1
|
Holmes PD, Danforth SM, Fu XY, Moore TY, Vasudevan R. Characterizing the limits of human stability during motion: perturbative experiment validates a model-based approach for the Sit-to-Stand task. ROYAL SOCIETY OPEN SCIENCE 2020; 7:191410. [PMID: 32218959 PMCID: PMC7029948 DOI: 10.1098/rsos.191410] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 11/26/2019] [Indexed: 06/10/2023]
Abstract
Falls affect a growing number of the population each year. Clinical methods to assess fall risk usually evaluate the performance of specific motions such as balancing or Sit-to-Stand. Unfortunately, these techniques have been shown to have poor predictive power, and are unable to identify the portions of motion that are most unstable. To this end, it may be useful to identify the set of body configurations that can accomplish a task under a specified control strategy. The resulting strategy-specific boundary between stable and unstable motion could be used to identify individuals at risk of falling. The recently proposed Stability Basin is defined as the set of configurations through time that do not lead to failure for an individual under their chosen control strategy. This paper presents a novel method to compute the Stability Basin and the first experimental validation of the Stability Basin with a perturbative Sit-to-Stand experiment involving forwards or backwards pulls from a motor-driven cable with 11 subjects. The individually-constructed Stability Basins are used to identify when a trial fails, i.e. when an individual must switch from their chosen control strategy (indicated by a step or sit) to recover from a perturbation. The constructed Stability Basins correctly predict the outcome of trials where failure was observed with over 90 % accuracy, and correctly predict the outcome of successful trials with over 95 % accuracy. The Stability Basin was compared to three other methods and was found to estimate the stable region with over 45 % more accuracy in all cases. This study demonstrates that Stability Basins offer a novel model-based approach for quantifying stability during motion, which could be used in physical therapy for individuals at risk of falling.
Collapse
Affiliation(s)
- Patrick D. Holmes
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Shannon M. Danforth
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Xiao-Yu Fu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Talia Y. Moore
- Robotics Institute, University of Michigan, Ann Arbor, MI, USA
| | - Ram Vasudevan
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA
- Robotics Institute, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
2
|
Inai T, Takabayashi T, Edama M, Kubo M. Relationship between movement time and hip moment impulse in the sagittal plane during sit-to-stand movement: a combined experimental and computer simulation study. Biomed Eng Online 2018; 17:48. [PMID: 29703194 PMCID: PMC5923195 DOI: 10.1186/s12938-018-0486-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 04/23/2018] [Indexed: 11/18/2022] Open
Abstract
Background The association between repetitive hip moment impulse and the progression of hip osteoarthritis is a recently recognized area of study. A sit-to-stand movement is essential for daily life and requires hip extension moment. Although a change in the sit-to-stand movement time may influence the hip moment impulse in the sagittal plane, this effect has not been examined. The purpose of this study was to clarify the relationship between sit-to-stand movement time and hip moment impulse in the sagittal plane. Methods Twenty subjects performed the sit-to-stand movement at a self-selected natural speed. The hip, knee, and ankle joint angles obtained from experimental trials were used to perform two computer simulations. In the first simulation, the actual sit-to-stand movement time obtained from the experiment was entered. In the second simulation, sit-to-stand movement times ranging from 0.5 to 4.0 s at intervals of 0.25 s were entered. Hip joint moments and hip moment impulses in the sagittal plane during sit-to-stand movements were calculated for both computer simulations. Results and conclusions The reliability of the simulation model was confirmed, as indicated by the similarities in the hip joint moment waveforms (r = 0.99) and the hip moment impulses in the sagittal plane between the first computer simulation and the experiment. In the second computer simulation, the hip moment impulse in the sagittal plane decreased with a decrease in the sit-to-stand movement time, although the peak hip extension moment increased with a decrease in the movement time. These findings clarify the association between the sit-to-stand movement time and hip moment impulse in the sagittal plane and may contribute to the prevention of the progression of hip osteoarthritis.
Collapse
Affiliation(s)
- Takuma Inai
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata, Niigata, 950-3198, Japan. .,Department of Rehabilitation, Oguma Orthopedics Clinic, 5-8-9 Koshin, Nishi-ku, Niigata, Niigata, 950-2023, Japan.
| | - Tomoya Takabayashi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata, Niigata, 950-3198, Japan
| | - Mutsuaki Edama
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata, Niigata, 950-3198, Japan
| | - Masayoshi Kubo
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata, Niigata, 950-3198, Japan
| |
Collapse
|
3
|
Matthew RP, Shia V, Venture G, Bajcsy R. Generating physically realistic kinematic and dynamic models from small data sets: An application for sit-to-stand actions. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2016:2173-2178. [PMID: 28268763 DOI: 10.1109/embc.2016.7591160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Kinematic and dynamic models are used to create simplified, yet accurate representations of reality. In application to biological systems, there is often a choice on what level of complexity is appropriate for the model. This paper introduces a structured method for obtaining an accurate model that can represent the sit-to-stand motion and reproduce the associated contact forces in the standing phase. These models are generated from small datasets, just five measured sit-to-stand actions, and result in simple, physically realisable dynamic models. The assumptions made apriori on the model are minimal, with the number of segments, axes of rotation, marker allocation and location, and dynamic model all determined from this small dataset. From this initial analysis, the use of a triple pendulum with a simple point mass at the centre of the torso was found to be representative. Through the generation of these simple, repeatable models, this work aims to develop a modelling framework that is suitable for the study of biological systems and clinical use.
Collapse
|
4
|
Letchford R, Button K, Adamson P, Roos PE, Sparkes V, van Deursen RWM. A novel clinical approach for assessing hop landing strategies: a 2D telescopic inverted pendulum (TIP) model. Knee Surg Sports Traumatol Arthrosc 2016; 24:279-86. [PMID: 25315084 DOI: 10.1007/s00167-014-3378-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 10/07/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE Single leg hop for distance is used to inform rehabilitation and return to sport following anterior cruciate ligament reconstruction. However, impairment of landing mechanics may persist after the recommended performance parameter (hop distance) has been met; therefore, alternative methods are required. This study follows the COSMIN guideline to investigate the measurement properties of data from a new instrument (2D TIP). This is a simple motion analysis instrument to assess landing strategy based on more complex biomechanical modelling. METHODS Data collected in the clinical setting from 30 subjects with chronic ACL deficiency (mean 15.5, SD 4.3 months following injury) before and 6 months after ACL reconstruction and a healthy control group were analysed. Reliability and measurement error were calculated using two repeated measures from three independent raters. Construct validity was assessed by hypothesis testing, and known groups validity and responsiveness were defined by differences between groups. RESULTS The data demonstrate excellent inter-rater (ICC = 0.81-1.00) and intra-rater (ICC = 0.85-1.00) reliability with low measurement error. Of the eight construct validity hypothesis, six were fully and two partially supported. Between-group differences were significant (P < 0.05) supporting the validity and responsiveness hypothesis. CONCLUSION 2D TIP is a simple and inexpensive instrument for assessing landing strategy that has demonstrated appropriate reliability, validity and responsiveness in the ACL-injured population. The instrument will now be used to identify altered movement strategies and develop novel rehabilitation interventions that target strategy and performance. LEVEL OF EVIDENCE Prospective diagnostic study, Level II.
Collapse
Affiliation(s)
- Robert Letchford
- School of Healthcare Sciences, Cardiff University, Second Floor, Cardigan House, Heath Park Campus, Cardiff, CF14 4XN, UK. .,Aneurin Bevan Health Board, Physiotherapy Department, Royal Gwent Hospital, Cardiff Road, Newport, Gwent, NP20 2UB, UK.
| | - Kate Button
- School of Healthcare Sciences, Cardiff University, Second Floor, Cardigan House, Heath Park Campus, Cardiff, CF14 4XN, UK.,Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK.,Cardiff and Vale University Health Board, Physiotherapy Department, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, UK
| | - Paul Adamson
- School of Healthcare Sciences, Cardiff University, Second Floor, Cardigan House, Heath Park Campus, Cardiff, CF14 4XN, UK.,Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK.,Cardiff and Vale University Health Board, Physiotherapy Department, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, UK
| | - Paulien E Roos
- School of Healthcare Sciences, Cardiff University, Second Floor, Cardigan House, Heath Park Campus, Cardiff, CF14 4XN, UK.,Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK
| | - Valerie Sparkes
- School of Healthcare Sciences, Cardiff University, Second Floor, Cardigan House, Heath Park Campus, Cardiff, CF14 4XN, UK.,Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK
| | - Robert W M van Deursen
- School of Healthcare Sciences, Cardiff University, Second Floor, Cardigan House, Heath Park Campus, Cardiff, CF14 4XN, UK.,Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK
| |
Collapse
|
5
|
bin Ghazali MZ, Miskon MF, bin Ali F, bin Bahar MB. Investigating the relationship between TIP and 3-link models when the links' length are varied. 2015 IEEE INTERNATIONAL SYMPOSIUM ON ROBOTICS AND INTELLIGENT SENSORS (IRIS) 2015. [DOI: 10.1109/iris.2015.7451612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
|
6
|
bin Ghazali MZ, Miskon MF, bin Ali F, bin Bahar MB. Investigating the relationship between TIP and three-link models when the mass are varied. 2015 IEEE INTERNATIONAL SYMPOSIUM ON ROBOTICS AND INTELLIGENT SENSORS (IRIS) 2015. [DOI: 10.1109/iris.2015.7451611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
|
7
|
Bouchouras G, Patsika G, Hatzitaki V, Kellis E. Kinematics and knee muscle activation during sit-to-stand movement in women with knee osteoarthritis. Clin Biomech (Bristol, Avon) 2015; 30:599-607. [PMID: 25846323 DOI: 10.1016/j.clinbiomech.2015.03.025] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 03/24/2015] [Accepted: 03/24/2015] [Indexed: 02/07/2023]
Abstract
BACKROUND The purpose of this study was to compare joint kinematics, knee and trunk muscle activation and co-activation patterns during a sit-to-stand movement in women with knee osteoarthritis and age-matched controls. METHODS Eleven women with knee osteoarthritis (mean and standard deviation, age: 66.90, 4.51 years, height: 1.63, 0.02 m, mass: 77.63, 5.4 kg) and eleven healthy women (mean and standard deviation, age: 61.90, 3.12 years, height: 1.63 m, 0.03, mass: 78.30, 4.91 kg) performed a Sit to Stand movement at a self-selected slow, normal and fast speed. Three-dimensional joint kinematics of the lower limb, vertical ground reaction forces and electromyographic activity of the biceps femoris vastus lateralis and erectus spinae were recorded bilaterally. FINDINGS A two-way ANOVA showed that the osteoarhtitis group performed the sit to stand task using a smaller knee and hip range of motion compared with the control group while no differences in temporal kinematics and ground reaction force-related parameters were observed. In addition, women with osteoarhtritis displayed significantly lower vastus lateralis coupled with a higher biceps feomoris electromyographic activity and higher agonist-antagonist co-contraction and co-activation than asymptomatic women. The activation of erectus spinae was not different between groups. INTERPRETATION Results indicate that patients with moderate knee osteoarthritis rise from the chair using greater knee muscle co-contraction, earlier and greater activation of the hamstrings which results in reduced hip and knee range of motion. This may be a way to overcome the pain and potential muscle atrophy of knee extensor muscles without compromising overall task duration.
Collapse
Affiliation(s)
- Georgios Bouchouras
- Motor Control and Learning Laboratory, Faculty of Physical Education and Sport Sciences, Aristotle University of Thessaloniki, Greece.
| | - Glykeria Patsika
- Laboratory of Neuromechanics, Faculty of Physical Education and Sport Sciences, Aristotle University of Thessaloniki, Greece
| | - Vassilia Hatzitaki
- Motor Control and Learning Laboratory, Faculty of Physical Education and Sport Sciences, Aristotle University of Thessaloniki, Greece
| | - Eleftherios Kellis
- Laboratory of Neuromechanics, Department of Physical Education and Sports Science of Serres, Aristotle University of Thessaloniki, Greece
| |
Collapse
|
8
|
Weaver TB, Glinka MN, Laing AC. Moving beyond quiet stance: applicability of the inverted pendulum model to stooping and crouching postures. J Biomech 2014; 47:3574-9. [PMID: 25262878 DOI: 10.1016/j.jbiomech.2014.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 08/28/2014] [Accepted: 09/03/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Currently, it is unknown whether the inverted pendulum model is applicable to stooping or crouching postures. Therefore, the aim of this study was to determine the degree of applicability of the inverted pendulum model to these postures, via examination of the relationship between the centre of mass (COM) acceleration and centre of pressure (COP)-COM difference. METHODS Ten young adults held static standing, stooping and crouching postures, each for 20s. For both the anterior-posterior (AP) and medio-lateral (ML) directions, the time-varying COM acceleration and the COP-COM were computed, and the relationship between these two variables was determined using Pearson's correlation coefficients. Additionally, in both directions, the average absolute COM acceleration, average absolute COP-COM signal, and the inertial component (i.e., -I/Wh) were compared across postures. RESULTS Pearson correlation coefficients revealed a significant negative relationship between the COM acceleration and COP-COM signal for all comparisons, regardless of the direction (p<0.001). While no effect of posture was observed in the AP direction (p=0.463), in the ML direction, the correlation coefficients for stooping were different (i.e., stronger) than standing (p=0.008). Regardless of direction, the average absolute COM acceleration for both the stooping and crouching postures was greater than standing (p<0.002). CONCLUSION The high correlations indicate that the inverted pendulum model is applicable to stooping and crouching postures. Due to their importance in completing activities of daily living, there is merit in determining what type of motor strategies are used to control such postures and whether these strategies change with age.
Collapse
Affiliation(s)
- Tyler B Weaver
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Michal N Glinka
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Andrew C Laing
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.
| |
Collapse
|
9
|
Roos PE, Button K, Sparkes V, van Deursen RWM. Altered biomechanical strategies and medio-lateral control of the knee represent incomplete recovery of individuals with injury during single leg hop. J Biomech 2013; 47:675-80. [PMID: 24342500 PMCID: PMC3968881 DOI: 10.1016/j.jbiomech.2013.11.046] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 11/01/2013] [Accepted: 11/24/2013] [Indexed: 01/12/2023]
Abstract
Anterior cruciate ligament (ACL) injury can result in failure to return to pre-injury activity levels and future osteoarthritis predisposition. Single leg hop is used in late rehabilitation to evaluate recovery and inform treatment but biomechanical understanding of this activity is insufficient. This study investigated single leg hop for distance aiming to evaluate if ACL patients had recovered: (1) landing strategies and (2) medio-lateral knee control. We hypothesized that patients with reconstructive surgery (ACLR) would have more similar landing strategies and knee control to healthy controls than patients treated conservatively (ACLD). 16 ACLD and 23 ACLR subjects were compared to 20 healthy controls (CONT). Kinematic and ground reaction force data were collected while subjects hopped their maximum distance. The main output parameters were hop distance, peak knee flexor angles and extensor moments and Fluency (a measure introduced to represent medio-lateral knee control). Statistical differences between ACL and control groups were analyzed using a general linear model univariate analysis, with COM velocity prior to landing as covariate. Hop distance was the smallest for ACLD and largest for CONT (p<0.001; ACLD 57.1±14.1; ACLR 75.1±17.8; CONT 77.7±14.07% height). ACLR used a similar kinematic strategy to CONT, but had a reduced peak knee extensor moment (p<0.001; ACLD 0.32±0.14; ACLR 0.31±0.16; CONT 0.42±0.13 BW.height). Fluency was reduced in both ACLD and ACLR (p=0.006; ACLD 0.13±0.34; ACLR 0.14±0.34; CONT 0.17±0.41 s). Clinical practice uses hopping distance to evaluate ACL patients' recovery. This study demonstrated that aspects such as movement strategies and knee control need to be evaluated.
Collapse
Affiliation(s)
- Paulien E Roos
- School of Healthcare Sciences, Cardiff University, Cardiff CF14 4XN, UK; Arthritis Research UK Biomechanics and Bioengineering Centre, Division School of Healthcare Sciences, Cardiff University, Cardiff CF14 4XN, UK.
| | - Kate Button
- School of Healthcare Sciences, Cardiff University, Cardiff CF14 4XN, UK; Arthritis Research UK Biomechanics and Bioengineering Centre, Division School of Healthcare Sciences, Cardiff University, Cardiff CF14 4XN, UK; Cardiff and Vale University Health Board, Cardiff, UK
| | - Valerie Sparkes
- School of Healthcare Sciences, Cardiff University, Cardiff CF14 4XN, UK; Arthritis Research UK Biomechanics and Bioengineering Centre, Division School of Healthcare Sciences, Cardiff University, Cardiff CF14 4XN, UK
| | - Robert W M van Deursen
- School of Healthcare Sciences, Cardiff University, Cardiff CF14 4XN, UK; Arthritis Research UK Biomechanics and Bioengineering Centre, Division School of Healthcare Sciences, Cardiff University, Cardiff CF14 4XN, UK
| |
Collapse
|
10
|
Region of stability derived by center of mass acceleration better identifies individuals with difficulty in sit-to-stand movement. Ann Biomed Eng 2013; 42:733-41. [PMID: 24259008 DOI: 10.1007/s10439-013-0945-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 11/14/2013] [Indexed: 10/26/2022]
Abstract
Poor performance of sit-to-stand (STS) has been identified as one of the predictors of fall risk among elderly adults. This study examined differences in the whole body center of mass (COM) kinematic variables in relation to the regions of stability between elderly adults with difficulty in STS and healthy individuals. Whole body motion data while performing STS were collected from 10 young, 10 elderly and 10 elderly subjects with difficulty in STS. Young subjects were also asked to stand up with their trunk purposely bent forward. The regions of stability were defined with COM position at seat-off and its instantaneous velocity (ROSv) or peak acceleration (ROSa), using a single-link-plus-foot inverted pendulum model. Peak COM accelerations prior to seat-off differed significantly among groups; however, no significant differences were detected in its velocities at seat-off. The ROSa demonstrated a better ability to discriminate elderly adults with difficulty from healthy individuals. Although a similar COM momentum was observed at seat-off, how the momentum was controlled differed between healthy individuals and individuals with difficulty in STS. ROSa could provide insight into how the COM momentum is controlled prior to seat-off, which could be used to differentiate individuals with functional limitations from healthy individuals.
Collapse
|
11
|
Experimental evaluation of balance prediction models for sit-to-stand movement in the sagittal plane. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2013; 2013:592328. [PMID: 24187580 PMCID: PMC3804152 DOI: 10.1155/2013/592328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Revised: 09/04/2013] [Accepted: 09/05/2013] [Indexed: 12/02/2022]
Abstract
Evaluation of balance control ability would become important in the rehabilitation training. In this paper, in order to make clear usefulness and limitation of a traditional simple inverted pendulum model in balance prediction in sit-to-stand movements, the traditional simple model was compared to an inertia (rotational radius) variable inverted pendulum model including multiple-joint influence in the balance predictions. The predictions were tested upon experimentation with six healthy subjects. The evaluation showed that the multiple-joint influence model is more accurate in predicting balance under demanding sit-to-stand conditions. On the other hand, the evaluation also showed that the traditionally used simple inverted pendulum model is still reliable in predicting balance during sit-to-stand movement under non-demanding (normal) condition. Especially, the simple model was shown to be effective for sit-to-stand movements with low center of mass velocity at the seat-off. Moreover, almost all trajectories under the normal condition seemed to follow the same control strategy, in which the subjects used extra energy than the minimum one necessary for standing up. This suggests that the safety considerations come first than the energy efficiency considerations during a sit to stand, since the most energy efficient trajectory is close to the backward fall boundary.
Collapse
|
12
|
van Lummel RC, Ainsworth E, Hausdorff JM, Lindemann U, Beek PJ, van Dieën JH. Validation of seat-off and seat-on in repeated sit-to-stand movements using a single-body-fixed sensor. Physiol Meas 2012; 33:1855-67. [DOI: 10.1088/0967-3334/33/11/1855] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
13
|
Fuschillo VL, Bagalà F, Chiari L, Cappello A. Accelerometry-based prediction of movement dynamics for balance monitoring. Med Biol Eng Comput 2012; 50:925-36. [PMID: 22802142 DOI: 10.1007/s11517-012-0940-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 07/03/2012] [Indexed: 11/24/2022]
Abstract
This paper proposes a 2D functional evaluation tool for estimating subject-specific body segment parameters, which uses a simple motor task (repeated sit-to-stand, rSTS), recorded with one single-axis accelerometer (SAA) per segment and a force plate (FP). After this preliminary estimation, the accelerometer alone is used to make quasi-real-time predictions of ground reaction force (anterior/posterior, F ( X ), and vertical, F ( Z ), components), center of pressure (CoP) and center of mass (CoM), during rSTS and postural oscillation in the sagittal plane. These predicted dynamic variables, as well as those obtained using anthropometric parameters derived from De Leva, were compared to actual FP outputs in terms of root mean-squared errors (RMSEs). Using De Leva's parameters in place of those estimated, RMSEs increase from 12 to 21 N (F ( X )), from 21 to 24 N (F ( Z )), and from 21.1 to 55.6 mm (CoP) in rSTS; similarly, RMSEs increase from 3.1 to 3.3 N (F ( X )) and from 5.5 to 6.6 mm (CoP) in oscillatory trials. A telescopic inverted pendulum model was adopted to analyze the balance control in rSTS using only predicted CoP and CoM. Results suggest that one SAA per segment is sufficient to predict the dynamics of a biomechanical model of any degrees of freedom.
Collapse
Affiliation(s)
- Valeria Lucia Fuschillo
- Department of Electronics, Computer Science and Systems (DEIS), University of Bologna, Bologna, Italy.
| | | | | | | |
Collapse
|
14
|
Roos PE, Barton N, van Deursen RWM. Patellofemoral joint compression forces in backward and forward running. J Biomech 2012; 45:1656-60. [PMID: 22503882 PMCID: PMC3391667 DOI: 10.1016/j.jbiomech.2012.03.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 03/22/2012] [Accepted: 03/23/2012] [Indexed: 11/19/2022]
Abstract
Patellofemoral pain (PFP) is a common injury and increased patellofemoral joint compression forces (PFJCF) may aggravate symptoms. Backward running (BR) has been suggested for exercise with reduced PFJCF. The aims of this study were to (1) investigate if BR had reduced peak PFJCF compared to forward running (FR) at the same speed, and (2) if PFJCF was reduced in BR, to investigate which biomechanical parameters explained this. It was hypothesized that (1) PFJCF would be lower in BR, and (2) that this would coincide with a reduced peak knee moment caused by altered ground reaction forces (GRFs). Twenty healthy subjects ran in forward and backward directions at consistent speed. Kinematic and ground reaction force data were collected; inverse dynamic and PFJCF analyses were performed. PFJCF were higher in FR than BR (4.5±1.5; 3.4±1.4BW; p<0.01). The majority of this difference (93.1%) was predicted by increased knee moments in FR compared to BR (157±54; 124±51 Nm; p<0.01). 54.8% of differences in knee moments could be predicted by the magnitude of the GRF (2.3±0.3; 2.4±0.2BW), knee flexion angle (44±6; 41±7) and center of pressure location on the foot (25±11; 12±6%) at time of peak knee moment. Results were not consistent in all subjects. It was concluded that BR had reduced PFJCF compared to FR. This was caused by an increased knee moment, due to differences in magnitude and location of the GRF vector relative to the knee. BR can therefore be used to exercise with decreased PFJCF.
Collapse
Affiliation(s)
- Paulien E Roos
- Department of Physiotherapy, School of Healthcare Studies, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.
| | | | | |
Collapse
|
15
|
Tsukahara A, Kawanishi R, Hasegawa Y, Sankai Y. Sit-to-Stand and Stand-to-Sit Transfer Support for Complete Paraplegic Patients with Robot Suit HAL. Adv Robot 2012. [DOI: 10.1163/016918610x512622] [Citation(s) in RCA: 194] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Atsushi Tsukahara
- a Systems and Information Engineering, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan
| | - Ryota Kawanishi
- b Systems and Information Engineering, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan
| | - Yasuhisa Hasegawa
- c Systems and Information Engineering, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan
| | - Yoshiyuki Sankai
- d Systems and Information Engineering, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan
| |
Collapse
|
16
|
Fujimoto M, Chou LS. Dynamic balance control during sit-to-stand movement: An examination with the center of mass acceleration. J Biomech 2012; 45:543-8. [DOI: 10.1016/j.jbiomech.2011.11.037] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 11/10/2011] [Accepted: 11/16/2011] [Indexed: 10/14/2022]
|
17
|
Conjugate momentum estimate using non-linear dynamic model of the sit-to-stand correlates well with accelerometric surface data. J Biomech 2011; 44:1073-7. [DOI: 10.1016/j.jbiomech.2011.01.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 01/29/2011] [Accepted: 01/31/2011] [Indexed: 11/17/2022]
|
18
|
Vannozzi G, Pecoraro F, Caserotti P, Cappozzo A. A neurofuzzy inference system based on biomechanical features for the evaluation of the effects of physical training. Comput Methods Biomech Biomed Engin 2008; 11:11-7. [DOI: 10.1080/10255840701550915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
19
|
Vannozzi G, Cereatti A, Mazzà C, Benvenuti F, Della Croce U. Extraction of information on elder motor ability from clinical and biomechanical data through data mining. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2007; 88:85-94. [PMID: 17719673 DOI: 10.1016/j.cmpb.2007.07.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2007] [Revised: 07/11/2007] [Accepted: 07/12/2007] [Indexed: 05/16/2023]
Abstract
This study aimed at evaluating the additional knowledge provided by a biomechanical test coupled with clinical tests for motor ability assessment. A database including clinical test scores and sit-to-stand test variables obtained from 110 medically stable elderly subjects was submitted to data mining by searching for association rules. The presence of rules revealed some redundancies due to sample homogeneity, as mainly observed in the joint analysis of a questionnaire for daily activities assessment (Nottingham test) and the sit-to-stand, and due to similar evaluated information, as resulted from the joint analysis of a balance and gait scale (Tinetti test) and the sit-to-stand. Conversely, when no association rules were found, the tests carried unrelated information. The associations mined while analysing these clinical tests encouraged the integration of biomechanical tests, increasing significantly its clinical applicability and reducing the information redundancy. The information extracted also allowed to highlight rules typical of elderly persons that may serve as a knowledge-based tool for the detection of possible deviation from normality.
Collapse
Affiliation(s)
- G Vannozzi
- Department of Human Movement and Sport Sciences, Istituto Universitario di Scienze Motorie, Roma, Italy.
| | | | | | | | | |
Collapse
|
20
|
Mazzà C, Stanhope SJ, Taviani A, Cappozzo A. Biomechanic Modeling of Sit-to-Stand to Upright Posture for Mobility Assessment of Persons With Chronic Stroke. Arch Phys Med Rehabil 2006; 87:635-41. [PMID: 16635625 DOI: 10.1016/j.apmr.2005.12.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Accepted: 12/22/2005] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To test the suitability of using biomechanic measures associated with a minimum measured input model (MMIM) approach to assess mobility of people with chronic stroke during the execution of a sit-to-stand (STS) to upright posture motor task. DESIGN Single group, observational. SETTING Institutional settings in the United States and Italy. PARTICIPANTS Twenty-nine subjects with chronic unilateral lower-limb impairments and resultant mobility limitations secondary to stroke. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Manual measurement of lower-limb strength; performance-based tests including repeated chair standing, walking speed, and standing balance; and ground reactions measured with a force platform during STS and upright posture. The ground reactions were fed to a telescopic inverted pendulum model of the musculoskeletal system. Parameters representing the model outputs were compared with performance-based and strength measures to assess, respectively, motor ability and impairment-related changes in subjects' motor strategies. RESULTS The parameters derived from the model effectively differentiated between motor strategies associated with different performance-based scores, and allowed the identification of relevant difficulties encountered in STS execution. These difficulties could be associated with different strength scores. This was also true for subjects scoring the maximum in both performance-based and strength tests. CONCLUSIONS The MMIM is a relatively inexpensive and noninvasive approach that enhances mobility assessment of hemiparetic subjects with different motor ability levels. It provides information that correlates well with performance-based and strength scores and, in addition, it allows for subject-specific motor strategy identification.
Collapse
Affiliation(s)
- Claudia Mazzà
- Department of Human Movement and Sport Sciences, Istituto Universitario di Scienze Motorie, Rome, Italy.
| | | | | | | |
Collapse
|
21
|
Mazzà C, Zok M, Della Croce U. Sequencing sit-to-stand and upright posture for mobility limitation assessment: determination of the timing of the task phases from force platform data. Gait Posture 2005; 21:425-31. [PMID: 15886132 DOI: 10.1016/j.gaitpost.2004.05.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2003] [Accepted: 05/17/2004] [Indexed: 02/02/2023]
Abstract
The identification of quantitative tools to assess an individual's mobility limitation is a complex and challenging task. Several motor tasks have been designated as potential indicators of mobility limitation. In this study, a multiple motor task obtained by sequencing sit-to-stand and upright posture was used. Algorithms based on data obtained exclusively from a single force platform were developed to detect the timing of the motor task phases (sit-to-stand, preparation to the upright posture and upright posture). To test these algorithms, an experimental protocol inducing predictable changes in the acquired signals was designed. Twenty-two young, able-bodied subjects performed the task in four different conditions: self-selected natural and high speed with feet kept together, and self-selected natural and high speed with feet pelvis-width apart. The proposed algorithms effectively detected the timing of the task phases, the duration of which was sensitive to the four different experimental conditions. As expected, the duration of the sit-to-stand was sensitive to the speed of the task and not to the foot position, while the duration of the preparation to the upright posture was sensitive to foot position but not to speed. In addition to providing a simple and effective description of the execution of the motor task, the correct timing of the studied multiple task could facilitate the accurate determination of variables descriptive of the single isolated phases, allowing for a more thorough description of the motor task and therefore could contribute to the development of effective quantitative functional evaluation tests.
Collapse
Affiliation(s)
- Claudia Mazzà
- Dipartimento di Scienze del Movimento Umano e dello Sport, Istituto Universitario di Scienze Motorie, Piazza Lauro de Bosis 6, 00194 Roma, Italy.
| | | | | |
Collapse
|
22
|
Cappozzo * A, Camomilla V, Della Croce U, Mazzà C, Quagliarella L, Vannozzi G, Zok M. Musculoskeletal system modelling for the evaluation of motor disability. THEORETICAL ISSUES IN ERGONOMICS SCIENCE 2005. [DOI: 10.1080/14639220412331329654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
23
|
Mazzà C, Benvenuti F, Bimbi C, Stanhope SJ. Association between subject functional status, seat height, and movement strategy in sit-to-stand performance. J Am Geriatr Soc 2004; 52:1750-4. [PMID: 15450056 DOI: 10.1111/j.1532-5415.2004.52472.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To explore the association between an individual's functional status, movement task difficulty, and effectiveness of compensatory movement strategies within a sit-to-stand (STS) paradigm. DESIGN Cross-sectional study. SETTINGS Rehabilitation unit of the Istituto Nazionale Riposo e Cura Anziani Geriatric Hospital of Florence, Italy. PARTICIPANTS A convenience sample (131 subjects) of the outpatient clinic and day-hospital population. MEASUREMENTS A performance-based test (repeated chair standing) was used to divide the subjects into five functional groups. Subjects performed a series of single STS tasks across a range of five descending seat heights. They were instructed to stand without using arms or compensatory strategies. If unable, swinging the arms was allowed, and if the inability persisted, subjects could push with their arms during subsequent attempts. The strategy or inability to stand formed the dependent measures. RESULTS Subjects within the two highest functional groups could complete the single STS task at all seat heights, with a slight increased use of compensatory strategies at the lowest seat height. The effectiveness of the compensatory strategies decreased rapidly as a function of seat height and functional status. One-third (35.5%) of the subjects in the middle functional group swung their arms at the lower seat heights. Across the three least functional groups, 11.8%, 30.6%, and 83.3% of the subjects, respectively, were unable to stand at the lowest seat height. CONCLUSION The individual's functional status and difficulty of the task influenced the effectiveness of a compensatory strategy to maintain the ability to stand, supporting the idea that disability depends on the interplay between environmental demands and physical ability.
Collapse
Affiliation(s)
- Claudia Mazzà
- Department of Human Movement and Sport Sciences, Istituto Universitario di Scienze Motorie, Rome, Italy
| | | | | | | |
Collapse
|
24
|
Vannozzi G, Della Croce U, Starita A, Benvenuti F, Cappozzo A. Knowledge discovery in databases of biomechanical variables: application to the sit to stand motor task. J Neuroeng Rehabil 2004; 1:7. [PMID: 15679936 PMCID: PMC546397 DOI: 10.1186/1743-0003-1-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Accepted: 10/29/2004] [Indexed: 11/10/2022] Open
Abstract
ABSTRACT : BACKGROUND : The interpretation of data obtained in a movement analysis laboratory is a crucial issue in clinical contexts. Collection of such data in large databases might encourage the use of modern techniques of data mining to discover additional knowledge with automated methods. In order to maximise the size of the database, simple and low-cost experimental set-ups are preferable. The aim of this study was to extract knowledge inherent in the sit-to-stand task as performed by healthy adults, by searching relationships among measured and estimated biomechanical quantities. An automated method was applied to a large amount of data stored in a database. The sit-to-stand motor task was already shown to be adequate for determining the level of individual motor ability. METHODS : The technique of search for association rules was chosen to discover patterns as part of a Knowledge Discovery in Databases (KDD) process applied to a sit-to-stand motor task observed with a simple experimental set-up and analysed by means of a minimum measured input model. Selected parameters and variables of a database containing data from 110 healthy adults, of both genders and of a large range of age, performing the task were considered in the analysis. RESULTS : A set of rules and definitions were found characterising the patterns shared by the investigated subjects. Time events of the task turned out to be highly interdependent at least in their average values, showing a high level of repeatability of the timing of the performance of the task. CONCLUSIONS : The distinctive patterns of the sit-to-stand task found in this study, associated to those that could be found in similar studies focusing on subjects with pathologies, could be used as a reference for the functional evaluation of specific subjects performing the sit-to-stand motor task.
Collapse
Affiliation(s)
- Giuseppe Vannozzi
- Department of Human Movement and Sport Sciences, University Institute for Movement Science, Roma
| | - Ugo Della Croce
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | | | | | - Aurelio Cappozzo
- Department of Human Movement and Sport Sciences, University Institute for Movement Science, Roma
| |
Collapse
|
25
|
Abstract
Abstract
Background and Purpose. The sit-to-stand (STS) movement is a skill that helps determine the functional level of a person. Assessment of the STS movement has been done using quantitative and semiquantitative techniques. The purposes of this study were to identify the determinants of the STS movement and to describe their influence on the performance of the STS movement. Methods. A search was made using MEDLINE (1980–2001) and the Science Citation Index Expanded of the Institute for Scientific Information (1988–2001) using the key words “chair,” “mobility,” “rising,” “sit-to-stand,” and “standing.” Relevant references such as textbooks, presentations, and reports also were included. Of the 160 identified studies, only those in which the determinants of STS movement performance were examined using an experimental setup (n=39) were included in this review. Results. The literature indicates that chair seat height, use of armrests, and foot position have a major influence on the ability to do an STS movement. Using a higher chair seat resulted in lower moments at knee level (up to 60%) and hip level (up to 50%); lowering the chair seat increased the need for momentum generation or repositioning of the feet to lower the needed moments. Using the armrests lowered the moments needed at the hip by 50%, probably without influencing the range of motion of the joints. Repositioning of feet influenced the strategy of the STS movement, enabling lower maximum mean extension moments at the hip (148.8 N·m versus 32.7 N·m when the foot position changed from anterior to posterior). Discussion and Conclusion. The ability to do an STS movement, according to the research reviewed, is strongly influenced by the height of the chair seat, use of armrests, and foot position. More study of the interaction among the different determinants is needed. Failing to account for these variables may lead to erroneous measurements of changes in STS performance.
Collapse
Affiliation(s)
- Wim GM Janssen
- WGM Janssen, MD, is Rehabilitation Specialist, Department of Rehabilitation, University Hospital Rotterdam, Dr Molewaterplein 40, 3015 GD Rotterdam, the Netherlands
| | - Hans BJ Bussmann
- HBJ Bussmann, PT, PhD, is Assistant Professor, Department of Rehabilitation, Erasmus University Rotterdam, Rotterdam, the Netherlands
| | - Henk J Stam
- HJ Stam, MD, PhD, is Rehabilitation Specialist, Professor and Head of the Department of Rehabilitation Medicine, University Hospital Rotterdam and Erasmus University Rotterdam
| |
Collapse
|
26
|
Abstract
The problem of assessing the physical functional limitation of a given individual and establishing the relationship between impairment/s and disability using a biomechanical approach is addressed. This endeavour was pursued with reference to the locomotor system and in order to address the following specific clinical issues: prognosis, eligibility for health services, measure of the outcome of a therapy, and therapeutic programming. A thorough biomechanical analysis of selected motor tasks would be effective but awkward to apply for subject-specific evaluation in clinical practice by reason of the complexity of both instrumentation and experimental protocols. In addition, as illustrated in the paper, the adequacy of the accuracy with which this type of analysis provides relevant information may be argued. Therefore, different methods were devised in the attempt to join objectivity with field applicability. These entailed the measurement of a minimum number of biomechanical variables during the execution of the selected motor task and these quantities were acquired using a low cost experimental apparatus least perceivable to the test subject, that is a dynamometric plate. However, since data thus obtained do not necessarily lend themselves to straightforward interpretation in terms of function assessment, models of the musculo-skeletal system that embodied the invariant aspects of both the modelled system and the specific motor task were devised. Using such "minimum measured-input models", physiology-related, and thus easier to interpret, information was obtained. Two different sets of mathematical models are presented: one deals with the lowest level of detail and normally aims at assessing a global physical performance score, the other discloses joint function and segmental mechanics and therefore contributes to establishing a relationship between impairment and disability. The validation of these models, carried out in the laboratory, has shown that they possess a potential for application in clinical practice.
Collapse
Affiliation(s)
- Aurelio Cappozzo
- Istituto Universitario di Scienze Motorie, Piazza Lauro de Bosis, 15, 00194 Roma, Italy.
| |
Collapse
|
27
|
Bonato P, Boissy P, Della Croce U, Roy SH. Changes in the surface EMG signal and the biomechanics of motion during a repetitive lifting task. IEEE Trans Neural Syst Rehabil Eng 2002; 10:38-47. [PMID: 12173738 DOI: 10.1109/tnsre.2002.1021585] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The analysis of surface electromyographic (EMG) data recorded from the muscles of the back during isometric constant-force contractions has been a useful tool for assessing muscle deficits in patients with lower back pain (LBP). Until recently, extending the technique to dynamic tasks, such as lifting, has not been possible due to the nonstationarity of the EMG signals. Recent developments in time-frequency analysis procedures to compute the instantaneous median frequency (IMDF) were utilized in this study to overcome these limitations. Healthy control subjects with no history of LBP (n = 9; mean age 26.3 +/- 6.7) were instrumented for acquisition of surface EMG data from six electrodes on the thoraco-lumbar region and whole-body kinematic data from a stereo-photogrammetric system. Data were recorded during a standardized repetitive lifting task (load = 15% body mass; 12 lifts/min; 5-min duration). The task resulted in significant decreases in IMDF for six of the nine subjects, with a symmetrical pattern of fatigue among contralateral muscles and greater decrements in the lower lumbar region. For those subjects with a significant decrease in IMDF, a lower limb and/or upper limb biomechanical adaptation to fatigue was observed during the task. Increases in the peak box acceleration were documented. In two subjects, the acceleration doubled its value from the beginning to the end of the exercise, which lead to a significant increase in the torque at L4/L5. This observation suggests an association between muscle fatigue at the lumbar region and the way the subject manipulates the box during the exercise. Fatigue-related biomechanical adaptations are discussed as a possible supplement to functional capacity assessments among patients with LBP.
Collapse
Affiliation(s)
- Paolo Bonato
- NeuroMuscular Research Center, Boston University, MA 02215, USA.
| | | | | | | |
Collapse
|
28
|
Papa E, Cappozzo A. Sit-to-stand motor strategies investigated in able-bodied young and elderly subjects. J Biomech 2000; 33:1113-22. [PMID: 10854884 DOI: 10.1016/s0021-9290(00)00046-4] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
For the execution of a certain motor task, a motor strategy is chosen by each individual among those that are consistent with the structural and functional constraints of his/her locomotor system, and that tends to maximise the effectiveness of the motor act. The identification of this strategy allows for the assessment of the individual's functional status. This study aimed at identifying the motor strategies adopted for the execution of the sit-to-stand motor task, at different speeds and initial postures, in a sample of 35 community-dwelling elders and in a sample of 16 young able-bodied individuals. This was done using a method, least perceivable to the test subject and "economical" for the experimenter, which entailed the recording of external forces only. A musculo-skeletal system model, based on a telescopic inverted-pendulum (TIP) moved by a linear and two rotational muscle-equivalent actuators, was then used. Parameters describing the kinematics and dynamics of these actuators were extracted and submitted to statistical analysis. Different motor strategies were identified in the two age groups, as well as associated with both a different initial posture (ankle dorsiflexion angle) and speed of execution of the motor task. In particular, the elder group, as compared with the young group, prior to seat-off tended to flex the trunk more, thus bringing the CM closer to the base of support, and at a higher velocity, thus gaining a higher momentum. After seat-off, elders rotated the body forward and, only after having brought their CM over the base of support, effectively started elevation. Both global muscular effort and coordination effort associated with the achievement of balance and raising were lower. However, maximal speed was also lower. The above results indicated that the elders could count on a lower functional reserve than the young individuals and, from the methodological viewpoint, that the TIP approach is a good candidate for subject-specific functional evaluation in a clinical context.
Collapse
Affiliation(s)
- E Papa
- Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Italy
| | | |
Collapse
|