Patellar tendon bearing brace: combined effect of heel clearance and ankle status on foot plantar pressure

Evaluation of a New Patellar Tendon Bearing Brace With Offloading Monitoring and Adjustability: A Pilot Study

Background and Aims

The patellar tendon-bearing (PTB) brace is a crucial device designed to lessen axial forces on the tibia. The newly designed PTB brace allows clinicians to measure offloading amount in the realtime. This study aimed to explore the relationship between a rise in displacement between the foot plate and calf shells of this new PTB brace and changes in the amount of offloading on the tibia.

Methods

This pilot study used a sample of five individuals with midshaft tibia fractures to investigate the effectiveness of the PTB brace under different conditions. The PTB brace was tested in six different conditions, with the displacement between the foot plate and calf shells varying in increments of 0.5 cm, from 1 cm to 3.5 cm.

Results

The new PTB brace provided varying levels of offloading, ranging from 22% to 38%. As the vertical distance between the calf shells and foot plate increased, the offloading levels also increased significantly. The study observed significant differences in weight reduction (p = 0.02) and offloading percentages (p = 0.048) when comparing 1 cm and 1.5 cm displacement.

Conclusion

The findings suggest that maintaining a distance of 1.5 cm or more between the calf shells and foot plate is effective in reducing weight and offloading on the tibia. These results have important implications for clinicians using PTB braces to treat tibia fractures, highlighting the importance of adjusting the displacement of the PTB brace to optimize patient outcomes.

Design and Evaluation of a Patellar Tendon-Bearing Brace with Off-Loading Mechanism on Tibia

The current study aimed to design a patellar-tendon-bearing (PTB) brace capable of measuring and quantifying weight offloading on the tibia. The PTB brace was designed with off-loading mechanism on the tibia with features, including ankle joint, vertical sliding adaptor, vertical sliding piece, and upper connector of load cells to PTB brace. Also, the present study investigated the effect of brace on 20 healthy individuals under 8 different off-loading conditions, based on measuring the vertical distance between the calf shells and foot plate through a sliding adapter at 0.5, 1, 1.5, 2, 2.5, 3, and 3.5 cm. The Pedar device and load cells embedded in PTB brace were used to determine the extent of offloading and assess the reliability and validity of brace. Increasing the vertical distance between the calf shells and the footplate can lead to a greater amount of offloading. Accordingly, off-loading ranged from a minimum of 16.5% at 0 cm position to a maximum of 60.48% at 3.5 cm position of sliding adapter. Percentage values of tibia off-loading in 8 conditions were not significantly different in Padar devices and PTB brace. Therefore, PTB brace load cells, as a valid method, can measure off-loading levels. When fabricating a PTB brace, a monitoring system with load cells is essential to measure the amount of tibial offloading, leading to readjustment if limb slides down inside the brace. Additionally, a component is needed to correctly position limb in off-loading condition. In the current study, sliding adapter of brace can provide that capability.

Foot offloading associated with carbon fiber orthosis use: A pilot study

BACKGROUND

Traumatic lower limb injuries can result in chronic pain. Orthotic interventions are a leading conservative approach to reduce pain, manage loading, and protect the foot. Robust carbon fiber custom dynamic orthoses (CDOs) designed for military service members have been shown to reduce foot loading. However, the effect of carbon fiber orthosis design, including designs widely used in the civilian sector, on foot loading is unknown.

RESEARCH QUESTION

Determine if carbon fiber orthoses alter foot loading during gait.

METHODS

Loadsol insoles were used to measure peak forces and force impulse acting on the forefoot, midfoot, hindfoot, and total foot. Nine healthy, able-bodied individuals participated. Force impulse was quantified as cumulative loading throughout stance phase. Participants walked without an orthosis and with three carbon fiber orthoses of differing designs: a Firm stiffness CDO, a Moderate stiffness CDO, and a medial and lateral strut orthosis (MLSO).

RESULTS

There were significant main effects of orthosis condition on peak forefoot forces as well as forefoot and hindfoot force impulse. Peak forefoot forces were significantly lower in the Moderate and Firm CDOs compared to no orthosis and MLSO. Compared to walking without an orthosis, forefoot force impulse was significantly lower and hindfoot force impulse was significantly greater in all carbon fiber orthoses. Additionally, hindfoot force impulse in the Firm CDO was significantly higher than in the MLSO and Moderate CDO.

SIGNIFICANCE

The three carbon fiber orthosis designs differed regarding foot loading, with more robust orthoses providing greater forefoot offloading. Orthosis-related changes in forefoot loading suggest that carbon fiber orthoses could reduce loading-associated pain during gait. However, increased hindfoot force impulse suggests caution should be used when considering carbon fiber orthoses for individuals at risk of skin breakdown with repetitive loading.

Walking with unilateral ankle-foot unloading: a comparative biomechanical analysis of three assistive devices

BACKGROUND

Foot and ankle unloading is essential in various clinical contexts, including ulcers, tendon ruptures, and fractures. Choosing the right assistive device is crucial for functionality and recovery. Yet, research on the impact of devices beyond crutches, particularly ankle-foot orthoses (AFOs) designed to unload the ankle and foot, is limited. This study investigates the effects of three types of devices-forearm crutches, knee crutch, and AFO-on biomechanical, metabolic, and subjective parameters during walking with unilateral ankle-foot unloading.

METHODS

Twenty healthy participants walked at a self-selected speed in four conditions: unassisted able-bodied gait, and using three unloading devices, namely forearm crutches, iWalk knee crutch, and ZeroG AFO. Comprehensive measurements, including motion capture, force plates, and metabolic system, were used to assess various spatiotemporal, kinematic, kinetic, and metabolic parameters. Additionally, participants provided subjective feedback through questionnaires. The conditions were compared using a within-subject crossover study design with repeated measures ANOVA.

RESULTS

Significant differences were found between the three devices and able-bodied gait. Among the devices, ZeroG exhibited significantly faster walking speed and lower metabolic cost. For the weight-bearing leg, ZeroG exhibited the shortest stance phase, lowest braking forces, and hip and knee angles most similar to normal gait. However, ankle plantarflexion after push-off using ZeroG was most different from normal gait. IWalk and crutches caused significantly larger center-of-mass mediolateral and vertical fluctuations, respectively. Participants rated the ZeroG as the most stable, but more participants complained it caused excessive pressure and pain. Crutches were rated with the highest perceived exertion and lowest comfort, whereas no significant differences between ZeroG and iWalk were found for these parameters.

CONCLUSIONS

Significant differences among the devices were identified across all measurements, aligning with previous studies for crutches and iWalk. ZeroG demonstrated favorable performance in most aspects, highlighting the potential of AFOs in enhancing gait rehabilitation when unloading is necessary. However, poor comfort and atypical sound-side ankle kinematics were evident with ZeroG. These findings can assist clinicians in making educated decisions about prescribing ankle-foot unloading devices and guide the design of improved devices that overcome the limitations of existing solutions.

Passive Articulated and Non-Articulated Ankle-Foot Orthoses for Gait Rehabilitation: A Narrative Review

The aim of this work was to study the different types of passive articulated and non-articulated ankle-foot orthoses for gait rehabilitation in terms of working principles, control mechanisms, features, and limitations, along with the recent clinical trials on AFOs. An additional aim was to categorize them to help engineers and orthotists to develop novel designs based on this research. Based on selected keywords and their composition, a search was performed on the ISI Web of Knowledge, Google Scholar, Scopus, and PubMed databases from 1990 to 2022. Forty-two studies met the eligibility criteria, which highlighted the commonly used types and recent development of passive articulated and non-articulated ankle-foot orthoses for foot drop. Orthotists and engineers may benefit from the information obtained from this review article by enhancing their understanding of the challenges in developing an AFO that meets all the requirements in terms of ease of use, freedom of movement, and high performance at a relatively low cost.

Commonly Used Types and Recent Development of Ankle-Foot Orthosis: A Narrative Review

(1) Background: ankle-foot orthosis (AFO) is the most commonly prescribed orthosis to patients with foot drop, and ankle and foot problems. In this study, we aimed to review the commonly used types of AFO and introduce the recent development of AFO. (2) Methods: narrative review. (3) Results: AFO prevents the foot from being dragged, provides a clearance between the foot and the ground in the swinging phase of gait, and maintains a stable posture by allowing heel contact with the ground during the stance phase. In clinical practice, the most commonly used AFO include plastic AFO, walking boot, UD-Flex, and carbon fiber AFO. In addition, for compensating the demerits of these conventional AFOs, new types of AFOs, including AF Servo, TurboMed, three-dimensionally printed AFO, and AFO made from kenaf composites, were developed. (4) Conclusions: we think that our review can guide clinicians in selecting and prescribing the appropriate AFO for each patient in accordance with their specific physical conditions.

Biomechanical Comparison of a New Dynamic Ankle Orthosis to a Standard Ankle-Foot Orthosis During Walking

Patients who sustain irreversible cartilage damage or joint instability from ankle injuries are likely to develop ankle osteoarthritis (OA). A dynamic ankle orthosis (DAO) was recently designed with the intent to offload the foot and ankle using a distractive force, allowing more natural sagittal and frontal plane ankle motion during gait. To evaluate its efficacy, this study compared ankle joint kinematics and plantar pressures among the DAO, standard double upright ankle-foot orthosis (DUAFO), and a nonorthosis control (CON) condition in healthy adults during walking. Ten healthy subjects (26 ± 3.8 yr; 69.6 ± 12.7 kg; and 1.69 ± 0.07 m) walked on a treadmill at 1.4 m/s in three orthosis conditions: CON, DAO, and DUAFO. Ankle kinematics were assessed using a three-dimensional (3D) motion capture system and in-shoe plantar pressures were measured for seven areas of the foot. DAO reduced hallux peak plantar pressures (PPs) compared to CON and DUAFO. PPs under toes 2-5 were smaller in DAO than DUAFO, but greater in DUAFO compared to CON. Early stance peak plantarflexion (PF) angular velocity was smaller in DAO compared to CON and DUAFO. Eversion (EV) ROM was much smaller in DUAFO compared to CON and DAO. Early stance peak eversion angular velocity was smaller in DAO and much smaller in DUAFO compared to CON. This study demonstrates the capacity of the DAO to provide offloading during ambulation without greatly affecting kinematic parameters including frontal plane ankle motion compared to CON. Future work will assess the effectiveness of the DAO in a clinical osteoarthritic population.

Shorter recovery can be achieved from using walking boot after operative treatment of an ankle fracture

Background/Objective

Ankle fractures, even if treated surgically, usually take a long time to heal. For all patients with ankle fracture, immobilisation is a critical part of treatment. Short-leg walking boots (WBs) have been reported to be an effective alternative to plaster casts (PCs) that could shorten this postoperative recuperative period. The aim of this study was to compare the functional recovery of a conventional PC with that of a WB after surgery for ankle fractures.

Methods

Forty-seven patients (mean age, 53.9 ± 12 years) who had undergone surgical operation for an unstable ankle fracture from January 2008 to October 2014 were reviewed retrospectively. Either a PC or a WB was prescribed postoperatively, with 25 patients and 22 patients, respectively. The time that it took the patient to stand unipedal on the affected side after allowing full-weight bear and to walk without crutches were used for assessment of functional recovery. The prevalence of postoperative loss of reduction and nonunion was also reviewed.

Results

Both the time of being able to stand unipedal on the injured side and to walk without crutches were significantly shorter in patients using WBs (WB, 2.6 weeks; PC, 4.5 weeks, p = 0.01; WB, 1.4 weeks; PC, 3.1 weeks, p = 0.03). There were no patients with loss of reduction or nonunion.

Conclusion

Patients who used WBs showed a significantly faster recovery. WBs have an adjustable heel lift that allows users to change the ankle position slightly plantarflexed that helps walking in a postoperative swollen ankle. WBs are easy to slip on, and it is easy to adjust the ankle position in conformity with swelling so that the least painful position could be maintained during walking. WBs have good fixity to allow immediate weight-bearing postoperatively, and there were no cases with loss of reduction postoperatively. The Rocker bottom design minimises the sagittal plane motion in the specific joint of the foot, which also facilitates the course of recuperation. An ankle fracture fixed appropriately endures loading when a WB is used. The WB treatment results in faster functional recovery, allowing the patients to return to normal activity at a faster rate.