1
|
Towles JD. The Sensitivity of the Endpoint Forces of Thumb Extrinsic and Intrinsic Muscles to Changes in Joint Angles, Muscle Moment Arms and Bone Lengths in the Flexed Thumb. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-7. [PMID: 38083462 DOI: 10.1109/embc40787.2023.10340552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
A previous study showed in situ measurements of thumb-tip forces produced by muscles vary substantially among cadaveric specimens. Potential sources of variability include inter-specimen anatomic differences and postural deviations from the nominal posture in which the specimens were tested. This study aimed to theoretically determine the variation in thumb-tip force caused by inter-specimen differences in thumb anatomy and posture. We developed a two-dimensional mathematical model of force production at the thumb tip based on published estimates of muscle moment arms, bone length, and joint angle measurements from nine cadaveric specimens. The model was placed in a flexed posture. Using the model, we calculated variations in magnitude and direction of each muscle's thumb-tip force induced by a ±1 standard deviation (or equivalent) variation in each bone length, the moment arm of the muscle (i.e., anatomic factors), and each joint angle (i.e., postural factor). For most muscles, inter-specimen differences in the metacarpophalangeal (MP) joint angle produced at least a 75% larger variation in thumb-tip force magnitude than that produced by other factors. For all muscles, differences in the interphalangeal joint angle among specimens produced the largest variation in thumb-tip force direction. For some muscles, inter-specimen differences in bone lengths, moment arms, and MP joint angles also produced large variations in thumb-tip force direction. This study suggests deviation from the nominal flexed thumb posture and large measurement variability in muscle moment arms are primary and secondary sources, respectively, of variability in thumb-tip forces produced by the majority of thumb muscles. Further, this study suggests a more careful approach to standardizing the thumb posture would likely improve current measurements of thumb-tip forces.Clinical Relevance- This work describes the influence of anatomic and postural factors on thumb-tip forces that thumb muscles produce. The results of this work have implications for musculoskeletal modeling and surgical reconstruction of grasp.
Collapse
|
2
|
Towles JD. Measurement of the Three-Dimensional Muscle Endpoint Forces in the Extended Thumb and Its Application to Determining Muscle Combinations that Enable Lateral Pinch Force Production Throughout the Plane of Flexion-Extension. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-5. [PMID: 38083628 DOI: 10.1109/embc40787.2023.10340817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Functional outcomes of tendon transfer surgeries, designed to restore lateral pinch grasp to persons following cervical spinal cord injury, have been mixed. That is, pinch force magnitudes have varied by 10-fold and have been reported to be as low as low as tenths of a pound. We believe a novel tendon transfer approach in which the donor muscle actuates a small group of paralyzed thumb muscles, instead of just the flexor pollicis longus (FPL) muscle (the current approach), will enable endpoint forces that are better directed and therefore a consistently stronger pinch force following surgery. We further believe that such surgeries can be better designed to account for grasp force production throughout the entire plane of flexion-extension if muscle endpoint forces in the extended thumb are known. Consequently, we measured muscle endpoint forces in the extended thumb in 6 cadaveric specimens after a force of 10 N was applied to each muscle. Further, we simulated a tendon transfer surgery in which the donor muscle applied equal force to each muscle in 246 small groups of muscles, calculated the direction of the resulting endpoint force throughout the flexion-extension plane, and determined if those groups of muscles produced a better directed force than FPL's. While we found that 3 individual muscles and 52 muscle groups could produce desirably directed endpoint forces in parts of the flexion-extension plane, no muscle or muscle group could produce well-directed endpoint forces throughout the flexion-extension plane. We concluded that a group of muscles could likely be found if the donor muscle provided different levels of force to each of the muscles in a muscle group. This would be possible through intentional geometric manipulation of the donor-to-recipient muscle attachment to allow for unequal splitting of donor muscle force.Clinical Relevance-This work aims to determine whether the same combination of thumb muscles can produce well-directed endpoint forces throughout the flexion-extension plane. If so, then this work informs surgeons which muscle groups could be involved in a tendon transfer to restore lateral pinch grasp ability throughout the plane of flexion-extension in person with cervical spinal cord injury.
Collapse
|
3
|
McFarland DC, Wohlman SJ, Murray WM. Corrigendum to "Bridging the gap between cadaveric and in vivo experiments: A biomechanical model evaluating thumb-tip endpoint forces" [J. Biomech. 46(5) (2013) 1014-1020]. J Biomech 2021; 139:110858. [PMID: 34809997 DOI: 10.1016/j.jbiomech.2021.110858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Daniel C McFarland
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA; Shirley Ryan AbilityLab, Chicago, IL, USA; Edward Hines, Jr. VA Hospital, Hines, IL, USA
| | - Sarah J Wohlman
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA; Shirley Ryan AbilityLab, Chicago, IL, USA
| | - Wendy M Murray
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA; Department of Physical Medicine & Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, IL, USA; Shirley Ryan AbilityLab, Chicago, IL, USA; Edward Hines, Jr. VA Hospital, Hines, IL, USA.
| |
Collapse
|
4
|
Yozbatiran N, Russell M, Korupolu R, Grossman R, Toups E, Francisco G. Reliability of peg restrained intrinsic muscle evaluator for measurement of intrinsic hand muscle strength in adults with tetraplegia. THE JOURNAL OF THE INTERNATIONAL SOCIETY OF PHYSICAL AND REHABILITATION MEDICINE 2021. [DOI: 10.4103/jisprm.jisprm_27_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
5
|
Cohn BA, Szedlák M, Gärtner B, Valero-Cuevas FJ. Feasibility Theory Reconciles and Informs Alternative Approaches to Neuromuscular Control. Front Comput Neurosci 2018; 12:62. [PMID: 30254579 PMCID: PMC6141757 DOI: 10.3389/fncom.2018.00062] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/11/2018] [Indexed: 01/19/2023] Open
Abstract
We present Feasibility Theory, a conceptual and computational framework to unify today's theories of neuromuscular control. We begin by describing how the musculoskeletal anatomy of the limb, the need to control individual tendons, and the physics of a motor task uniquely specify the family of all valid muscle activations that accomplish it (its ‘feasible activation space’). For our example of producing static force with a finger driven by seven muscles, computational geometry characterizes—in a complete way—the structure of feasible activation spaces as 3-dimensional polytopes embedded in 7-D. The feasible activation space for a given task is the landscape where all neuromuscular learning, control, and performance must occur. This approach unifies current theories of neuromuscular control because the structure of feasible activation spaces can be separately approximated as either low-dimensional basis functions (synergies), high-dimensional joint probability distributions (Bayesian priors), or fitness landscapes (to optimize cost functions).
Collapse
Affiliation(s)
- Brian A Cohn
- Department of Computer Science, University of Southern California, Los Angeles, CA, United States
| | - May Szedlák
- Department of Theoretical Computer Science, ETH Zurich, Zurich, Switzerland
| | - Bernd Gärtner
- Department of Theoretical Computer Science, ETH Zurich, Zurich, Switzerland
| | - Francisco J Valero-Cuevas
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States.,Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, United States
| |
Collapse
|
6
|
Barry AJ, Murray WM, Kamper DG. Development of a dynamic index finger and thumb model to study impairment. J Biomech 2018; 77:206-210. [PMID: 30017546 DOI: 10.1016/j.jbiomech.2018.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 06/08/2018] [Accepted: 06/19/2018] [Indexed: 10/28/2022]
Abstract
Modeling of the human hand provides insight for explaining deficits and planning treatment following injury. Creation of a dynamic model, however, is complicated by the actions of multi-articular tendons and their complex interactions with other soft tissues in the hand. This study explores the creation of a musculoskeletal model, including the thumb and index finger, to explore the effects of muscle activation deficits. The OpenSim model utilizes physiological axes of rotation at all joints, passive joint torques, and appropriate moment arms. The model was validated through comparison with kinematic and kinetic experimental data. Simulated fingertip forces resulting from modeled musculotendon loading largely fell within one standard deviation of experimental ranges for most index finger and thumb muscles, although agreement in the sagittal plane was generally better than for the coronal plane. Input of experimentally obtained electromyography data produced the expected simulated finger and thumb motion. Use of the model to predict the effects of activation deficits on pinch force production revealed that the intrinsic muscles, especially first dorsal interosseous (FDI) and adductor pollicis (ADP), had a substantial impact on the resulting fingertip force. Reducing FDI activation, such as might occur following stroke, altered fingertip force direction by up to 83° for production of a dorsal fingertip force; reducing ADP activation reduced force production in the thumb by up to 62%. This validated model can provide a means for evaluating clinical interventions.
Collapse
Affiliation(s)
| | - Wendy M Murray
- Shirley Ryan AbilityLab, Chicago, IL, United States; Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States; Department of Physical Medicine & Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, IL, United States; Department of Physical Therapy and Human Movement Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, United States; Edward Hines, Jr. VA Hospital, Hines, IL, United States
| | - Derek G Kamper
- Department of Physical Medicine & Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, IL, United States; UNC/NC State Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC, United States; Closed-Loop Engineering for Advanced Rehabilitation Research Core, North Carolina State University, Raleigh, NC, United States
| |
Collapse
|
7
|
Qiu D, Lee SW, Amine M, Kamper DG. Intersegmental kinetics significantly impact mapping from finger musculotendon forces to fingertip forces. J Biomech 2017; 65:82-88. [PMID: 29102266 DOI: 10.1016/j.jbiomech.2017.10.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 08/13/2017] [Accepted: 10/01/2017] [Indexed: 11/30/2022]
Abstract
Predicting the fingertip force vector resulting from excitation of a given muscle remains a challenging but essential task in finger biomechanical modeling. While the conversion of musculotendon force to fingertip force can significantly be affected by finger posture, current techniques utilizing geometric moment arms may not capture such complex postural effects. Here, we attempted to elucidate the postural effects on the mapping between musculotendon force and fingertip force through in vitro experiments. Computer-controlled tendon loading was implemented on the 7 index finger musculotendons of 5 fresh-frozen cadaveric hands across different postures. The resulting fingertip forces/moments were used to compute the effective static moment arm (ESMA), relating tendon force to joint torque, at each joint. The ESMAs were subsequently modeled in three different manners: independent of joint angle; dependent only upon the corresponding joint angle; or dependent upon all joint angles. We found that, for the reconstruction of the fingertip force vector, the multi-joint ESMA model yielded the best outcome, both in terms of direction and magnitude of the vector (mean reconstruction error <4° in direction and <2% in the magnitude), which indicates that intersegmental force transmission through a joint is affected by the posture of neighboring joints. Interestingly, the ESMA model that considers geometric changes of individual joints, the standard model used in biomechanical stimulations, often yielded worse reconstruction results than the simple constant-value ESMA model. Our results emphasize the importance of accurate description of the multi-joint dependency of the conversion of tendon force to joint moment for proper prediction of fingertip force direction.
Collapse
Affiliation(s)
- Dan Qiu
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States.
| | - Sang Wook Lee
- Department of Biomedical Engineering, Catholic University of America, Washington, DC, United States; Center for Applied Biomechanics and Rehabilitation Research, MedStar National Rehabilitation Hospital, Washington, DC, United States
| | - Mukarram Amine
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States
| | - Derek G Kamper
- UNC/NC State Joint Department of Biomedical Engineering and Rehabilitation Engineering Core, North Carolina State University, Raleigh, NC, United States; UNC/NC State Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, United States
| |
Collapse
|
8
|
Niehues TD, Deshpande AD. Variable Thumb Moment Arm Modeling and Thumb-Tip Force Production of a Human-Like Robotic Hand. J Biomech Eng 2017; 139:2646919. [PMID: 28753689 DOI: 10.1115/1.4037402] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Indexed: 11/08/2022]
Abstract
The anatomically correct testbed (ACT) hand mechanically simulates the musculoskeletal structure of the fingers and thumb of the human hand. In this work, we analyze the muscle moment arms (MAs) and thumb-tip force vectors in the ACT thumb in order to compare the ACT thumb's mechanical structure to the human thumb. Motion data are used to determine joint angle-dependent MA models, and thumb-tip three-dimensional (3D) force vectors are experimentally analyzed when forces are applied to individual muscles. Results are presented for both a nominal ACT thumb model designed to match human MAs and an adjusted model that more closely replicates human-like thumb-tip forces. The results confirm that the ACT thumb is capable of faithfully representing human musculoskeletal structure and muscle functionality. Using the ACT hand as a physical simulation platform allows us to gain a better understanding of the underlying biomechanical and neuromuscular properties of the human hand to ultimately inform the design and control of robotic and prosthetic hands.
Collapse
Affiliation(s)
- Taylor D Niehues
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712 e-mail:
| | - Ashish D Deshpande
- Mem. ASME Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712 e-mail:
| |
Collapse
|
9
|
Towles JD, Valero-Cuevas FJ, Hentz VR. Capacity of small groups of muscles to accomplish precision grasping tasks. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2013:6583-6. [PMID: 24111251 DOI: 10.1109/embc.2013.6611064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
An understanding of the capacity or ability of various muscle groups to generate endpoint forces that enable grasping tasks could provide a stronger biomechanical basis for the design of reconstructive surgery or rehabilitation for the treatment of the paralyzed or paretic hand. We quantified two-dimensional endpoint force distributions for every combination of the muscles of the index finger, in cadaveric specimens, to understand the capability of muscle groups to produce endpoint forces that accomplish three common types of grasps-tripod, tip and lateral pinch-characterized by a representative level of Coulomb friction. We found that muscle groups of 4 or fewer muscles were capable of generating endpoint forces that enabled performance of each of the grasping tasks examined. We also found that flexor muscles were crucial to accomplish tripod pinch; intrinsic muscles, tip pinch; and the dorsal interosseus muscle, lateral pinch. The results of this study provide a basis for decision making in the design of reconstructive surgeries and rehabilitation approaches that attempt to restore the ability to perform grasping tasks with small groups of muscles.
Collapse
|
10
|
Kong S, Lee KS, Kim J, Jang SH. The effect of two different hand exercises on grip strength, forearm circumference, and vascular maturation in patients who underwent arteriovenous fistula surgery. Ann Rehabil Med 2014; 38:648-57. [PMID: 25379494 PMCID: PMC4221393 DOI: 10.5535/arm.2014.38.5.648] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/03/2014] [Indexed: 11/16/2022] Open
Abstract
Objective To compare the effect of two different hand exercises on hand strength and vascular maturation in patients who underwent arteriovenous fistula surgery. Methods We recruited 18 patients who had chronic kidney disease and had undergone arteriovenous fistula surgery for hemodialysis. After the surgery, 10 subjects performed hand-squeezing exercise with GD Grip, and other 8 subjects used Soft Ball. The subjects continued the exercises for 4 weeks. The hand grip strength, pinch strength (tip, palmar and lateral pinch), and forearm circumference of the subjects were assessed before and after the hand-squeezing exercise. The cephalic vein size, blood flow velocity and volume were also measured by ultrasonography in the operated limb. Results All of the 3 types of pinch strengths, grip strength, and forearm circumference were significantly increased in the group using GD Grip. Cephalic vein size and blood flow volume were also significantly increased. However, blood flow velocity showed no difference after the exercise. The group using Soft Ball showed a significant increase in the tip and lateral pinch strength and forearm circumference. The cephalic vein size and blood flow volume were also significantly increased. On comparing the effect of the two different hand exercises, hand-squeezing exercise with GD Grip had a significantly better effect on the tip and palmar pinch strength than hand-squeezing exercise with Soft Ball. The effect on cephalic vein size was not significantly different between the two groups. Conclusion The results showed that hand squeezing exercise with GD Grip was more effective in increasing the tip and palmar pinch strength compared to hand squeezing exercise with soft ball.
Collapse
Affiliation(s)
- Sangwon Kong
- Department of Rehabilitation Medicine, Hanyang University College of Medicine, Seoul, Korea
| | - Kyung Soo Lee
- Department of Rehabilitation Medicine, Hanyang University College of Medicine, Seoul, Korea
| | - Junho Kim
- Department of Rehabilitation Medicine, Hanyang University College of Medicine, Seoul, Korea
| | - Seong Ho Jang
- Department of Rehabilitation Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea
| |
Collapse
|
11
|
Kamper DG, Fischer HC, Conrad MO, Towles JD, Rymer WZ, Triandafilou KM. Finger-thumb coupling contributes to exaggerated thumb flexion in stroke survivors. J Neurophysiol 2014; 111:2665-74. [PMID: 24671534 DOI: 10.1152/jn.00413.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The purpose of this study was to investigate altered finger-thumb coupling in individuals with chronic hemiparesis poststroke. First, an external device stretched finger flexor muscles by passively rotating the metacarpophalangeal (MCP) joints. Subjects then performed isometric finger or thumb force generation. Forces/torques and electromyographic signals were recorded for both the thumb and finger muscles. Stroke survivors with moderate (n = 9) and severe (n = 9) chronic hand impairment participated, along with neurologically intact individuals (n = 9). Stroke survivors exhibited strong interactions between finger and thumb flexors. The stretch reflex evoked by stretch of the finger flexors of stroke survivors led to heteronymous reflex activity in the thumb, while attempts to produce isolated voluntary finger MCP flexion torque/thumb flexion force led to increased and undesired thumb force/finger MCP torque production poststroke with a striking asymmetry between voluntary flexion and extension. Coherence between the long finger and thumb flexors estimated using intermuscular electromyographic correlations, however, was small. Coactivation of thumb and finger flexor muscles was common in stroke survivors, whether activation was evoked by passive stretch or voluntary activation. The coupling appears to arise from subcortical or spinal sources. Flexor coupling between the thumb and fingers seems to contribute to undesired thumb flexor activity after stroke and may impact rehabilitation outcomes.
Collapse
Affiliation(s)
- Derek G Kamper
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois; Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, Illinois; and
| | - Heidi C Fischer
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, Illinois; and
| | - Megan O Conrad
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, Illinois; and
| | - Joseph D Towles
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, Illinois; and Rehabilitation R&D Service, Edward Hines Jr. Veterans Affairs Hospital, Hines, Illinois
| | - William Z Rymer
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, Illinois; and Rehabilitation R&D Service, Edward Hines Jr. Veterans Affairs Hospital, Hines, Illinois
| | - Kristen M Triandafilou
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, Illinois; and
| |
Collapse
|
12
|
Wohlman SJ, Murray WM. Bridging the gap between cadaveric and in vivo experiments: a biomechanical model evaluating thumb-tip endpoint forces. J Biomech 2013; 46:1014-20. [PMID: 23332233 DOI: 10.1016/j.jbiomech.2012.10.044] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 10/25/2012] [Accepted: 10/26/2012] [Indexed: 10/27/2022]
Abstract
The thumb is required for a majority of tasks of daily living. Biomechanical modeling is a valuable tool, with the potential to help us bridge the gap between our understanding of the mechanical actions of individual thumb muscles, derived from anatomical cadaveric experiments, and our understanding of how force is produced by the coordination of all of the thumb muscles, derived from studies involving human subjects. However, current biomechanical models do not replicate muscle force production at the thumb-tip. We hypothesized that accurate representations of the axes of rotation of the thumb joints were necessary to simulate the magnitude of endpoint forces produced by human subjects. We augmented a musculoskeletal model with axes of rotation derived from experimental measurements (Holzbaur et al., 2005) by defining muscle-tendon paths and maximum isometric force-generating capacity for the five intrinsic muscles. We then evaluated if this augmented model replicated a broad range of experimental data from the literature and identified which parameters most influenced model performance. The simulated endpoint forces generated by the combined action of all thumb muscles in our model yielded comparable forces in magnitude to those produced by nonimpaired subjects. A series of 8 sets of Monte Carlo simulations demonstrated that the difference in the axes of rotation of the thumb joints between studies best explains the improved performance of our model relative to previous work. In addition, we demonstrate that the endpoint forces produced by individual muscles cannot be replicated with existing experimental data describing muscle moment arms.
Collapse
Affiliation(s)
- Sarah J Wohlman
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | | |
Collapse
|
13
|
Cash DJW, Jones JWM. The role of tenodesis in surgery of the upper limb. THE JOURNAL OF BONE AND JOINT SURGERY. BRITISH VOLUME 2011; 93:285-292. [PMID: 21357947 DOI: 10.1302/0301-620x.93b3.25797] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This paper describes the presence of tenodesis effects in normal physiology and explores the uses of operative tenodesis in surgery of the upper limb.
Collapse
Affiliation(s)
- D J W Cash
- Peterborough and Stamford Hospitals NHS Foundation Trust, Peterborough, United Kingdom.
| | | |
Collapse
|
14
|
Goehler CM, Murray WM. The sensitivity of endpoint forces produced by the extrinsic muscles of the thumb to posture. J Biomech 2010; 43:1553-9. [PMID: 20303085 DOI: 10.1016/j.jbiomech.2010.01.032] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Revised: 12/28/2009] [Accepted: 01/06/2010] [Indexed: 11/25/2022]
Abstract
This study utilizes a biomechanical model of the thumb to estimate the force produced at the thumb-tip by each of the four extrinsic muscles. We used the principle of virtual work to relate joint torques produced by a given muscle force to the resulting endpoint force and compared the results to two separate cadaveric studies. When we calculated thumb-tip forces using the muscle forces and thumb postures described in the experimental studies, we observed large errors. When relatively small deviations from experimentally reported thumb joint angles were allowed, errors in force direction decreased substantially. For example, when thumb posture was constrained to fall within +/-15 degrees of reported joint angles, simulated force directions fell within experimental variability in the proximal-palmar plane for all four muscles. Increasing the solution space from +/-1 degrees to an unbounded space produced a sigmoidal decrease in error in force direction. Changes in thumb posture remained consistent with a lateral pinch posture, and were generally consistent with each muscle's function. Altering thumb posture alters both the components of the Jacobian and muscle moment arms in a nonlinear fashion, yielding a nonlinear change in thumb-tip force relative to muscle force. These results explain experimental data that suggest endpoint force is a nonlinear function of muscle force for the thumb, support the continued use of methods that implement linear transformations between muscle force and thumb-tip force for a specific posture, and suggest the feasibility of accurate prediction of lateral pinch force in situations where joint angles can be measured accurately.
Collapse
Affiliation(s)
- Craig M Goehler
- Sensory Motor Performance Program, Rehabilitation Institute of Chicago, 345 E. Superior Street, Room 1408B, Chicago, IL, USA
| | | |
Collapse
|