Assessment Of COP Characteristics And Force-Time Changes During Walking In The Third Trimester Of Pregnancy

Purpose: The primary aim of this study was to analyse the COP characteristics and force-time changes during walking between weeks 27 and 36 of pregnancy. The secondary objective was to verify the influence of the specific orthopaedic shoes that were given to the experimental group. This study represents the second part of a research project that processed the same group of pregnant women in order to acquire extended information about gait during pregnancy.Methods: Seventy-three pregnant women participated in this study. This group was random divided into the experimental group (35 pregnant women) wearing specific orthopaedic shoes and the control group (38 pregnant women). The motor task consisted of five gait trials where two foot prints for each leg were always recorded. The participants started barefoot walking 3 m ahead of the pressure platform and finished the trial 1 m after the end of the platform in order to preserve acceleration and deceleration in gait. Participants walked at their own preferred velocity. All pedobarometric parameters were registered by Emed walkway - trademark of novel gmbh in Munich, Germany.Results: The first script processed data to these variables (COP characteristics): Centre of pressure index (COPI), centre of pressure excursion index (COPEI), distance (D) of COP, maximum velocity (MaV) and mean velocity (MeV) of COP. The second script processed data for ten pre-defined areas of the foot: hindfoot, midfoot, MH1-5 – metatarsal heads, big toe, second toe, toes 3, 4 and 5 with these applied variables (force-time characteristics): Force-time integral (FTI) and contact time (CT). For the experimental group, in comparison between 27th week and the 36th week of gestation, we can find lower COPI for both feet, significantly only for the left foot (p=0.04). Also, significant difference in COPEI (p=0.03, p=0.03) for both feet was found. In comparison pre and post measurement we found higher values of parameters COPI and COPEI and that indicates more lateral weight shifting during the last trimester. We can distinctly register extension of D, especially for the left foot (p=0.04). Changes in velocity of COP indicate that MaV was increased for both feet (p=0.00, p=0.00) and MeV was significantly increased only for the right foot (p=0.00) in the 36 week of pregnancy. For the control group, we found no significant changes in COPI, COPEI or COP. MaV and MeV of COP were significantly increased for both feet in the 36 week of pregnancy (p=0.02, p=0.00, p=0.01, p=0.00). Higher values of MaV and MeV indicate that pregnant women accelerated their walking in the 36 week of pregnancy.Further, force-time characteristics in most cases did not reveal statistically significant changes in the last trimester.Conclusion: Over the last three months of pregnancy, significant observable changes can be found, especially through COP parameters of both groups. We found out that the specific orthopaedic shoes given to the experimental group influenced the trajectory of COP, which could have positive health aspects. Further, certain conflicting results of our study in comparison with other similar studies only confirm that individual biomechanic and physiological developments in pregnancy affect the kinematic and kinetic aspects of walking differently.Key Words: Center of pressure, pregnancy, gait, feetPurpose: The primary aim of this study was to analyse the COP characteristics and force-time changes during walking between weeks 27 and 36 of pregnancy. The secondary objective was to verify the influence of the specific orthopaedic shoes that were given to the experimental group. The experimental group wore patented J Hanák R biomechanical footwear and insoles, which are designed to help with redistribution of forces acting the feet, to support both longitudinal and transverse arches of the foot and to strengthen the foot muscles during movement.Methods: Seventy-three pregnant women participated in this study. This group was random divided into the experimental group (35 pregnant women) wearing specific orthopaedic shoes and the control group (38 pregnant women). The motor tasks consisted of five gait trials where two foot impacts for each leg were always recorded. The participants started barefoot walking 3m ahead of the pressure platform and finished the trial 1m after the end of the platform in order to preserve acceleration and deceleration in gait. Participants walked at their own preferred velocity. All pedobarometric parameters were registered by Emed walkway - trademark of novel gmbh in Munich, Germany. Data processing was divided to two scripts. The first script processed data of the variables (COP characteristics): Centre of pressure index (COPI), centre of pressure excursion index (COPEI), distance (D) of COP, maximum velocity (MaV) and mean velocity (MeV) of COP. The second script processed data for ten pre-defined areas of the foot: hindfoot, midfoot, MH1-5 – metatarsal heads, big toe, second toe, toes 3, 4 and 5 with these applied variables (force-time characteristics): Force-time integral (FTI) and contact time (CT).Results: For the experimental group, in comparison between 27th week and the 36th week of gestation, we found lower COPI for both feet, significantly only for the left foot (p=0.04). Also, significant difference in COPEI (p=0.03, p=0.03) for both feet was found. In comparison pre and post measurement we found higher values of parameters COPI and COPEI and that indicates more lateral weight shifting during the last trimester. We can distinctly register extension of D, especially for the left foot (p=0.04). Changes in velocity of COP indicated that MaV was increased for both feet (p=0.00, p=0.00) and MeV was significantly increased only for the right foot (p=0.00) in the 36 week of pregnancy. For the control group, we found no significant changes in COPI, COPEI or COP. MaV and MeV of COP were significantly increased for both feet in the 36th week of pregnancy (p=0.02, p=0.00, p=0.01, p=0.00). Higher values of MaV and MeV indicate that pregnant women accelerated their walking in the 36th week of pregnancy. Further, force-time characteristics in most cases did not reveal statistically significant changes in the last trimester.Conclusion: Over the last three months of pregnancy, significant observable changes can be found, especially through COP parameters of the experimental and the control group. We found out that the specific orthopaedic shoes given to the experimental group influenced the trajectory of COP, which could have positive health aspects. Further, certain conflicting results of our study in comparison with other similar studies only confirm that individual biomechanic and physiological developments in pregnancy affect the kinematic and kinetic aspects of walking differently

Com afecta l’embaràs a les pressions plantars durant la marxa?

Treball Final de Grau de Podologia, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, curs: 2021-2022, Tutor: Carles Vergés SalasDurant el procés de l’embaràs es produeixen canvis fisiològics a nivell psicològic, hormonal i físic. L’augment de pes és un dels esdeveniments que pot fer variar les pressions plantars i provocar compensacions donant lloc a les patologies més freqüents: lumbàlgies i podàlgies. Per mesurar l’evolució de les pressions al llarg de l’embaràs existeixen diferents sistemes com les plataformes de pressions i les plantilles instrumentades. Aquest estudi pretén analitzar la informació publicada sobre la variació de les pressions plantars en dones embarassades i comparar així els seus resultats. S’ha dut a terme una recerca bibliogràfica consultant sis bases de dades i es varen obtenir un total de 12 articles finals segons els criteris d’inclusió i exclusió elegits. Les pressions plantars varien a mesura que avança l’embaràs però no de la mateixa forma entre els diferents estudis. La majoria dels autors defensen que es produeix un augment del PPM al mig peu fruit de l’augment de pes i laxitud dels lligaments, així com l’anteriorització del CdP. Altres autors reporten un augment en l’avantpeu com a estratègia d’absorció d’impacte o al retropeu amb canvis en la morfologia del peu. Els resultats de la magnitud del PPM són molt variats degut a la diferent metodologia dels estudis. Les podàlgies són més freqüents en les dones embarassades però no està relacionat exclusivament amb les variacions de les pressions plantars, sinó que influeixen el CdP, canvis hormonals o l’augment de l’ús d’estructures múscul esquelètiques. Com a conseqüència cada dona embarassada adopta compensacions úniques per garantir una marxa estable

Body mass index and its effect on plantar pressure in overweight and obese adults

The proportion of overweight or obese adults is creating a growing problem throughout the world. Overweight and obesity have a significant influence on gait, and often cause difficulty. There is evidence to suggest that being overweight or obese places adults at a greater risk of developing foot complications such as osteoarthritis, tendonitis, plantar fasciitis, and foot ulcers. Increasingly, pressure ulcers have become a serious health problem. The purpose of this research is to investigate the effect of body weight on the feet, and to investigate the use of simulated body mass to study the effect of variable body mass on the foot plantar in adults aged 24 to 50 years of age while walking at a self-selected pace. A series of studies were undertaken to achieve the above purpose. The research involved: 1) assessing dynamic foot plantar pressure characteristics in adults who are normal weight, overweight or obese; 2) studying the gait impact of increased simulated body weight (SBW); and 3) evaluating the spatial relationship between the trace of the centroid of the area of contact with heel strike, midstance, and toe-off phases for the SBW groups. F-Scan in-shoe systems were utilised to gather the foot pressure data. The first study sought to investigate the effect of different body mass index (BMI) levels on plantar pressure distribution during walking, collection in fifteen voluntary participants were recruited. The BMI participants were divided into three groups (healthy, overweight and obese). The foot was divided into ten regions: heel (H), midfoot (MF), first metatarsal head (1MH), second metatarsal head (2MH), third metatarsal head (3MH), fourth metatarsal head (4MH), fifth metatarsal head (5MH), hallux (1stT), second toe (2ndT), and third to fifth toes (3rd-5thT). For each region, the following parameters were calculated: force (F), contact area (CA), contact pressure (CP), pressure time integral (PTI) and peak pressure (PP). The mean of the three repetitions of each subject was computed, and statistical procedures were performed with these mean ± standard deviation (SD) values. This study showed that the obese group had higher plantar pressure parameter values compared to the other two groups (overweight and healthy) for the ten different foot regions. The study observed significant changes in the parameters in the H and MHs (e.g. 2MH and 3MH) foot regions. The forefoot appears to be more sensitive to weight-related pressure under the foot than the rearfoot. Findings from this study indicate that being overweight or obese increases foot pressure measures, even for individuals with similar body features. Higher BMI values correlate with a higher load on the foot during walking in males. These findings have implications for pain and discomfort in the lower extremity in the obese while participating in activities of daily living such as walking. The second study investigated the effect of the research methodology involving the simulation of body weight (SBW) with additional weight, adding 10, 20, 30 kg to each participant’s body weight on plantar pressures. The sample comprised 31 adult males; each subject walked four times. The first walk was without any external weight (NBW, 0 kg), the second walk was with a weight of 10 kg, the third walk was with a weight of 20 kg and the last walk with a weight of 30 kg in the vest. The foot was divided into ten regions and for each region, the parameters were calculated the same way as the first study. At the end of this study it should be noted that SBW groups subjected to load have shown changes in foot plantar measure values compared to the NBW group. Most of the differences were found under H, MHs, 1stT and MF regions in the most clinically relevant parameters in SBW groups compared to the control group; the SBW groups showed higher values of plantar pressure. The results of the ICC showed a generally good to an excellent level of reliability, the quality of which was dependent on the regions of the foot and the variables investigated with SBW loads. This experiment pointed out that an insole pressure system is a reliable tool for evaluating foot plantar forces and pressures throughout the walk. The plantar pressure measures can be used in relative assessments, as the measures of repeatability are favourable for the measures and foot zones generally utilised in the study of people with clinical problems like neuropathic diabetics. In the final study, associations were investigated of the centroid (coordinates x-axis and y-axis) of the area of contact captured between normal (NBW) and simulated body weight (SBW) changes. The same 31 adult males who enrolled with the SBW tests were used to collect the centroid of the area of contact with the surface. This was located by calculating the geometric centre of a set of cloud points having the lowest z coordinate value. In this part, a foot pressure sensing insole was used to calculate the moment of heel strike, midstance and toe-off phases. Data were analysed descriptively (mean ± SD only). The outcome of this study, relating to specific individual characteristics of the centroid trace of the plantar contact area was compared with the heel strike, midstance, and toe-off phases for the SBW group with the NSBW group. X-axis and y-axis coordinates in the heel strike, midstance and toe-off phases under SBW with 30, 20, 10 kg had higher mean values compared to NSW. The x-axis and y-axis coordinates had mean values of 11.76, 9.68, and 7.76 mm; while the y-axis coordinates had mean values of 11.96, 9.89, and 8.18 mm. Moreover, x-axis and y-axis coordinates were assessed in the midstance phase under SBW with 30, 20, 10 kg with means of 6.59, 5.48, and 4.50 mm; while the y-axis coordinates had mean values of 6.38, 5.41, and 4.41 mm. In addition, x-axis and y-axis coordinates were assessed in the toe-off phase under SBW (30, 20, 10 kg) with mean values of 11.56, 9.67, and 7.97 mm; while the y-axis coordinates had mean values of 11.51, 9.39, 8.02 mm, respectively. X-axis and y-axis coordinates had mean values in relation to NBW in three phases: heel strike of 5.47 and 6.15; midstance of 2.99 and 3.05; and toe-off of 6.04 and 5.82, respectively. The x-locate and y-locate change can be calculate the change in rotation of the ankle joint. As the data was normalised according to the total time taken for the loading phase of the gait, the y-locational change was due partly to the extra weight, which could increase the time of lifting the foot. Therefore, the results showed that the x-locate and y-locate change can help to calculate the change in the rotation of the ankle joint. The project has shown that it is possible to demonstrate that obese people will, throughout their lives, adopt ways to effectively execute a particular activity. This finding provides a foundation for future clinical trials which could assist in preventing foot complications and could assist in the design of appropriate interventions to promote healthy outcomes for these adults. The simulated body weight resulted in a variation in plantar pressure distribution. Because the human foot adapts itself to any simulated condition, knowledge of the variation of pressure distributions of both feet can provide input for suitable guidelines for biomedical engineers. To promote the prevention of likely injury to the feet of overweight and obese people, the results of this study demonstrate the need to develop strategies which could include the building of an insole (orthosis) that absorbs foot plantar pressure

Use of stance control knee-ankle-foot orthoses : a review of the literature

The use of stance control orthotic knee joints are becoming increasingly popular as unlike locked knee-ankle-foot orthoses, these joints allow the limb to swing freely in swing phase while providing stance phase stability, thus aiming to promote a more physiological and energy efficient gait. It is of paramount importance that all aspects of this technology is monitored and evaluated as the demand for evidence based practice and cost effective rehabilitation increases. A robust and thorough literature review was conducted to retrieve all articles which evaluated the use of stance control orthotic knee joints. All relevant databases were searched, including The Knowledge Network, ProQuest, Web of Knowledge, RECAL Legacy, PubMed and Engineering Village. Papers were selected for review if they addressed the use and effectiveness of commercially available stance control orthotic knee joints and included participant(s) trialling the SCKAFO. A total of 11 publications were reviewed and the following questions were developed and answered according to the best available evidence: 1. The effect SCKAFO (stance control knee-ankle-foot orthoses) systems have on kinetic and kinematic gait parameters 2. The effect SCKAFO systems have on the temporal and spatial parameters of gait 3. The effect SCKAFO systems have on the cardiopulmonary and metabolic cost of walking. 4. The effect SCKAFO systems have on muscle power/generation 5. Patient’s perceptions/ compliance of SCKAFO systems Although current research is limited and lacks in methodological quality the evidence available does, on a whole, indicate a positive benefit in the use of SCKAFOs. This is with respect to increased knee flexion during swing phase resulting in sufficient ground clearance, decreased compensatory movements to facilitate swing phase clearance and improved temporal and spatial gait parameters. With the right methodological approach, the benefits of using a SCKAFO system can be evidenced and the research more effectively converted into clinical practice

The effect of prefabricated wrist-hand orthoses on performing activities of daily living

Wrist-hand orthoses (WHOs) are commonly prescribed to manage the functional deficit associated with the wrist as a result of rheumatoid changes. The common presentation of the wrist is one of flexion and radial deviation with ulnar deviation of the fingers. This wrist position Results in altered biomechanics compromising hand function during activities of daily living (ADL). A paucity of evidence exists which suggests that improvements in ADL with WHO use are very task specific. Using normal subjects, and thus in the absence of pain as a limiting factor, the impact of ten WHOs on performing five ADLs tasks was investigated. The tasks were selected to represent common grip patterns and tests were performed with and without WHOs by right-handed, females, aged 20-50 years over a ten week period. The time taken to complete each task was recorded and a wrist goniometer, elbow goniometer and a forearm torsiometer were used to measure joint motion. Results show that, although orthoses may restrict the motion required to perform a task, participants do not use the full range of motion which the orthoses permit. The altered wrist position measured may be attributable to a modified method of performing the task or to a necessary change in grip pattern, resulting in an increased time in task performance. The effect of WHO use on ADL is task specific and may initially impede function. This could have an effect on WHO compliance if there appears to be no immediate benefits. This orthotic effect may be related to restriction of wrist motion or an inability to achieve the necessary grip patterns due to the designs of the orthoses

ASSOCIATION BETWEEN IMU BASED ACCELEROMETRY ON THE TIBIA AND VERTICAL GROUND REACTION FORCE DURING DROP LANDING

Peak vertical ground reaction force is a fundamental biomechanical variable often used to assess lower extremity injury risk. Currently, the tools to measure vGRF are not cost effective. Therefore, the purpose of this study is to determine the association between the variables related to IMU-based accelerometry and vGRF as measured from a research grade force-plate during a drop-landing task. Correlations were run on the averages of the 8 trials for peak vGRF to MVA and MMVAD in the right, left, dominant, and non-dominant limb. The non-dominant limb showed the greatest correlation of peak vGRF to MVA (r=0.803, p<0.01) and MMVAD (r=0.779, p<0.01). The dominant limb showed the lowest correlation of peak vGRF to MVA (r=0.573, p<0.01) and MMVAD (r=0.563, p<0.01). The strength of the association between accelerometry and vGRF during a drop landing may be limb dependent. The strongest associations between vGRF, MVA and MMVAD were in the non-dominant limb.Master of Art

The effect of prefabricated wrist-hand orthoses on grip strength

Prefabricated wrist-hand orthoses (WHOs) are commonly prescribed to manage the functional deficit and compromised grip strength as a result of rheumatoid changes. It is thought that an orthosis which improves wrist extension, reduces synovitis and increases the mechanical advantage of the flexor muscles will improve hand function. Previous studies report an initial reduction in grip strength with WHO use which may increase following prolonged use. Using normal subjects, and thus in the absence of pain as a limiting factor, the impact of ten WHOs on grip strength was measured using a Jamar dynamometer. Tests were performed with and without WHOs by right-handed, female subjects, aged 20-50 years over a ten week period. During each test, a wrist goniometer and a forearm torsiometer were used to measure wrist joint position when maximum grip strength was achieved. The majority of participants achieved maximum grip strength with no orthosis at 30° extension. All the orthoses reduced initial grip strength but surprisingly the restriction of wrist extension did not appear to contribute in a significant way to this. Reduction in grip must therefore also be attributable to WHO design characteristics or the quality of fit. The authors recognize the need for research into the long term effect of WHOs on grip strength. However if grip is initially adversely affected, patients may be unlikely to persevere with treatment thereby negating all therapeutic benefits. In studies investigating patient opinions on WHO use, it was a stable wrist rather than a stronger grip reported to have facilitated task performance. This may explain why orthoses that interfere with maximum grip strength can improve functional task performance. Therefore while it is important to measure grip strength, it is only one factor to be considered when evaluating the efficacy of WHOs