1
|
Calver R, Cudlip A, Dickerson CR, Mondal P, Butcher S, Kim SY. A comparison of isometric and isokinetic normalization methods for electromyographic data from sub-regions of supraspinatus and infraspinatus during dynamic tasks. Int Biomech 2023; 10:1-9. [PMID: 37183477 DOI: 10.1080/23335432.2023.2210634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023] Open
Abstract
This study explored effects of using isometric versus isokinetic maximal voluntary contractions (MVCs) to normalize EMG data from supraspinatus and infraspinatus subregions during isokinetic tasks. Participants performed submaximal isokinetic external rotation (ER) and scaption tasks at two speeds. Three isometric MVCs were used: seated ER; side-lying scaption; side-lying abduction. Isokinetic MVCs were performed in the same position and speeds as the experimental tasks. Data were normalized using peak EMG from reference tasks: MVC which produced the greatest amplitude overall (MEA), isometric MVC with greatest amplitude (isometric best), isokinetic MVC with greatest amplitude (isokinetic best), and the greatest amplitude from the isokinetic MVC that matched the experimental task (isokinetic matched). Mean %MVC from each experimental task/ sub-region were compared by normalization method. The isokinetic matched method versus the MEA method was significantly different in all comparisons with isokinetic matched resulting in relative normalized task values up to 162% greater. The isometric best method resulted in significantly greater %MVC 37% of the time compared to the MEA method, whereas there were no differences when using isokinetic best compared to MEA. Isokinetic MVCs are less likely to overestimate %MVC than isometric and their use should be considered when normalizing data from dynamic tasks.
Collapse
Affiliation(s)
- Ronelle Calver
- Department of Medicine, Physical Medicine and Rehabilitation, McMaster University, Hamilton, Canada
- College of Medicine, Department of Physical Medicine and Rehabilitation, University of Saskatchewan, Saskatoon, Canada
- College of Medicine, School of Rehabilitation Science, University of Saskatchewan, Saskatoon, Canada
| | - Alan Cudlip
- College of Medicine, Department of Physical Medicine and Rehabilitation, University of Saskatchewan, Saskatoon, Canada
| | - Clark R Dickerson
- Department of Kinesiology, Neuromechanics and Ergonomics Lab, Brock University, Ontario Canada
| | - Prosanta Mondal
- Faculty of Applied Health Sciences, Department of Kinesiology, Digital Industrial Ergonomics and Shoulder Evaluation Laboratory (DIESEL), University of Waterloo, Ontario, Canada
| | - Scotty Butcher
- College of Medicine, Department of Community Health and Epidemiology, University of Saskatchewan, Saskatoon, Canada
| | - Soo Y Kim
- College of Medicine, Department of Community Health and Epidemiology, University of Saskatchewan, Saskatoon, Canada
| |
Collapse
|
2
|
Dickerson CR, McDonald AC, Chopp-Hurley JN. Between Two Rocks and in a Hard Place: Reflecting on the Biomechanical Basis of Shoulder Occupational Musculoskeletal Disorders. HUMAN FACTORS 2023; 65:879-890. [PMID: 31961724 DOI: 10.1177/0018720819896191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
OBJECTIVE The aim was to review the biomechanical origins of occupational shoulder damage, while considering the complexity of shoulder mechanics and musculoskeletal consequences of diverse task demands. BACKGROUND Accessible measures of physical exposures are the primary focus of occupational shoulder assessments and analyses. This approach has led to guidelines and intervention strategies that are often inadequate for mitigating shoulder disorders amongst the complexity of modern workplace demands. Integration of complex shoulder mechanics into occupational assessments, analyses, and interventions is critical for reducing occupational shoulder injury risk. METHOD This narrative review describes shoulder biomechanics in the context of common injury mechanisms and consequent injuries, with a particular focus on subacromial impingement syndrome. Several modulators of shoulder injury risk are reviewed, including fatigue, overhead work, office ergonomics considerations, and pushing and pulling task configurations. RESULTS Relationships between work requirements, muscular demands, fatigue, and biomechanical tissue loads exist. This review highlights that consideration of specific workplace factors should be integrated with our knowledge of the intricate arrangement and interpersonal variability of the shoulder complex to proactively evaluate occupational shoulder demands and exposures. CONCLUSION A standard method for evaluating shoulder muscle exposures during workplace tasks does not exist. An integrated approach is critical for improved work design and prevention of shoulder tissue damage and accompanying disability. APPLICATION This review is particularly relevant for researchers and practitioners, providing guidance for work design and evaluation for shoulder injury prevention by understanding the importance of the unique and complex mechanics of the shoulder.
Collapse
|
3
|
Muscle fatigue response of rotator cuff muscles in different postures. Arch Orthop Trauma Surg 2022; 143:3191-3199. [PMID: 36305967 DOI: 10.1007/s00402-022-04650-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/08/2022] [Indexed: 02/09/2023]
Abstract
INTRODUCTION Muscle fatigue is a leading cause of rotator cuff (RC) pathologies. Scapular orientation affected by changes in the thoracic spine account for differences in body postures leading to altered RC muscle activation. This posture-related alteration in RC muscle activation and its fatigue response needs to be analyzed. MATERIALS AND METHODS This study included 50 healthy shoulders with no coexisting spine pathologies. Raw data were recorded using electromyography sensors for RC muscles during two isometric maneuvers of abduction and external rotation, performed at 30% maximum voluntary contraction at 30°, 45°, and 90° arm elevation in sitting and standing. The raw data were analyzed in DataLITE® software, and the mean power frequency (MPF) was extracted to analyze the fatigue response of RC muscles. The Wilcoxon signed-rank test and Kruskal-Wallis test with Bonferroni corrections analyzed fatigue differences between postures and various activities. P < 0.05 was considered significant for the results. RESULTS Supraspinatus muscle demonstrated significant fatigue at 90° of arm elevation in standing as compared to sitting (MPF -5.40: -5.41; P = 0.03) posture. Between the three elevation angles, all the RC muscles showed increased fatigue at 90° (MPF range -5.22 to -6.64). When compared between abduction and external rotation, only infraspinatus showed fatigue in external rotation (MPF range -5.42 to -6.08). Among all the three RC muscles, infraspinatus showed the maximum fatigue of MPF -6.64 when compared to supraspinatus -5.22 and teres minor -5.36. CONCLUSION The findings indicate that alterations in the body postures and different elevation angles affect the RC muscles' fatigue response.
Collapse
|
4
|
Lulic-Kuryllo T, Negro F, Jiang N, Dickerson CR. Differential regional pectoralis major activation indicates functional diversity in healthy females. J Biomech 2022; 133:110966. [DOI: 10.1016/j.jbiomech.2022.110966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 01/13/2022] [Accepted: 01/17/2022] [Indexed: 11/26/2022]
|
5
|
Zaluski AJ, Campbell J, Hlasny M, Nedjelski M, Thompson T, Vanneste A, Kim SY. Activation of neuromuscular sub-regions of supraspinatus and infraspinatus during common rehabilitative exercises. J Electromyogr Kinesiol 2021; 61:102604. [PMID: 34587575 DOI: 10.1016/j.jelekin.2021.102604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 09/11/2021] [Accepted: 09/15/2021] [Indexed: 11/30/2022] Open
Abstract
'Regional activation' has been identified within the supraspinatus and infraspinatus. Previous EMG studies have provided insight on the different functions of the sub-regions within the supraspinatus and infraspinatus, however, to date timing of peak EMG activation has not been investigated. To assess how theses sub-regions function during commonly prescribed rehabilitation exercises, electrodes were inserted into the supraspinatus - anterior and posterior- and infraspinatus - superior and middle - of 22 healthy participants. For each sub-region, normalized EMG data - amplitude and timing - was collected from nine rehabilitation exercises - three with an elastic band and six an exercise ball. Supraspinatus posterior and infraspinatus superior had similar activation levels between elastic band exercises, but the timing of peak activation was exercise specific. In all elastic band exercises, supraspinatus posterior activated prior to supraspinatus anterior. All ball exercises elicited low-amplitude muscle activation; dynamic ball exercises had higher peak muscle activation than their static counterparts.
Collapse
Affiliation(s)
- Alexandra J Zaluski
- School of Rehabilitation Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Jeremy Campbell
- School of Rehabilitation Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Magda Hlasny
- School of Rehabilitation Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Mason Nedjelski
- School of Rehabilitation Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Tanner Thompson
- School of Rehabilitation Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Alex Vanneste
- School of Rehabilitation Sciences, University of Saskatchewan, Saskatoon, Canada
| | - Soo Y Kim
- School of Rehabilitation Sciences, University of Saskatchewan, Saskatoon, Canada.
| |
Collapse
|
6
|
Quantifying supraspinatus tendon responses to exposures emulative of human physiological levels in an animal model. J Biomech 2021; 122:110476. [PMID: 33933860 DOI: 10.1016/j.jbiomech.2021.110476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 02/21/2021] [Accepted: 04/19/2021] [Indexed: 11/21/2022]
Abstract
Rotator cuff pathology typically originates in the supraspinatus tendon, but uncertainty exists on how combinations of glenohumeral elevation angle and load intensity influence responses of the intact, functional supraspinatus unit. This study exposed the supraspinatus tendon to mechanical loading scenarios emulative of derived muscle force and postural conditions measured in vivo to document its responses. Right shoulders from 48 Sprague-Dawley rats were placed into one of eight testing groups combining glenohumeral elevation angles (0/30/60/75°) and a high or low load intensity for 1500 cycles at 0.25 Hz using a custom mounting apparatus attached to a tensile testing system. Load intensities were derived from in vivo human partitional muscular activation levels collected previously and scaled to the animal model. Mechanical response variables examined included tangent stiffness and hysteresis, in addition to localized surface stretch ratios calculated via virtual tracking points. A significant three-way interaction (p = 0.0009) between elevation angle, load magnitude and cycle number occurred for tangent stiffness, with increasing angles, loads and cycles increasing stiffness by up to 49%. Longitudinal stretch ratios had significant interactions (p = 0.0396) with increasing elevation angles, load intensities and cycle numbers, and differences existed between the articular and bursal sides of the tendon. Complex interactions between angle, load and cycle number suggest higher abduction angles, increased load magnitude and higher loading cycles increase tangent stiffness, stretch ratios and hysteresis within the tendon.
Collapse
|
7
|
Bench RW, Thompson SE, Cudlip AC, Holmes MW. Examining Muscle Activity Differences During Single and Dual Vector Elastic Resistance Exercises. Int J Sports Phys Ther 2021; 16:322-334. [PMID: 33842028 PMCID: PMC8016432 DOI: 10.26603/001c.21309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 10/20/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Elastic resistance exercise is a common part of rehabilitation programs. While these exercises are highly prevalent, little information exists on how adding an additional resistance vector with a different direction from the primary vector alters muscle activity of the upper extremity. PURPOSE The purpose of this study was to examine the effects of dual vector exercises on torso and upper extremity muscle activity in comparison to traditional single vector techniques. STUDY DESIGN Repeated measures design. METHODS Sixteen healthy university-aged males completed four common shoulder exercises against elastic resistance (abduction, flexion, internal rotation, external rotation) while using a single or dual elastic vector at a fixed cadence and standardized elastic elongation. Surface electromyography was collected from 16 muscles of the right upper extremity. Mean, peak and integrated activity were extracted from linear enveloped and normalized data and a 2-way repeated measures ANOVA examined differences between conditions. RESULTS All independent variables differentially influenced activation. Interactions between single/dual vectors and exercise type affected mean activation in 11/16 muscles, while interactions in peak activation existed in 7/16 muscles. Adding a secondary vector increased activation predominantly in flexion or abduction exercises; little changes existed when adding a second vector in internal and external rotation exercises. The dual vector exercise in abduction significantly increased mean activation in lower trapezius by 25.6 ± 8.11 %MVC and peak activation in supraspinatus by 29.4 ± 5.94 %MVC (p<0.01). Interactions between single/dual vectors and exercise type affected integrated electromyography for most muscles; the majority of these muscles had the highest integrated electromyography in the dual vector abduction condition. CONCLUSION Muscle activity often increased with a second resistance vector added; however, the magnitude was exercise-dependent. The majority of these changes existed in the flexion and abduction exercises, with little differences in the internal or external rotation exercises. LEVEL OF EVIDENCE 3b.
Collapse
|
8
|
Lulic-Kuryllo T, Alenabi T, McDonald AC, Kim SY, Dickerson CR. Sub-regional activation of supraspinatus and infraspinatus muscles during activities of daily living is task dependent. J Electromyogr Kinesiol 2020; 54:102450. [PMID: 32711359 DOI: 10.1016/j.jelekin.2020.102450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 07/10/2020] [Accepted: 07/11/2020] [Indexed: 11/18/2022] Open
Abstract
The supraspinatus and infraspinatus muscles each have multiple sub-regions that may activate differentially in activities of daily living. Awareness of these differential demands critically informs rehabilitation of rotator cuff muscle following injury, particularly if centered on recovering and strengthening the rotator cuff to perform daily tasks. This study quantified muscle activation of supraspinatus and infraspinatus sub-regions during the performance of six activities of daily living. Twenty-three participants (mean: 22.6 ± 2.6 years) completed the following tasks: opening a jar, reaching at shoulder height, overhead reaching, pouring water from a pitcher, eating with a spoon, and combing hair. Indwelling electromyography was collected from the anterior and posterior supraspinatus and superior, middle, and inferior infraspinatus. Tasks requiring high arm elevations (e.g. reaching at shoulder and overhead height) activated anterior supraspinatus between 21 and 28% MVC. The posterior supraspinatus consistently activated between 10 and 30% MVC across all tasks. All sub-regions of infraspinatus activated highly (between 18 and 25% MVC) in tasks requiring high arm elevations in flexion. These findings may be leveraged to define effective measures to increase rotator cuff function in daily tasks.
Collapse
Affiliation(s)
- Tea Lulic-Kuryllo
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Talia Alenabi
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Alison C McDonald
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Soo Y Kim
- University of Saskatchewan, College of Medicine, School of Rehabilitation Science, Saskatoon, Saskatchewan, Canada
| | - Clark R Dickerson
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.
| |
Collapse
|
9
|
Cudlip AC, Kim SY, Dickerson CR. The ability of surface electromyography to represent supraspinatus anterior and posterior partition activity depends on elevation angle, hand load and plane of elevation. J Biomech 2020; 99:109526. [PMID: 31780125 DOI: 10.1016/j.jbiomech.2019.109526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 11/11/2019] [Accepted: 11/14/2019] [Indexed: 10/25/2022]
Abstract
This study examined relationships between electromyography recorded from indwelling electrodes of the anterior and posterior supraspinatus and a surface supraspinatus electrode. Twenty male and twenty female participants completed full range humeral elevations in three planes of elevation (0/40/90°) and three hand loads (unloaded/20%/40% of maximal elevation strength). EMG activation was combined with motion capture to determine activation at instantaneous activation angles, and linear regressions of anterior and posterior indwelling electrodes relative to the surface electrode determined relationships between these signals. Regressions between surface and indwelling signals were affected by plane of elevation, elevation angle, load intensity and participant sex, but no interactions existed. Surface signals underestimated activation at low elevation angles for both regions, and up to 45% in the anterior supraspinatus (p < 0.01), then overestimated activation at higher elevation angles. Surface EMG underestimated indwelling signals by up to 15% in unloaded conditions, while overestimating the posterior region by up to 17% in the 40% load condition (p < 0.01). Sex effects showed increased overestimation by surface signals in the posterior region in males by 21% (p < 0.01). Better agreement existed for the anterior region than the posterior region across postures, but postural relationships should be considered when choosing electrodes for this muscle.
Collapse
Affiliation(s)
- Alan C Cudlip
- Department of Kinesiology, University of Waterloo, Waterloo, Canada
| | - Soo Y Kim
- School of Rehabilitation Science, University of Saskatchewan, Saskatoon, Canada.
| | - Clark R Dickerson
- Department of Kinesiology, University of Waterloo, Waterloo, Canada.
| |
Collapse
|
10
|
Calver R, Alenabi T, Cudlip A, Dickerson CR, Mondal P, Kim SY. Regional activation of supraspinatus and infraspinatus sub-regions during dynamic tasks performed with free weights. J Electromyogr Kinesiol 2019; 62:102308. [PMID: 31109772 DOI: 10.1016/j.jelekin.2019.05.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 05/02/2019] [Accepted: 05/10/2019] [Indexed: 11/18/2022] Open
Abstract
Growing evidence supports the existence of distinct anatomical sub-regions within supraspinatus and infraspinatus, but only recently has attention turned to exploring their potential functional differences. Using indwelling fine-wire electromyography, muscle activity was investigated from these sub-regions in 15 participants (mean 34 yr, 170 cm, 71.9 kg) during dynamic external rotation (ER), abduction, flexion, and scaption tasks with and without free weights corresponding to 50% and 75% of the participant's five repetition maximum. Electromyography data were normalized to isometric and isokinetic maximal voluntary contractions and activation ratios for each sub-region compared. Differences in mean regional activation ratios for supraspinatus and infraspinatus varied by arm posture, but were not influenced by load. Relative activation of posterior supraspinatus was greater during an ER task performed in side lying compared to an ER task performed with 90° of humeral elevation in seated and prone postures. Relative activation of superior infraspinatus was greater during an ER task in prone and side lying postures compared to flexion and scaption. Similar results were found when comparing regional muscle activation ratios for infraspinatus between tasks regardless of normalization method employed. These findings may impact exercise selection in the non-operative management of rotator cuff tears.
Collapse
Affiliation(s)
- Ronelle Calver
- McMaster University, Department of Medicine, Division of Physical Medicine and Rehabilitation, Hamilton, Ontario, Canada
| | - Talia Alenabi
- University of Waterloo, Faculty of Applied Health Sciences, Department of Kinesiology, Digital Industrial Ergonomics and Shoulder Evaluation Laboratory (DIESEL), Waterloo, Ontario, Canada
| | - Alan Cudlip
- University of Waterloo, Faculty of Applied Health Sciences, Department of Kinesiology, Digital Industrial Ergonomics and Shoulder Evaluation Laboratory (DIESEL), Waterloo, Ontario, Canada
| | - Clark R Dickerson
- University of Waterloo, Faculty of Applied Health Sciences, Department of Kinesiology, Digital Industrial Ergonomics and Shoulder Evaluation Laboratory (DIESEL), Waterloo, Ontario, Canada
| | - Prosanta Mondal
- University of Saskatchewan, College of Medicine, Department of Community Health and Epidemiology, Saskatoon, Saskatchewan, Canada
| | - Soo Y Kim
- University of Saskatchewan, College of Medicine, School of Rehabilitation Science, Saskatoon, Saskatchewan, Canada.
| |
Collapse
|