Forearm pressure distribution during ambulation with elbow crutches: a cross-sectional study

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.

Versatile GCH Control Software for Correction of Loads Applied to Forearm Crutches During Gait Recovery Through Technological Feedback: Development and Implementation Study

Background

Measuring weight bearing is an essential aspect of clinical care for lower limb injuries such as sprains or meniscopathy surgeries. This care often involves the use of forearm crutches for partial loads progressing to full loads. Therefore, feasible methods of load monitoring for daily clinical use are needed.

Objective

The main objective of this study was to design an innovative multifunctional desktop load-measuring software that complements GCH System 2.0–instrumented forearm crutches and monitors the applied loads, displaying real-time graphical and numerical information, and enabling the correction of inaccuracies through feedback technology during assisted gait. The secondary objective was to perform a preliminary implementation trial.

Methods

The software was designed for indoor use (clinics/laboratories). This software translates the crutch sensor signal in millivolts into force units, records and analyzes data (10-80 Hz), and provides real-time effective curves of the loads exerted on crutches. It covers numerous types of extrinsic feedback, including visual, acoustic (verbal/beeps), concurrent, terminal, and descriptive feedback, and includes a clinical and research use database. An observational descriptive pilot study was performed with 10 healthy subjects experienced in bilateral assisted gait. The Wilcoxon matched-pairs signed-rank test was used to evaluate the load accuracy evolution of each subject (ie, changes in the loads exerted on crutches for each support) among various walks, which was interpreted at the 95% confidence level.

Results

GCH Control Software was developed as a multifunctional desktop tool complementing GCH System 2.0–instrumented forearm crutches. The pilot implementation of the feedback mechanism observed 96/100 load errors at baseline (walk 0, no feedback) with 7/10 subjects exhibiting crutch overloading. Errors ranged from 61.09% to 203.98%, demonstrating heterogeneity. The double-bar feedback found 54/100 errors in walk 1, 28/100 in walk 2, and 14/100 in walk 3. The first walk with double-bar feedback (walk 1) began with errors similar to the baseline walk, generally followed by attempts at correction. The Wilcoxon matched-pairs signed-rank test used to evaluate each subject’s progress showed that all participants steadily improved the accuracy of the loads applied to the crutches. In particular, Subject 9 required extra feedback with two single-bar walks to focus on the total load. The participants also corrected the load balance between crutches and fluency errors. Three subjects made one error of load balance and one subject made six fluctuation errors during the three double-bar walks. The latter subject performed additional feedback with two balance-bar walks to focus on the load balance.

Conclusions

GCH Control Software proved to be useful for monitoring the loads exerted on forearm crutches, providing a variety of feedback for correcting load accuracy, load balance between crutches, and fluency. The findings of the complementary implementation were satisfactory, although clinical trials with larger samples are needed to assess the efficacy of the different feedback mechanisms and to select the best alternatives in each case.

Injuries Associated with Crutch Use: A Narrative Review

Crutches are commonly prescribed in physiatric settings to help offload the lower extremities. Crutch use, however, results in abnormal and repetitive weight-bearing through the upper extremities that may result in secondary injury. This narrative review investigates injury types and risk factors associated with crutch use in order to guide healthcare providers on injury prevention strategies. Medline, EMBASE, CINAHL, and the Cochrane Library were systematically reviewed for publications between 1950 and 2018 on neurological, musculoskeletal, or vascular complications associated with crutch use. Titles and abstracts (n = 2395) were screened by two authors. Sixty studies were eligible. Articles were reviewed for level of evidence, crutch type, participant characteristics, and injury characteristics. There were 42 axillary crutch studies, 12 forearm crutch studies, and 6 studies that did not specify crutch type. These studies incorporated 622 individuals, and most were case series or case reports (n = 54). Axillary crutch use was most commonly associated with axillobrachial arterial complications due to pressure from the axillary bar (n = 34). Forearm crutch use was most commonly associated with compressive neuropathies due to pressure from the forearm cuff (n = 6). Improper crutch fitting and/or use were identified as contributing factors to injury in 22 cases. Duration of crutch use and medical comorbidities also influenced the types of injuries seen. There are rare but potentially serious complications associated with crutch use. When prescribing crutches, clinicians should ensure they are properly fit, engage in appropriate gait training, be aware of common crutch-related injuries, and consider potential patient-specific injury risk factors in order to minimize injury risk.

Pain mapping and health-related conditions in relation to forearm crutch usage: A cross-sectional study

To explore pain complaints and health-related conditions, verifying if permanent or temporary usage of forearm crutches could be associated with them. We designed a cross-sectional study from a sample who answered a five-month public call. We organized data into five domains: (1) diseases, signs and symptoms; (2) personal factors related to age, sex, marital status, and paid occupation; (3) body structure and functional components defined by body mass index, arterial pressure, mental state, and pain; (4) activities and participation assessed by satisfaction with Assistive Technology; (5) and environmental factors focused on medicines and forearm crutch usage. The sample was geo-referenced by address, and the frequency of the codified health conditions was distributed according to ICD-10's chapters. We recruited three times more permanent than temporary users dealing with chronic and external causes of diseases. Pain mapping suggested different pattern of complaints between permanent and temporary users. Women who were temporary users seemed more likely to be injured because of external causes. Moreover, both users reported intense (31%) and moderate (53%) levels of pain. In contrast, mild pains were only reported by permanent users (16%), suggesting a distinction between acute and chronic pain according to the kind of forearm crutch usage.

Developing Innovative Crutch Using IDeS (Industrial Design Structure) Methodology

The present study wants to bring to light a new type of crutch designed for a chronic patient with perennial limited mobility, who must use this support every time a move is needed. The main purpose of the project consists in recommending a correct use of the crutch through technology, limiting the damage normally caused by a bad use of crutches and giving a support both for the patient and for the doctor. All of the features of the crutches were defined through relationship matrices and a benchmarking, which helped us for defining the requirements; other important features were defined, taking a look to the technological progresses applied to new, patented crutches. The result is a sensorized crutch, functional and oriented to meet the user’s needs in order to prevent an incorrect use of the support avoiding the growth of other pains.

Biomechanics of single-leg running using lofstrand crutches in amputee soccer

[Purpose] Amputee soccer is a game for individuals with amputations. Players use lofstrand crutches to move around the field and kick the ball. Scoring quick goals during a match requires players to have maximum running skills. Notably, a few parameters affect the running speed in players; however, no study has reported the biomechanical analysis of running in amputee soccer. Thus study aimed to analyze the biomechanics of single-leg running using lofstrand crutches in 12 healthy adult males (6 with prior amputee soccer experience and 6 without such experience). [Participants and Methods] The kinematics of the lower limb and the pelvis, the ground reaction force, and skill in using the crutches were evaluated using 3 dimensional motion analysis combined with 8 force plates. Lower leg amputation was simulated in all participants by maintaining the non-dominant knee in a position of maximum flexion using an elastic band. [Results] Significant differences were observed between experienced and non-experienced participants with regard to the angle of the pelvis and the crutch stance phase. Specifically, higher running speed was associated with an increased forward tilt of the pelvis and a shorter crutch stance phase. [Conclusion] These findings will be useful to improve the running speed of amputee soccer players.

Influence of the load exerted over a forearm crutch in spatiotemporal step parameters during assisted gait: pilot study

BACKGROUND

Assisted gait with forearm crutches is frequently performed during the recovery of musculoskeletal injuries of the lower limb. The amount of body weight applied to the crutch or crutches depends on the pathology and the treatment phase. The transition from assisted gait with two crutches to a single crutch is usually recommended when the subject is able to load the 50% of the body weight upon the affected member. An altered assisted gait will cause biomechanic alterations and, therefore, longer treatments and relapses. The aim of this study was to analyze the influence of 10, 25 and 50% of body weight applied to a forearm crutch during a unilateral assisted gait in the spatial and temporal step parameters to determine the load that produces alterations in gait biomechanics and the load that does not.

METHODS

Eleven healthy subjects performed normal gait (NG) and assisted gait with a forearm crutch, in which the applied loads were: comfortable (C), 25 and 50% of their body weight. Vicon System was employed for gait recording. GCH System 2.0 and GCH Control Software 1.0 controlled the loads. The variables were: step length, step period, velocity, step width and step angle. Friedman test compared all the gait modalities: NG and the different loads. Wilcoxon signed-rank test analyzed ipsilateral and contralateral step parameters to the crutch globally and for each subject.

RESULTS

Friedman test showed significant differences between NG, C, 25 and 50%, especially for step period and velocity. Wilcoxon test had significant differences only in 4 of the 20 general comparisons between ipsilateral and contralateral steps to the crutch. In the analysis by subjects, step length, step period and velocity showed 79/132, 110/132 and 58/66 significant differences, respectively.

CONCLUSIONS

The increase in the load exerted over a forearm crutch produced an increase in the step period, accompanied by a reduction of step length and gait velocity. Step width and step angle were not modified. The unloading of 25 and 50% of body weight on a single crutch is incorrect from the biomechanical point of view. Two crutches should be employed when the body weight to unload exceeds 10%.

Load distribution on the foot and lofstrand crutches of amputee football players

BACKGROUND

Amputee football is a worldwide popular sport with positive physical and psychological effects on the disabled. Amputee players use their hands dominantly for locomotion. However, the effect of using upper extremity which is not accommodated to loading is not very well known.

RESEARCH QUESTION

The objective of this study was to determine the load distribution of amputee football players during walking, running and kicking the ball.

METHODS

This study was conducted with 15 certified amputee football players (age 24.5 ± 5.8 years, body weight 62.3 ± 10.9 kg, height 171.6 ± 7.7 cm). The loads on their non-amputated lower extremity were measured with F-Scan mobile system sensors inserted in their shoes, and the loads on their upper extremities were measured with F-Grip system sensors affixed to the gloves. The participants were asked to walk, run and kick the ball using Lofstrand Crutches.

RESULTS

The maximum loading on the upper extremities during walking, running and kicking the ball varied between 111% and 175% of the body weight. While loading during walking and running was similar, the loading on the upper extremity during kicking the ball exceeded that of walking by 58.1% and running by 47.4%. The maximum loading on the non-amputated lower extremity varied between 134% and 196% of the body weight. Loading during running was 46.2% higher than that of walking. The loading on the foot during kicking the ball was 45.7% higher than that of walking. The loading on the foot during running and kicking were similar.

SIGNIFICANCE

Walking-running-kicking the ball with LC resulted in unusual loading particularly on the upper extremity. During running, the increased loading was transferred to the foot rather than the hands. During kicking, the loading increased extremely and was mainly transferred to the hands. The frequent repetition of kicking during the game may therefore increase the incidence of upper extremity injuries.

Shoulder joint loadings in post total hip replacement surgery patients during assisted walking: The influence of the crutch setup

A crutch is prescribed to permit the patient to walk safely and independently immediately after total hip replacement (THR) surgery. Purpose of this study is to evaluate the influence of the crutch setup on upper limbs biomechanics, including shoulder joint kinematics and kinetics parameters that will be evaluated to detect possible differences related to the crutch length. Thirty patients were randomly assigned to elbow flexed (EF) or elbow extended (EE) forearm crutch setup. Subjects were asked to walk on the laboratory path, instrumented with motion tracking system and force platforms. Spatiotemporal gait parameters, crutch ground reaction force (GRF) and crutch displacement (measured as the relative distance between the crutch position on the floor and the shoulder joint center), were evaluated. A three-dimensional (3D) biomechanical model was implemented to determine shoulder joint kinematics and kinetics during crutch walking. Results showed that the stride length significantly decreased, and base of support width increased for the EF group when compared to the EE group. Crutch forces and distance to the body significantly decreased in the EE group. Furthermore, shoulder joint moments in all planes of motion, vertical and lateral forces were significantly reduced in the EE group. The present study showed that crutch setup influenced performance and upper limb loading during walking, with EE setup allowing a more stable walking and reducing stress on the shoulder joint when compared to the EF setup. Results may help therapists in rationalizing crutch length adjustments for patients after THR surgery.

The impact of non weight bearing: A prospective cohort study

BACKGROUND

Patients with lower limb injuries are commonly advised to non weight bear (NWB) on their injured limb as part of treatment. Occasionally, patients complain that offloading one limb, associated with the use of crutches or other mobility aids, may lead to pain on one of the other supporting limbs. This has led to compensation claims (1) but has never been the subject of formal research.

METHODS

A prospective cohort trial was undertaken to address this question. Patients were recruited from two Metropolitan Hospital Orthopaedic Fracture Clinics and Orthopaedic Wards. A survey was administered at two time points; the first at the point of definitive orthopaedic treatment and commencement of the NWB phase. The second after the NWB phase was completed. The surveys included a pain Visual Analogue Scale (VAS), Short Form (SF)12, a pain body chart and a health questionnaire.

RESULTS

A total of 55 patients were enrolled in the study. Seven patients developed new joint pain after a period NWB. These patients scored significantly lower on the follow up SF12 when compared to those who did not develop new pain (p=0.045). Follow up phone calls at least 6 months following completion of the second survey revealed that all initial and new pain areas in these participants had resolved. The main limitation of this study was the limited numbers.

CONCLUSION

This study supports the idea that crutches, prescribed in the short term to allow a limb to be NWB, achieve this aim with minimal impact. Their use may be associated with new other joint pain however it can be anticipated this will resolve after cessation of crutch use.

Prospective clinical evaluation of a novel anatomic cuff for forearm crutches in patients with osteoarthritis

Background

The use of forearm crutches has been associated with pain and neuropraxia along the ulnar bone. Whilst anatomic grips have improved comfort of crutch walking, to date anatomic forearm cuffs have not been clinically evaluated. The aim of this clinical pilot study was to determine if the use of forearm crutches with anatomic cuffs reduces pain and increases comfort and function in long-term users of forearm crutches during a 4-week period.

Method

Prospective study in ten patients suffering from end-stage osteoarthritis of the lower extremity. All participants were long-term users of conventional forearm crutches. Participants used forearm crutches with an anatomically shaped cuff for 4-weeks. General health was assessed using the SF-36, and the crutches were evaluated using a newly developed questionnaire focusing on symptoms along the forearm.

Results

Pain and paresthesia along the forearms decreased by 3.3 points (95% confidence interval difference (CI): [−5.0; −1.6], p = .004) and 3.5 points (95%CI: [−5.1; −1.9], p = .002), respectively, after using the crutches with the new anatomic cuff for 4 weeks. Comfort and sense of security of crutch use increased by 3.0 points (95%CI: [1.3; 4.7], p = .007) and 2.4 points (95%CI: [0.7; 4.1], p = .024). Cross-correlation analysis revealed correlations among items in the same item category and no correlations between items of different item categories of the new questionnaires.

Conclusion

An anatomically shaped cuff increases comfort of forearm crutches. Further research should confirm long-term clinical improvement.

Trial registration

This study was registered retrospectively in ISRCTN (TRN: ISRCTN 11135150) on 14/02/2017.

Reduction in ulnar pressure distribution when walking with forearm crutches with a novel cuff design: Cross-sectional intervention study on the biomechanical efficacy of an ulnar recess

Walking with crutches is an effective way of reducing the load on the lower extremity and is often indicated after injury or surgery. However, walking with forearm crutches with conventional cuffs can trigger symptoms including tenosynovitis in the biceps tendon, ulnar neuropraxia at the wrist, pain, or skin hematoma. The purpose of this study was to test the hypothesis that a crutch cuff design with an ulnar recess reduces ulnar pressure during walking with forearm crutches. The pressure distribution between the forearm and crutch cuff was measured in 15 healthy participants for crutch walking with conventional and novel cuffs, respectively. Relative peak pressure in the proximal medial region compared to the overall peak pressure was reduced by 8.6% when walking with crutches with the novel cuff design compared to conventional cuffs (p < 0.001). Relative peak pressure in the distal intermediate and lateral regions were increased by 3.3% and 3.7% for the novel compared with conventional cuffs, respectively (p < 0.001 for both). Hence, the novel crutch cuffs shifted regions of high pressure away from the proximal ulnar region towards more distal regions that are covered by more soft tissue.

A Compact Forearm Crutch Based on Force Sensors for Aided Gait: Reliability and Validity

Frequently, patients who suffer injuries in some lower member require forearm crutches in order to partially unload weight-bearing. These lesions cause pain in lower limb unloading and their progression should be controlled objectively to avoid significant errors in accuracy and, consequently, complications and after effects in lesions. The design of a new and feasible tool that allows us to control and improve the accuracy of loads exerted on crutches during aided gait is necessary, so as to unburden the lower limbs. In this paper, we describe such a system based on a force sensor, which we have named the GCH System 2.0. Furthermore, we determine the validity and reliability of measurements obtained using this tool via a comparison with the validated AMTI (Advanced Mechanical Technology, Inc., Watertown, MA, USA) OR6-7-2000 Platform. An intra-class correlation coefficient demonstrated excellent agreement between the AMTI Platform and the GCH System. A regression line to determine the predictive ability of the GCH system towards the AMTI Platform was found, which obtained a precision of 99.3%. A detailed statistical analysis is presented for all the measurements and also segregated for several requested loads on the crutches (10%, 25% and 50% of body weight). Our results show that our system, designed for assessing loads exerted by patients on forearm crutches during assisted gait, provides valid and reliable measurements of loads.

Reliability and Validity Study of the Chamorro Assisted Gait Scale for People with Sprained Ankles, Walking with Forearm Crutches

Objective

The aim of this study was to design and validate a functional assessment scale for assisted gait with forearm crutches (Chamorro Assisted Gait Scale—CHAGS) and to assess its reliability in people with sprained ankles.

Design

Thirty subjects who suffered from sprained ankle (anterior talofibular ligament first and second degree) were included in the study. A modified Delphi technique was used to obtain the content validity. The selected items were: pelvic and scapular girdle dissociation(1), deviation of Center of Gravity(2), crutch inclination(3), steps rhythm(4), symmetry of step length(5), cross support(6), simultaneous support of foot and crutch(7), forearm off(8), facing forward(9) and fluency(10). Two raters twice visualized the gait of the sample subjects which were recorded. The criterion-related validity was determined by correlation between CHAGS and Coding of eight criteria of qualitative gait analysis (Viel Coding). Internal consistency and inter and intra-rater reliability were also tested.

Results

CHAGS obtained a high and negative correlation with Viel Coding. We obtained a good internal consistency and the intra-class correlation coefficients oscillated between 0.97 and 0.99, while the minimal detectable changes were acceptable.

Conclusion

CHAGS scale is a valid and reliable tool for assessing assisted gait with crutches in people with sprained ankles to perform partial relief of lower limbs.

Analysis of terrain effects on the interfacial force distribution at the hand and forearm during crutch gait

Forces transferred to the upper body during crutch use can lead to both short-term and long-term injuries, including joint pain, crutch palsy, and over-use injuries. While this force transmission has been studied in controlled laboratory settings, it is unclear how these forces are affected by irregular terrains commonly encountered during community ambulation. The purpose of this study was to determine the effects of walking speed and uneven terrain on the load magnitude, distribution, and rate of loading at the human-crutch contact surfaces. Our results show that the rates of loading were significantly increased with higher walking speeds and while negotiating certain irregular terrains, despite there being no apparent effect on the peak force transmission, suggesting load rate may be a more appropriate metric for assessing terrain effects on crutch gait. Furthermore, irrespective of the type of terrain and walking condition, the largest compressive forces were found to reside in the carpal-tunnel region of the hand, and may therefore be a primary contributor to carpal-tunnel injury.

Hand Grip Strength Vs. Sprint Effectiveness in Amputee Soccer Players

Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 – 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed.