The effects of surface slope on multi-segment foot kinematics in healthy adults

Evaluating the use of a novel low-cost measurement insole to characterise plantar foot strain during gait loading regimes

Introduction: Under plantar loading regimes, it is accepted that both pressure and shear strain biomechanically contribute to formation and deterioration of diabetic foot ulceration (DFU). Plantar foot strain characteristics in the at-risk diabetic foot are little researched due to lack of measurement devices. Plantar pressure comparatively, is widely quantified and used in the characterisation of diabetic foot ulceration risk, with a range of clinically implemented pressure measurement devices on the market. With the development of novel strain quantification methods in its infancy, feasibility testing and validation of these measurement devices for use is required. Initial studies centre on normal walking speed, reflecting common activities of daily living, but evaluating response to differing gait loading regimes is needed to support the use of such technologies for potential clinical translation. This study evaluates the effects of speed and inclination on stance time, strain location and strain response using a low-cost novel strain measurement insole. Methods: The STrain Analysis and Mapping of the Plantar Aspect (STAMPS) insole has been developed, and feasibility tested under self-selected normal walking speeds to characterise plantar foot strain, with testing beyond this limited regime required. A treadmill was implemented to standardise speed and inclination for a range of daily plantar loading conditions. A small cohort, comprising of five non-diabetic participants, were examined at slow (0.75 m/s), normal (1.25 m/s) and brisk (2 m/s) walking speeds and normal speed at inclination (10% gradient). Results: Plantar strain active regions were seen to increase with increasing speed across all participants. With inclination, it was seen that strain active regions reduce in the hindfoot and show a tendency to forefoot with discretionary changes to strain seen. Stance time decreases with increasing speed, as expected, with reduced stance time with inclination. Discussion: Comparison of the strain response and stance time should be considered when evaluating foot biomechanics in diabetic populations to assess strain time interval effects. This study supports the evaluation of the STAMPS insole to successfully track strain changes under differing plantar loading conditions and warrants further investigation of healthy and diabetic cohorts to assess the implications for use as a risk assessment tool for DFU.

Foot kinematics and leg muscle activation patterns are altered in those with limited ankle dorsiflexion range of motion during incline walking

BACKGROUND

Larger ankle dorsiflexion (DF) is required when walking on inclined surfaces. Individuals with limited DF range of motion (ROM) may experience greater tissue stress on sloped surfaces and walk in altered gait patterns compared to the those with normal DF ROM.

RESEARCH QUESTION

Would the individuals with limited DF ROM walk with distinctive ankle DF patterns compared to those with normal DF ROM on the inclined surfaces?

METHODS

Ten Limited DF ROM (passive ROM=35.3 ± 2.7°) and nine Normal DF ROM (passive ROM=46.4 ± 4.2°) participants walked on a treadmill at five slope angles (0°, 5°, 10°, 15°, 20°) for 2 min at a self-selected speed. The peak DF angles and the peak myoelectric activity levels of the tibialis anterior (TA) and soleus (SOL) muscles were quantified during the swing and stance phases of each walking trial, and they were compared between the two groups.

RESULTS

Participants with limited DF ROM walked with smaller peak DF (3.1° at 0° slope ~ 8.4° at 20° slope) and greater peak TA activity in swing than those of the Normal ROM participants (3.4° ~ 12.2°), with significant differences at 20° slope. The peak DF angle in stance (Limited: 9.6° ~ 19.0°; Normal: 10.1° ~ 21.0°) did not differ between the two groups at all slopes, but the peak activity of the SOL muscle was significantly greater for the Limited group at slopes of 10° and higher.

SIGNIFICANCE

Study results indicate that incline walking could be more challenging to the individuals with limited DF ROM as they need to approach and push-off the sloped surfaces with more efforts of the dorsiflexor and the plantar flexor muscles, respectively. Prolonged walking on inclined surfaces may produce faster development of muscle fatigue or tissue damage than those with normal DF ROM.

Kneeling trunk kinematics during simulated sloped roof shingle installation

Trunk musculoskeletal disorders are common among residential roofers. Addressing this problem requires a better understanding of the movements required to complete working tasks, such as affixing shingles on a sloped residential roof. We analyzed the extent to which the trunk kinematics during a shingling process are altered due to different angles of roof slope. Eight male subjects completed a kneeling shingle installation process on three differently sloped roof surfaces. The magnitude of the trunk kinematics was significantly influenced by both slope and task phase of the shingling process, depending on the metric. The results unequivocally point to roof slope and task phase as significant factors altering trunk kinematics. However, extension of the results to roofing workers should be done carefully, depending on the degree to which the study protocol represents the natural setting. Future studies on shingle installation in residential roofing should absolutely consider capturing a wider array of shingling procedures in order to encapsulate all the possible methods that are used due to the lack of a standardized procedure.

Multisegment Foot Models and Clinical Application After Foot and Ankle Trauma: A Review

Since the end of the 1990s, several multisegment foot models (MSFMs) have been developed. Several models were used to describe foot and ankle kinematics in patients with foot and ankle pathologies; however, the diagnostic value for clinical practice of these models is not known. This review searched in the literature for studies describing kinematics in patients after foot and ankle trauma using an MSFM. The diagnostic value of the MSFMs in patients after foot and ankle trauma was also investigated. A search was performed on the databases PubMed/MEDLINE, Embase, and Cochrane Library. To investigate the diagnostic value of MSFMs in patients after foot and ankle trauma, studies were classified and analyzed following the diagnostic research questions formulated by Knottnerus and Buntinx. This review was based on 7 articles. All studies were published between 2010 and 2015. Five studies were retrospective studies, and 2 used an intervention. Three studies described foot and ankle kinematics in patients after fractures. Four studies described foot and ankle kinematics in patients after ankle sprain. In all included studies, altered foot and ankle kinematics were found compared with healthy subjects. No results on patient outcome using MSFMs and costs were found. Seven studies were found reporting foot and ankle kinematics in patients after foot and ankle trauma using an MSFM. Results show altered kinematics compared with healthy subjects, which cannot be seen by other diagnostic tests and add valuable data to the present literature; therefore, MSFMs seem to be promising diagnostic tools for evaluating foot and ankle kinematics. More research is needed to find the additional value for MSFMs regarding patient outcome and costs.

How do children with bilateral spastic cerebral palsy manage walking on inclines?

BACKGROUND

Walking on inclined surfaces is an everyday task, which challenges stability and propulsion even in healthy adults. Children with cerebral palsy adapt similarly to inclines like healthy children do. However, how stability and propulsion in these subjects are influenced by different inclines remained unaddressed as of yet.

RESEARCH QUESTION

The aim was to examine the feeling of safety, stability and propulsion of children with cerebral palsy when walking on inclines to gain insight into the challenges they might face on these conditions.

METHODS

Eighteen children with bilateral spastic cerebral palsy with gross motor function classification scale level I and II and nineteen healthy children underwent instrumented 3D gait analysis on level ground and on a 5° and a 10° incline. A mixed linear model was used to draw between and within group comparisons.

RESULTS

Reduced lateral trunk sway, a relative lengthening of the lower limb at initial contact and a controlled walking speed were employed during downhill gait compared to level walking. Patients showed an increased sagittal ROM of trunk (3-4°) and pelvis (2-3°) and a decreased sagittal knee ROM (13°) compared to the typically developed children. During uphill gait, an insufficient increase of push-off power at the ankle (increase by 0.48 W/kg) was noted in children with CP, which appeared to lead to particularly shorter strides (about 0.1 m) in patients compared to healthy children (increase by 1.32 W/kg).

SIGNIFICANCE

Depending on inclination angle, children with cerebral palsy managed to walk on inclines in a controlled manner. The steeper the incline, the more the gait appeared to be affected: decreased feeling of safety, increased need for stabilising mechanisms for downhill gait and less sufficient uphill propulsion were seen. Helping these patients to attain better control during downhill gait and strengthening uphill gait mechanisms may support their participation in everyday life.

Center of pressure and center of mass behavior during gait initiation on inclined surfaces: A statistical parametric mapping analysis

This study analyzed gait initiation (GI) on inclined surfaces with 68 young adult subjects of both sexes. Ground reaction forces and moments were collected using two AMTI force platforms, of which one was in a horizontal position and the other was inclined by 8% in relation to the horizontal plane. Departing from a standing position, each participant executed three trials in the following conditions: horizontal position (HOR), inclined position at ankle dorsi-flexion (UP), and inclined position at ankle plantar-flexion (DOWN). Statistical parametric mapping analysis was performed over the entire center of pressure (COP) and center of mass (COM) time series. COP excursion did not show significant differences in the medial-lateral (ML) direction in both inclined conditions, but it was greater in the anterior-posterior (AP) direction for both inclined conditions. COP velocities are smaller in discrete portions of GI for the UP and DOWN conditions. COM displacement was greater in the ML direction during anticipatory postural adjustments (APA) in the UP condition, and COM moves faster in the ML direction during APA in the UP condition but slower at the end of GI for both the UP and the DOWN conditions. The COP-COM vector showed a greater angle in the DOWN condition. We observed changes for COP and COM in GI in both the UP and the DOWN conditions, with the latter showing changes for a great extent of the task. Both the UP and the DOWN conditions showed increased COM displacement and velocity. The predominant characteristic during GI on inclined surfaces, including APA, appears to be the displacement of the COM.

Comprehensive quantitative investigation of arm swing during walking at various speed and surface slope conditions

Previous studies have shown that inclusion of arm swing in gait rehabilitation leads to more effective walking recovery in patients with walking impairments. However, little is known about the correct arm-swing trajectories to be used in gait rehabilitation given the fact that changes in walking conditions affect arm-swing patterns. In this paper we present a comprehensive look at the effects of a variety of conditions on arm-swing patterns during walking. The results describe the effects of surface slope, walking speed, and physical characteristics on arm-swing patterns in healthy individuals. We propose data-driven mathematical models to describe arm-swing trajectories. Thirty individuals (fifteen females and fifteen males) with a wide range of height (1.58-1.91m) and body mass (49-98kg), participated in our study. Based on their self-selected walking speed, each participant performed walking trials with four speeds on five surface slopes while their whole-body kinematics were recorded. Statistical analysis showed that walking speed, surface slope, and height were the major factors influencing arm swing during locomotion. The results demonstrate that data-driven models can successfully describe arm-swing trajectories for normal gait under varying walking conditions. The findings also provide insight into the behavior of the elbow during walking.

Spatiotemporal Parameters are not Substantially Influenced by Load Carriage or Inclination During Treadmill and Overground Walking

Influences of load carriage and inclination on spatiotemporal parameters were examined during treadmill and overground walking. Ten soldiers walked on a treadmill and overground with three load conditions (00 kg, 20 kg, 40 kg) during level, uphill (6% grade) and downhill (-6% grade) inclinations at self-selected speed, which was constant across conditions. Mean values and standard deviations for double support percentage, stride length and a step rate were compared across conditions. Double support percentage increased with load and inclination change from uphill to level walking, with a 0.4% stance greater increase at the 20 kg condition compared to 00 kg. As inclination changed from uphill to downhill, the step rate increased more overground (4.3 ± 3.5 steps/min) than during treadmill walking (1.7 ± 2.3 steps/min). For the 40 kg condition, the standard deviations were larger than the 00 kg condition for both the step rate and double support percentage. There was no change between modes for step rate standard deviation. For overground compared to treadmill walking, standard deviation for stride length and double support percentage increased and decreased, respectively. Changes in the load of up to 40 kg, inclination of 6% grade away from the level (i.e., uphill or downhill) and mode (treadmill and overground) produced small, yet statistically significant changes in spatiotemporal parameters. Variability, as assessed by standard deviation, was not systematically lower during treadmill walking compared to overground walking. Due to the small magnitude of changes, treadmill walking appears to replicate the spatiotemporal parameters of overground walking.

Age-related differences when walking downhill on different sloped terrains

Despite the common situation of walking on different sloped terrains, previous work on gait has focused on level terrain. This study aims to assess whether any age-related differences exist in spatiotemporal and stability parameters when walking downhill on three different sloped walkways. Two tri-axial accelerometers were used at the levels of head and pelvis to investigate spatiotemporal parameters, magnitude (root mean square, RMS), harmonic content of accelerations (harmonic ratios, HR) and attenuation between body levels (ATT) in 35 older adults (OA, 69 ± 4.5 y.o.) and 22 young adults (YA, 22.1 ± 1.9 y.o.). Older adults walked at the same speed and cadence as young adults in flat terrain (FL, 0%) and moderate hill (MH, 8%). In the highest slope (PH, 20%), older adults reduced speed and step length and both groups increased cadence. Age had no effect on attenuation and RMS profiles. RMS increased with slope in all directions at both head and pelvis, except, for medio-lateral direction (ML), with similar head RMS in all slopes. There is an important shift in ATT from anteroposterior direction (AP) to ML at the highest slope, resulting in smaller antero-posterior attenuation and greater medio-lateral attenuation. Age differences appeared in the smoothness (HR) at the flat terrain, with increased vertical and antero-posterior values for young adults. As slope increased, group differences disappeared and HR decreased for all directions of motion. In general, spatiotemporal adaptations to increased slope seem to be part of a mechanism to improve ML attenuation, in both young and old adults.

Three-dimensional analysis of foot motion after uphill walking with mobilization with movement using tape applied to the talocrural joint in women with limited ankle dorsiflexion

BACKGROUND

Previous studies that investigated mobilization with movement (MWM) treatment assessed only improvements in passive range of motion (ROM). No information is currently available regarding the efficacy of modified MWM by application of tape. Therefore, we investigated the effect of uphill walking with modified MWM using tape applied to the talocrural joint (uphill walking with MWM taping) in women with limited ankle dorsiflexion.

METHODS

Twelve feet of 12 women with ankle dorsiflexion < 8 degrees were studied. Passive ROM measured using a goniometer was used to select participants. Participants walked on a level walkway under 3 conditions: before exercise, after uphill walking, and after uphill walking with MWM taping. The Oxford Foot Model using 3D motion analysis system was used to examine dynamic foot kinematics, and statistical significance was determined by 1-way repeated-measures analysis of variance.

RESULTS

After uphill walking with MWM taping, peak hindfoot dorsiflexion relative to the tibia was significantly greater than that before exercise and after uphill walking. Furthermore, peak forefoot plantarflexion relative to the hindfoot, peak hindfoot plantarflexion relative to the tibia, and backward tilt of the tibia were greater than those before exercise.

CONCLUSIONS

Uphill walking with MWM taping resulted in an immediate alteration in foot motion during walking, increasing hindfoot dorsiflexion in particular.

CLINICAL RELEVANCE

Further studies are needed to investigate the long-term effects of uphill walking with MWM taping and its potential use in rehabilitation training.