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The results of a comparative load and stress evaluation of several different types of below-knee drop-foot braces are presented. The data obtained from this investigation suggest that considerable mechanical improvements can and should be made to the standard designs of braces. It is recommended that this method of investigation be more widely used in the assessment of structural or design changes in orthopedic appliances.

Hip joint loads need careful consideration during postoperative physiotherapy after joint replacement. One factor influencing joint loads is the choice of footwear, but it remains unclear which footwear is favorable. The objective of the present study was to investigate the influence of footwear on hip joint loads in vivo. Instrumented hip endoprostheses were used for in vivo load measurements. The parameters resultant contact force (Fres), bending moment (Mbend) and torsional moment (Mtors) were evaluated during treadmill walking at 4 km/h with different shoe types. In general, footwear tended to increase hip joint loading, with the barefoot shoe having the least influence. Fres and Mbend were significantly increased during heel strike for all shoe types in comparison to barefoot walking, with everyday shoe (34.6%; p = 0.028 and 47%; p = 0.028, respectively) and men’s shoe (33.2%; p = 0.043 and 41.1%; p = 0.043, respectively) resulting in the highest changes. Mtors at AbsMax was increased by all shoes except for the barefoot shoe, with the highest changes for men’s shoe (+ 17.6%, p = 0.043) and the shoe with stiffened sole (+ 17.5%, p = 0.08). Shoes, especially those with stiff soles or elaborate cuishing and guiding elements, increase hip joint loads during walking. The influence on peak loads is higher for Mtors than for Fres and Mbend. For patients in which a reduction of hip joints loads is desired, e.g. during physiotherapy after recent surgery or to alleviate symptoms of osteoarthritis, low profile shoes with a flexible sole may be preferred over shoes with a stiff sole or elaborate cushioning elements.

Gait analysis has traditionally been carried out in a laboratory environment using expensive equipment, but, recently, reliable, affordable, and wearable sensors have enabled integration into clinical applications as well as use during activities of daily living. Real-time gait analysis is key to the development of gait rehabilitation techniques and assistive devices such as neuroprostheses. This article presents a systematic review of wearable sensors and techniques used in real-time gait analysis, and their application to pathological gait. From four major scientific databases, we identified 1262 articles of which 113 were analyzed in full-text. We found that heel strike and toe off are the most sought-after gait events. Inertial measurement units (IMU) are the most widely used wearable sensors and the shank and foot are the preferred placements. Insole pressure sensors are the most common sensors for ground-truth validation for IMU-based gait detection. Rule-based techniques relying on threshold or peak detection are the most widely used gait detection method. The heterogeneity of evaluation criteria prevented quantitative performance comparison of all methods. Although most studies predicted that the proposed methods would work on pathological gait, less than one third were validated on such data. Clinical applications of gait detection algorithms were considered, and we recommend a combination of IMU and rule-based methods as an optimal solution.

The purpose of this study was to quantify movement coupling at the ankle during the stance phase of running using bone-mounted markers. Intracortical bone pins with reflective marker triads were inserted under standard local anaesthesia into the calcaneus and the tibia of five healthy male subjects. The three-dimensional rotations were determined using a joint coordinate system approach. Movement coupling was observed in all test subjects and occurred in phases with considerable individual differences. Between the shoe and the calcaneus coupling increased after midstance which suggested that the test shoes provided more coupling for inversion than for eversion. Movement coupling between calcaneus and tibia was higher in the first phase (from heel strike to midstance) compared with the second phase (from midstance to take-off). This finding is in contrast to previous in-vitro studies but may be explained by the higher vertical loads of the present in-vivo study. Thus, movement coupling measured at the bone level changed throughout the stance phase of running and was found to be far more complex than a simple mitered joint or universal joint model.

Background:Fatigue due to running has been shown to contribute to changes in plantar pressure distribution. However, little is known about changes in foot posture after running. We sought to compare the Foot Posture Index before and after moderate exercise and to relate any changes to plantar pressure patterns.Methods:A baropodometric evaluation was made, using the FootScan platform (RSscan International, Olen, Belgium), of 30 men who were regular runners and their foot posture was examined using the Foot Posture Index before and after a 60-min continuous run at a moderate pace (3.3 m/sec).Results:Foot posture showed a tendency toward pronation after the 60-min run, gaining 2 points in the Foot Posture Index. The total support and medial heel contact areas increased, as did pressures under the second metatarsal head and medial heel.Conclusions:Continuous running at a moderate speed (3.3 m/sec) induced changes in heel strike related to enhanced pronation posture, indicative of greater stress on that zone after physical activity. This observation may help us understand the functioning of the foot, prevent injuries, and design effective plantar orthoses in sport. (J Am Podiatr Med Assoc 103(2): 121–125, 2013)

In comparative studies of various gait patterns of 20 healthy subjects who used a cane, the vertical reaction forces and the center of force on the foot were measured and recorded by a force recording and analyzing device. The results indicated that when a cane was used in the ipsilateral hand, the center of force did not shift significantly compared with normal gait. When a cane was used in the contralateral hand, the center of force shifted medially compared with normal gait. In analysis of the vertical floor reaction force acting on the foot, the most efficient way to use a cane was to control the pacing so that the tip of the cane and the foot touched the ground simultaneously. By doing so, the cane could share as much as 34.3% of force at heel strike, 25.3% at midstance, and 29.7% at toeoff of the stance phase of the gait cycle. When prescribing use of a cane for a patient with varus gonarthritis, the patient should be instructed to use the cane in the ipsilateral hand so as not to shift the center of force medially; for a patient with valgus gonarthritis, the cane should be used in the contralateral hand to shift the center of force medially. Patients should be taught to control pacing so that the tip of the cane and the foot touch the ground simultaneously.

Background It is generally understood that toe walking involves the absence or limitation of heel strike in the contact phase of the gait cycle. Toe walking has been identified as a symptom of disease processes, trauma and/or neurogenic influences. When there is no obvious cause of the gait pattern, a diagnosis of idiopathic toe walking (ITW) is made. Although there has been limited research into the pathophysiology of ITW, there has been an increasing number of contemporary texts and practitioner debates proposing that this gait pattern is linked to a sensory processing dysfunction (SPD). The purpose of this paper is to examine the literature and provide a summary of what is known about the relationship between toe walking and SPD. Method Forty-nine articles were reviewed, predominantly sourced from peer reviewed journals. Five contemporary texts were also reviewed. The literature styles consisted of author opinion pieces, letters to the editor, clinical trials, case studies, classification studies, poster/conference abstracts and narrative literature reviews. Literature was assessed and graded according to level of evidence. Results Only one small prospective, descriptive study without control has been conducted in relation to idiopathic toe walking and sensory processing. A cross-sectional study into the prevalence of idiopathic toe walking proposed sensory processing as being a reason for the difference. A proposed link between ITW and sensory processing was found within four contemporary texts and one conference abstract. Conclusion Based on the limited conclusive evidence available, the relationship between ITW and sensory processing has not been confirmed. Given the limited number and types of studies together with the growing body of anecdotal evidence it is proposed that further investigation of this relationship would be advantageous.

The influence of the mechanical characteristics of certain insole materials in the generation and transmission of heel strike impacts while walking was studied. Three insole materials were selected according to their mechanical characteristics under heel strike impacts. The selection of materials has made it possible to distinguish the effect of rigidity and loss tangent in the transmission of heel strike impacts. A lower rigidity and a high loss tangent have been shown to reduce the transmission of impacts to the tibia. A low rigidity was seen to significantly increase the transmission of impacts from tibia to forehead.

Fifteen inphase muscle transfers to the os calcis from 11 patients with lower motor neuron paralysis were evaluated by means of telemetric electromyography during ambulation. In five of the limbs thus evaluated, electromyographic activity was found to resemble that of the normal triceps surae and had relatively normal proximal muscles. In ten limbs, contraction of the transferred muscle preceded heel strike. This was attributed primarily to proximal muscle weakness, which necessitated premature firing to ensure early knee extension during stance and hence to prevent the knee from buckling during weight-bearing.

When a single-muscle learned behavior was superimposed upon natural human treadmill locomotion, in previous work, it operated as a self-contained behavioral unit. The new behavior altered some features, however, of ongoing stepping patterns. These findings prompted broader consideration of how individual muscle actions combine to form large, patterned ensembles. Accordingly, the present experiment constructed a larger, double-muscle learned behavior to see if it would compete with natural treadmill locomotion or combine with it harmoniously. A demanding requirement was made for in-phase bilateral EMG and contraction by rectus femoris (RF), in opposition to its natural out-of-phase interlimb pattern. EMG bursts were controlled, through computer-assisted operant conditioning, by a flash shortly after left heel strike. The new, double ensemble was conditioned rapidly, within 1-6 days, for all four adults. Harmonious stepping continued, for the most part, with little alteration in step cycle timings. Leg positioning was modified appreciably, however, pointing to complex neural mechanisms. The evidence argued that operant conditioning can construct fine-grained behaviors and also participate powerfully across the full range of single- and interlimb coordination.

Walking can be done in many different ways; we can walk fast or slowly, with small or with large steps. When determining forces, moments or work in walking we should consider that these biomechanical quantities are influenced by the walking pattern. The subject of this paper is the moment and the work of the human calf muscles M.M., soleus and gastrocnemius, which plantarflex the foot. The results are obtained by EMG to force processing. This method, developed in our laboratory, gives its results on-line, so that a large amount of data can be obtained in a short time. Moreover it provides, in contrast to other biomechanical methods, moment and work of a single muscle group only.

Lower limb impairment often causes gait asymmetries that may have side-effects on the vertebral column. This is clinically documented. Because of the function the vertebral column carries out in the human body, it is evident that any knowledge concerning the mechanical loads acting on it be of considerable value. It is a necessary starting point for the understanding of the etiology and evolution of the relevant desorders.