BIOENERGETIC DIFFERENCES DURING WALKING AND RUNNING IN TRANSFEMORAL AMPUTEE RUNNERS USING ARTICULATING AND NON-ARTICULATING KNEE PROSTHESES

Sprinting performance of individuals with unilateral transfemoral amputation: compensation strategies for lower limb coordination

Understanding the sprinting patterns of individuals with unilateral transfemoral amputation (uTFA) is important for designing improved running-specific prostheses and for prosthetic gait rehabilitation. Continuous relative phase (CRP) analysis acquires clues from movement kinematics and obtains insights into the sprinting coordination of individuals with uTFA. Seven individuals with uTFA sprinted on a 40 m runway. The spatio-temporal parameters, joint and segment angles of the lower limbs were obtained, and CRP analysis was performed on thigh-shank and shank-foot couplings. Subsequently, the asymmetry ratios of the parameters were calculated. Statistical analyses were performed between the lower limbs. Significant differences in the stance time, stance phase percentage, ankle joint angles and CRP of the shank-foot coupling (p < 0.05) were observed between the lower limbs. The primary contributor to these differences could be the structural differences between the lower limbs. Despite the presence of different coordination features in the stance and swing phases between the lower limbs, no significant difference in the coordination patterns of the thigh-shank coupling was observed. This may be a compensation strategy for achieving coordination patterns with improved symmetry between the lower limbs. The results of this study provide novel insights into the sprinting movement patterns of individuals with uTFA.

Development and Evaluation of a Passive Mechanism for a Transfemoral Prosthetic Knee That Prevents Falls during Running Stance

Existing prosthetic knees used by transfemoral amputees have function almost akin to non-friction hinge joints during the running stance phase. Therefore, transfemoral amputees who wish to run need sufficient strength in their hip extension muscles and appropriate prosthetic leg swing motion to avoid falling due to unintended prosthetic knee flexion. This requires much training and practice. The present study aimed to develop a passive mechanism for a transfemoral prosthetic knee to prevent unintended prosthetic knee flexion during the running stance phase. The proposed mechanism restricts only flexion during the prosthetic stance phase with a load on the prosthetic knee regardless of the joint angle of the prosthetic knee. The load on the prosthetic knee required to maintain locked flexion was analyzed. We developed a rough prototype and conducted an evaluation experiment with an intact participant attached to a simulated prosthetic limb and the prototype. The results of level walking showed that the proposed mechanism limits knee flexion, as designed. The results of the preliminary trial suggest that the proposed mechanism functions appropriately during running, where the load on the prosthetic knee is larger than that during walking.

Strategies for Gait Retraining in a Collegiate Runner with Transfemoral Amputation: A Case Report

BACKGROUND

More than fifty percent of people with limb amputations participate in sports or physical activity following amputation. Athletes with limb amputations may face additional challenges including phantom limb pain (PLP), psychological barriers, prosthetic complications, and gait abnormalities. Prevalence of PLP in the general amputee population is estimated to be as high as 85%. Despite the high prevalence of PLP, there is little research regarding the use of gait training as a treatment for PLP among both the general amputee population and athletes.

CASE DESCRIPTION

A 20-year old female collegiate track and field athlete presented with phantom knee pain brought on with running. The athlete demonstrated deficits in core and hip strength as well as decreased single leg stability bilaterally. Running gait analysis revealed circumduction with the prosthesis for limb advancement and increased vaulting with push off on the sound (uninvolved) limb. Gait retraining strategies were implemented to address video analysis findings and create a more efficient running gait and address phantom limb pain symptoms.

OUTCOMES

Rehabilitation and gait retraining strategies were effective in improving several clinical and functional outcomes in this case. Significant improvements were noted in PLP, running gait mechanics, and the patient's psychological and functional status as measured with a standardized outcome tool, the Patient-Reported Outcomes Measurement Information System® (PROMIS®).

DISCUSSION

Running gait training following amputation could be a crucial component of rehabilitation for athletes in an attempt to lessen pain while running, especially in those experiencing phantom limb pain (PLP). Utilization of a multidisciplinary team in the gait retraining process is recommended. There is a need for further research to determine the effects of running gait retraining for management of PLP in athletes with amputation.

LEVEL OF EVIDENCE

5.

Investigation of The Effects of Prosthetic Knee Condition for Individuals with Transfemoral Amputation During Attempted Running

BACKGROUND

A number of individuals with unilateral transfemoral amputation (TFA) run in a prosthesis with an unlocked prosthetic knee, while others choose to run with a locked prosthetic knee to increase stability. Research regarding running with an unlocked knee (UK) versus a locked knee (LK), with respect to energy efficiency, is limited and might be enhanced by characterization of the impact of knee condition on kinematics.

OBJECTIVES

To investigate the effect of an UK versus LK on hip kinematics, energy efficiency, and running speed.

METHODOLOGY

Five male novice runners with unilateral TFA completed one three-minute self-selected running speed (SSRS) trial and three peak speed trials per knee condition. Hip kinematics, energy efficiency, and running speed were compared between conditions.

FINDINGS

Four of the five subjects exhibited a fast walk, rather than a consistent run. Hip flexion increased for all subjects and hip abduction decreased for four subjects during swing phase for the UK condition. Hip kinematic asymmetry was reduced for the UK condition in the sagittal plane for four individuals; hip kinematic asymmetry was also reduced in the frontal plane for the UK condition for three of these individuals. Mean energy efficiency was better for the UK condition (UK: 0.282 mLO2/kg/m, LK: 0.328 mLO2/kg/m). Peak running speed did not differ significantly between knee conditions (UK: 1.47m/s, LK:1.32m/s).

CONCLUSIONS

For novice recreational runners with unilateral transfemoral amputation, the UK condition resulted in improved energy efficiency and enhanced kinematic symmetry, despite comparable peak speed relative to the LK condition. Therefore the UK condition may be advantageous for mid-range distance running.

Are consumers satisfied with the use of prosthetic sports feet and the provision process? A mixed-methods study

BACKGROUND

Special feet connected to a prosthesis, prosthetic sports feet, enable athletes with a lower limb amputation to run. The selection of a prosthetic sports feet is usually based on body weight and preferred sports performance. The selection of a prosthetic sport feet is also based on clinicians who likely have limited experience due to a small number of athletes with a lower limb amputation.

HYPOTHESIS

Athletes with a lower limb amputation are not satisfied with the use and service associated with prosthetic sports feet due to a lack of prosthetic sports feet provision guidelines, poorer function of prosthetic sports feet compared to the anatomical foot and ankle, and limited experience of clinicians.

EVALUATION OF HYPOTHESIS

A mixed-methods study in 16 athletes with a lower limb amputation using a prosthetic sport foot from Össur or Otto Bock, included semi-structured interviews and quantitative analysis. Three dimensions of prosthetic sports feet were investigated: 1) use, 2) provision process, and 3) cosmetics. Qualitative data were analyzed to identify factors influencing consumer satisfaction. Quantitative data were analyzed to investigate satisfaction and perceived relative importance of the dimensions.

RESULTS

Participants were satisfied with the prosthetic sports feet use. However, they were not satisfied with the process prior to provision. The prosthetic sport feet use was perceived as the most important dimension. Sports performance was the critical element in the prosthetic sports feet use and was influenced by stability, confidence and fear, safety, focus, energy return, and comfort. Cosmetics were unimportant. Motivation to purchase the prosthetic sports feet was the key element for the prosthetic sports foot acquisition. Satisfaction about the process prior to provision was negatively influenced by poor support of professionals during rehabilitation, the complexity and duration of the purchase process, and lack of information and accessibility of prosthetic sports feet.

CONCLUSION

The most important dimension of the prosthetic sports feet was its use, which was directly influenced by performance. To further increase the satisfaction with prosthetic sports feet, clinicians should establish how to meet the desired sports performance level of athletes with a lower limb amputation. Improving the process prior to the provision process may increase satisfaction. We suggest increasing the support of professionals during rehabilitation and training through cooperation between involved services, organizing prosthetic sports feet try-out sessions, and increase the accessibility of the prosthetic sports feet. In this way, individuals with a lower limb amputation may become and stay more physically active and participate in sports.

RETURN TO RUNNING FOLLOWING A KNEE DISARTICULATION AMPUTATION: A CASE REPORT

BACKGROUND AND PURPOSE

The evolution of running-specific prostheses has empowered athletes with lower extremity amputations to run farther and faster than previously thought possible; but running with proper mechanics is still paramount to an injury-free, active lifestyle. The purpose of this case report was to describe the successful alteration of intact limb mechanics from a Rearfoot Striking (RFS) to a Non-Rearfoot Striking (NRFS) pattern in an individual with a knee disarticulation amputation, the associated reduction in Average Vertical Loading Rate (AVLR), and the improvement in functional performance following the intervention.

CASE DESCRIPTION

A 30 year-old male with a traumatic right knee disarticulation amputation reported complaints of residual limb pain with running distances greater than 5 km, limiting his ability to train toward his goal of participating in triathlons. Qualitative assessment of his running mechanics revealed a RFS pattern with his intact limb and a NRFS pattern with his prosthetic limb. A full body kinematic and kinetic running analysis using 3D motion capture and force plates was performed. The average intact limb loading rate was four-times greater (112 body weights/s) than in his prosthetic limb which predisposed him to possible injury. He underwent a three week running intervention with a certified running specialist to learn a NRFS pattern with his intact limb.

OUTCOMES

Immediately following the running intervention, he was able to run distances of over 10 km without pain. On a two-mile fitness test, he decreased his run time from 19:54 min to 15:14 min. Additionally, the intact limb loading rate was dramatically reduced to 27 body weights/s, nearly identical to the prosthetic limb (24 body weights/s).

DISCUSSION

This case report outlines a detailed return to run program that targets proprioceptive and neuromuscular components, injury prevention, and specificity of training strategies. The outcomes of this case report are promising as they may spur additional research toward understanding how to eliminate potential injury risk factors associated with running after limb loss.

LEVEL OF EVIDENCE

4.