggested that non-pathological gait falls within 12-16% asymmetry for gait-lines. Those exhibiting pathological gait fell outside both the +/- 1.96 and +/- 3SD limits at several points during stance. The subjects exhibiting considerable plantarflexor weakness all fell outside the +/- 1.96SD limit from 30-50% of foot length to toe-off while those exhibiting considerable dorsiflexor weakness fell outside the +/- 1.96SD limit between initial contact to 25-40% of foot length, and then surpassed the +/- 3SD limit after 55-80% of foot length. CONCLUSION: This analysis of gait-line asymmetry provides a reference database for young, healthy able-bodied subject populations for both further research and clinical gait analysis. This information is used to suggest non-pathological gait-line asymmetry pattern limits, and limits where detailed case analysis is warranted.

An analysis of the take-off technique in transtibial amputee high jump was performed on two athletes (both using intact limb take-off) competing in the high jump finals of the 2004 Paralympic Games. Two digital video cameras were used to film the event with the data later digitized and reconstructed using standard 3D direct linear transformation (DLT) procedures. Some similarities with non-amputee high jump technique were noted in that centre of mass height was low at touch-down (TD), there was a similar magnitude of negative vertical velocity at TD, and most of the vertical velocity generated occurred in the first half of the take-off phase. However, both transtibial amputee athletes exhibited a slower horizontal approach velocity, a lower positive vertical take-off velocity, a more upright position at touch-down and a greater range of motion of the hip throughout the take-off phase compared to what is known about non-amputee high jump technique. These differences may be associated with constraints of taking off from the prosthetic limb on the previous step, resulting in having to adopt a different posture at touch-down compared to non-amputees. Understanding transtibial amputee high jump technique and the differences compared to what is known about non-amputee technique has implications for coaching and improving performance in prosthetic sport.