Considerations in Cervical Spine and Upper Limb Manual Muscle Testing: Difference between revisions

No edit summary
No edit summary
Line 7: Line 7:
Muscle strength plays an essential role in facilitating stability and mobility within the musculoskeletal system. Assessing muscle strength is an essential component of the physical examination, providing an objective measure of a patient's physical strength and offering valuable insights into potential neurological deficits.
Muscle strength plays an essential role in facilitating stability and mobility within the musculoskeletal system. Assessing muscle strength is an essential component of the physical examination, providing an objective measure of a patient's physical strength and offering valuable insights into potential neurological deficits.


During the strength assessment, clinicians should consider various factors that can influence the results, including the patient's occupation, hand dominance, age, biological sex, fatigue, medication, and the time of day. Accounting for these variables is essential to ensure accurate muscle strength evaluations.
During the strength assessment, clinicians should consider various factors that can influence the results, including hand dominance, age, biological sex, fatigue, medication, time of day and the patient's occupation. Accounting for these variables is essential to ensure accurate muscle strength evaluations.


If you would like a detailed discussion of the muscle strength assessment, please see: [[Assessing Muscle Strength]].
If you would like a detailed discussion of the muscle strength assessment, please see: [[Assessing Muscle Strength]].


== Occupation ==
== Hand Dominance ==
Occupation can play a role in shaping muscle strength. Different job requirements and physical demands can influence muscular development, function, and health. Research has demonstrated variations in static muscular strength across diverse occupations.<ref name=":1">Chandra AM, Ghosh S, Iqbal R, Sadhu N. [https://www.tandfonline.com/doi/pdf/10.1080/10803548.2007.11076727 A Comparative Assessment of the Impact of Different Occupations on Workers’ Static Musculoskeletal Fitness.] International Journal of Occupational Safety and Ergonomics. 2007 Jan;13(3):271-8.</ref>
Hand-grip strength is considered an indicator of overall strength and a predictor of key outcomes.<ref name=":2" /> For instance, low grip strength has been linked to chronic cardiometabolic diseases, neural conditions, reduced functional and mobility limitations.<ref>McGrath R, Johnson N, Klawitter L, Mahoney S, Trautman K, Carlson C, et al. [https://journals.sagepub.com/doi/full/10.1177/2050312120910358 What are the association patterns between handgrip strength and adverse health conditions? A topical review]. SAGE Open Med. 2020 Feb 28;8:2050312120910358. </ref>  


* Chandra et al.<ref name=":1" /> found that back strength was significantly lower in video display terminal operators, higher in safety inspectors and moderate in industrial workers, but grip and pinch strength in video display terminal operators, safety inspectors and industrial workers were similar<ref name=":1" />
When assessing healthy individuals, it is important to note that the grip strength of the dominant hand is approximately 10% greater than that of the nondominant hand. This difference is more pronoucned in individuals who are right-handed.<ref name=":2">Wang YC, Bohannon RW, Li X, Sindhu B, Kapellusch J. Hand-Grip Strength: [https://www.jospt.org/doi/10.2519/jospt.2018.7851 Normative Reference Values and Equations for Individuals 18 to 85 Years of Age Residing in the United States.] Journal of Orthopaedic & Sports Physical Therapy. 2018 Aug 31;48(9):685-93.</ref>
* Singh et al.<ref>Singh AK, Meena ML, Chaudhary H, Dangayach GS. [https://research.vit.ac.in/publication/a-comparative-assessment-of-static-muscular-strength-among-female/pdf/postprint-a-comparative-assessment-of-static-muscular-strength-among-female.pdf A comparative assessment of static muscular strength among female operative’s working in different handicraft occupations in India.] Health Care for Women International. 2018 Dec 20;40(4):459-78.</ref> found that female handicraft workers might experience higher occupational strength, resulting in decreased grip strength compared to their counterparts in office-based roles
* Hajaghazadeh et al.<ref>Hajaghazadeh M, Taghizadeh M, Mohebbi I, Khalkhali H. Hand anthropometric dimensions and strengths in workers: A comparison of three occupations. Human Factors and Ergonomics in Manufacturing and Service Industries. 2022;32:373-88.</ref> compared the hand anthropometric dimensions and hand strength of office workers, vehicle mechanics, and farmers and found that office workers had the weakest hand strength
 
These articles highlight the nuanced relationship between occupation and muscle strength, and emphasise the importance of considering job-specific demands when assessing muscle strength.
 
== Hand Dominance ==
In healthy individuals, the grip strength of the dominant hand is approximately 10% greater than that of the nondominant hand, with right-handed individuals exhibiting more pronounced differences.<ref>Wang YC, Bohannon RW, Li X, Sindhu B, Kapellusch J. Hand-Grip Strength: [https://www.jospt.org/doi/10.2519/jospt.2018.7851 Normative Reference Values and Equations for Individuals 18 to 85 Years of Age Residing in the United States.] Journal of Orthopaedic & Sports Physical Therapy. 2018 Aug 31;48(9):685–93.</ref>


== Age ==
== Age ==
As individuals age, there is a notable decline in muscular strength, with losses occurring at a rate of approximately 12% to 14% per decade after reaching 50 years of age.<ref>Volaklis KA, Halle M, Meisinger C. Muscular strength as a strong predictor of mortality: A narrative review. European Journal of Internal Medicine [Internet]. 2015 Jun 1;26(5):303–10</ref> Given this [[Muscle Function: Effects of Aging|age-related decline]], health authorities must consider the implementation of strength tests, such as hand grip and leg strength assessments, as screening activities to predict the potential risk of falls and the development of functional disabilities among older adults in the community.<ref>Wickramarachchi B, Torabi MR, Perera B. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9969476/ Effects of Physical Activity on Physical Fitness and Functional Ability in Older Adults.] Gerontology and Geriatric Medicine. 2023 Feb 23;9:233372142311584.</ref>
As individuals age, there is a notable decline in muscle strength, with losses occurring at a rate of approximately 12-14% per decade after the age of 50 years.<ref>Volaklis KA, Halle M, Meisinger C. Muscular strength as a strong predictor of mortality: A narrative review. European Journal of Internal Medicine [Internet]. 2015 Jun 1;26(5):303–10</ref>  


* [[Sarcopenia]], a progressive and generalised skeletal muscle disorder, is linked to a heightened risk of adverse outcomes such as falls, fractures, physical disability, and mortality<ref>Cruz-Jentoft AJ, Bahat G, Bauer J, Boirie Y, Bruyère O, Cederholm T, et al. [https://academic.oup.com/ageing/article/48/1/16/5126243?login=false Sarcopenia: Revised European Consensus on Definition and Diagnosis.] Age and Ageing. 2018 Sep 24;48(1):16–31. </ref>
* Soares et al.<ref name=":3">Soares LA, Lima LP, Prates ACN, et al. [https://www.nature.com/articles/s41598-023-28549-5 Accuracy of handgrip and respiratory muscle strength in identifying sarcopenia in older, community-dwelling, Brazilian women.] Bone. 2023 Jan 27;13(1).</ref> found that older, community-dwelling women living in Brazil who have sarcopenia had lower handgrip strength and respiratory muscle strength compared to their peers who did not have sacropenia<ref name=":3" />


[[Sarcopenia]], a progressive and generalised skeletal muscle disorder, is linked to a heightened risk of adverse outcomes such as falls, fractures, physical disability, and mortality.<ref>Cruz-Jentoft AJ, Bahat G, Bauer J, Boirie Y, Bruyère O, Cederholm T, et al. [https://academic.oup.com/ageing/article/48/1/16/5126243?login=false Sarcopenia: Revised European Consensus on Definition and Diagnosis.] Age and Ageing. 2018 Sep 24;48(1):16–31. </ref>  A study done by Soares et al. (2023) in older, community-dwelling, Brazilian women, indicates that individuals with sarcopenia exhibit lower handgrip strength and respiratory muscle strength compared to their non-sarcopenic counterparts among the elderly.<ref>Soares LA, Lima LP, Prates ACN, et al. [https://www.nature.com/articles/s41598-023-28549-5 Accuracy of handgrip and respiratory muscle strength in identifying sarcopenia in older, community-dwelling, Brazilian women.] Bone. 2023 Jan 27;13(1).</ref>
Given these [[Muscle Function: Effects of Aging|age-related changes]], health authorities should consider implementing strength tests, such as hand grip and leg strength assessments, as screening activities to predict the potential risk of falls and the development of functional disabilities among older adults in the community.<ref>Wickramarachchi B, Torabi MR, Perera B. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9969476/ Effects of Physical Activity on Physical Fitness and Functional Ability in Older Adults.] Gerontology and Geriatric Medicine. 2023 Feb 23;9:233372142311584.</ref>  


The following video provides information on aging and muscle mass.
Please watch the following video if you would like to learn more about ageing and muscle mass.


{{#ev:youtube|WG8Slgc36KI|500}}
{{#ev:youtube|WG8Slgc36KI|500}}


== Gender ==
== Biological Sex ==
Males consistently exhibit superior mechanical muscle function compared to females regardless of age, as evidenced by various measures.<ref>Elam C, Aagaard P, Slinde F, Svantesson U, Hulthén L, Magnusson PS, et al. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8012187/ The effects of ageing on functional capacity and stretch-shortening cycle muscle power.] Journal of Physical Therapy Science. 2021 Mar 17;33(3):250–60.</ref>
Biological males consistently exhibit superior mechanical muscle function compared to females regardless of age, as evidenced by various measures.<ref>Elam C, Aagaard P, Slinde F, Svantesson U, Hulthén L, Magnusson PS, et al. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8012187/ The effects of ageing on functional capacity and stretch-shortening cycle muscle power.] Journal of Physical Therapy Science. 2021 Mar 17;33(3):250–60.</ref> In adult populations, these diffrences in strength are more pronounced in upper-body muscles than lower-body muscles, and in concentric contractions compared to eccentric contractions. This difference is primarily attributed to the presence of greater muscle mass and larger type II fibre areas in biological males.<ref>Nuzzo JL. [https://journals.lww.com/nsca-jscr/fulltext/2023/02000/narrative_review_of_sex_differences_in_muscle.28.aspx Narrative Review of Sex Differences in Muscle Strength, Endurance, Activation, Size, Fiber Type, and Strength Training Participation Rates, Preferences, Motivations, Injuries, and Neuromuscular Adaptations.] Journal of Strength and Conditioning Research. 2022 Nov 15;37(2):494–536.</ref>
 
Moreover, in adult populations, the disparities in strength between sexes are more prominent in upper-body muscles than lower-body muscles, and in concentric contractions compared to eccentric contractions. The observed greater strength in males cannot be solely attributed to higher voluntary activation; rather, it is primarily attributed to the presence of greater muscle mass and larger type II fibre areas.<ref>Nuzzo JL. [https://journals.lww.com/nsca-jscr/fulltext/2023/02000/narrative_review_of_sex_differences_in_muscle.28.aspx Narrative Review of Sex Differences in Muscle Strength, Endurance, Activation, Size, Fiber Type, and Strength Training Participation Rates, Preferences, Motivations, Injuries, and Neuromuscular Adaptations.] Journal of Strength and Conditioning Research. 2022 Nov 15;37(2):494–536.</ref>


The following video discusses sex differences in muscle strength.
The following optional video discusses differences in muscle strength between males and females.


{{#ev:youtube|GiAAGYPjQzw|500}}
{{#ev:youtube|GiAAGYPjQzw|500}}


== Fatigue ==
== Fatigue ==
The physiological underpinnings of [[Muscle Fatigue|muscle fatigue]] have been extensively studied, revealing that fatigue can stem from a myriad of mechanisms. The manifestation of muscle fatigue is commonly quantified by a decline in the maximal force or power capacity of the muscle, enabling the sustaining of submaximal contractions even after the onset of fatigue.<ref name=":0">Enoka RM, Duchateau J. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2375565/ Muscle Fatigue: What, Why and How It Influences Muscle Function.] The Journal of Physiology [Internet]. 2008 Jan 1;586(1):11–23.</ref>  
The physiological underpinnings of [[Muscle Fatigue|muscle fatigue]] have been extensively studied. It can be caused by a number of different processes, such as the accumulation of metabolites in muscle fibres or inadequate motor commands being generated in the motor cortex.<ref name=":0">Enoka RM, Duchateau J. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2375565/ Muscle Fatigue: What, Why and How It Influences Muscle Function.] The Journal of Physiology [Internet]. 2008 Jan 1;586(1):11–23.</ref> <blockquote>"The development of muscle fatigue is typically quantified as a decline in the maximal force or power capacity of muscle, which means that submaximal contractions can be sustained after the onset of muscle fatigue."<ref name=":0" /> </blockquote>The impact of fatigue on muscle function is profound. As soon as a muscle's maximal force or power capacity begins to decline, the muscle enters a state of fatigue. When a task involves sustaining a maximal contraction, the decline in performance mirrors the escalation of fatigue.<ref name=":0" />
 
Yanez et al.<ref name=":4">Yanez C, Ochoa N, Cardozo L, Jhonatan Peña, Diaz N, Ojeda W, et al. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10124738/ Assessment of Neuromuscular Fatigue 24 hours After a Futsal Simulated Protocol in University Female Athletes.] PubMed. 2023 Feb 1;16(1):205–16.</ref> compared neuromuscular performance changes in young female university athletes before and after a simulated futsal protocol. They found that changes in neuromuscular performace variables following a futsal simulation protocol resulted in a state of residual muscle fatigue the day after the intervention.<ref name=":4" /> These findings shed light on the enduring effects of demanding interventions / exercise on neuromuscular performance and highlight the importance of considering residual fatigue in post-intervention assessments.
== Medication ==
Many medications prescribed for commonly occuring conditions can interact with physiological mechanisms, consequently influencing the delicate equilibrium between protein synthesis and degradation. Such interactions can have both positive and negative effects on muscle mass and strength.<ref>Campins L, Camps M, Riera A, Pleguezuelos E, Yebenes JC, Serra-Prat M. O[https://karger.com/pha/article-pdf/99/1-2/1/3424733/000448247.pdf ral Drugs Related with Muscle Wasting and Sarcopenia. A Review. Pharmacology.] 2016 Aug 31;99(1-2):1–8.</ref> Thus, clinicians should also determine what medications a patient is taking and consider their impact when assessing muscle strength.


The influence of fatigue on muscle function is profound. As soon as a muscle's maximal force or power capacity begins to decline, it enters a state of fatigue. Notably, when the task involves sustaining a maximal contraction, the decline in performance mirrors the escalation of fatigue.<ref name=":0" />  
== Time of Day ==
Research has consistently revealed diurnal variations in skeletal muscle strength, with peak strength typically observed during the late afternoon (i.e. at around 16:00-20:00 / 4-8pm). This phenomenon occurs in various muscle groups, ranging from the smaller muscles involved in grip strength to the larger muscle groups involved in elbow and knee strength. The underlying mechanisms driving these changes in strength throughout the day are still not well defined.<ref>Douglas CM, Hesketh SJ, Esser KA. [https://journals.physiology.org/doi/full/10.1152/physiol.00030.2020?rfr_dat=cr_pub++0pubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org Time of Day and Muscle Strength: A Circadian Output?] Physiology. 2020 Dec 16;36(1):44–51.</ref>


Furthermore, studies have confirmed the hypothesis regarding the changes in neuromuscular performance variables following the application of simulation protocols, establishing a state of residual fatigue during the day following the intervention.<ref>Yanez C, Ochoa N, Cardozo L, Jhonatan Peña, Diaz N, Ojeda W, et al. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10124738/ Assessment of Neuromuscular Fatigue 24 hours After a Futsal Simulated Protocol in University Female Athletes.] PubMed. 2023 Feb 1;16(1):205–16.</ref> These findings shed light on the enduring effects of specific interventions on neuromuscular performance, highlighting the importance of considering residual fatigue in post-intervention assessments.
== Occupation ==
Occupation can play a role in shaping muscle strength. Different job requirements and physical demands can influence muscular development, function, and health. Research has demonstrated variations in static muscular strength across diverse occupations.<ref name=":1">Chandra AM, Ghosh S, Iqbal R, Sadhu N. [https://www.tandfonline.com/doi/pdf/10.1080/10803548.2007.11076727 A Comparative Assessment of the Impact of Different Occupations on Workers’ Static Musculoskeletal Fitness.] International Journal of Occupational Safety and Ergonomics. 2007 Jan;13(3):271-8.</ref>


== Medication ==
* Chandra et al.<ref name=":1" /> found that back strength was significantly lower in video display terminal operators, higher in safety inspectors and moderate in industrial workers, but grip and pinch strength in video display terminal operators, safety inspectors and industrial workers were similar<ref name=":1" />
Numerous commonly prescribed medications for prevalent conditions have the potential to interact with physiological mechanisms, consequently influencing the delicate equilibrium between protein synthesis and degradation. Such interactions may yield either detrimental or advantageous effects on muscle mass and strength,<ref>Campins L, Camps M, Riera A, Pleguezuelos E, Yebenes JC, Serra-Prat M. O[https://karger.com/pha/article-pdf/99/1-2/1/3424733/000448247.pdf ral Drugs Related with Muscle Wasting and Sarcopenia. A Review. Pharmacology.] 2016 Aug 31;99(1-2):1–8.</ref> underscoring the significance of considering medication-related impacts when assessing muscle strength.
* Singh et al.<ref>Singh AK, Meena ML, Chaudhary H, Dangayach GS. [https://research.vit.ac.in/publication/a-comparative-assessment-of-static-muscular-strength-among-female/pdf/postprint-a-comparative-assessment-of-static-muscular-strength-among-female.pdf A comparative assessment of static muscular strength among female operative’s working in different handicraft occupations in India.] Health Care for Women International. 2018 Dec 20;40(4):459-78.</ref> found that female handicraft workers might experience higher occupational strength, resulting in decreased grip strength compared to their counterparts in office-based roles
* Hajaghazadeh et al.<ref>Hajaghazadeh M, Taghizadeh M, Mohebbi I, Khalkhali H. Hand anthropometric dimensions and strengths in workers: A comparison of three occupations. Human Factors and Ergonomics in Manufacturing and Service Industries. 2022;32:373-88.</ref> compared the hand anthropometric dimensions and hand strength of office workers, vehicle mechanics, and farmers and found that office workers had the weakest hand strength


== Time of Day ==
These articles highlight the nuanced relationship between occupation and muscle strength, and emphasise the importance of considering job-specific demands when assessing muscle strength.
Research has consistently revealed diurnal variations in skeletal muscle strength, with peak strength typically observed during the late afternoon, around 16:00–20:00. This phenomenon has been substantiated across various muscle groups, ranging from the smaller muscles involved in grip strength to the upper limb and large muscle groups governing elbow and knee strength, respectively. Despite the robust nature of these fluctuations in muscle strength throughout the day, the underlying mechanisms driving this circadian physiology remain inadequately characterised to date.<ref>Douglas CM, Hesketh SJ, Esser KA. [https://journals.physiology.org/doi/full/10.1152/physiol.00030.2020?rfr_dat=cr_pub++0pubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org Time of Day and Muscle Strength: A Circadian Output?] Physiology. 2020 Dec 16;36(1):44–51.</ref>


== Summary ==
== Summary ==
The assessment of cervical spine and upper limb manual muscle testing is a complex process influenced by various factors such as occupation-related stress, hand dominance, age, gender, fatigue, medication, and time of day. These elements significantly impact muscle strength testing outcomes. The age-related decline in muscular strength highlights the importance of using strength tests as screening activities for predicting the risk of falls and functional disabilities in older adults. Disparities in strength between sexes, the influence of fatigue on muscle function, and potential medication interactions further complicate muscle strength assessment. Moreover, the diurnal variations in skeletal muscle strength, with peak strength in the late afternoon, require consideration, despite the inadequate understanding of the underlying mechanisms. These collective findings emphasise the necessity of a comprehensive and nuanced approach to the cervical spine and upper limb manual muscle testing, recognising the diverse array of factors that influence muscle strength assessment in clinical and research settings.
Clinicians must remember that the strength of the cervical spine and upper limb muscles can be influenced by various factors such as hand dominance, age, gender, fatigue, medication, time of day and the patient's occupation. These elements significantly impact muscle strength testing outcomes and must be considered when conducting a strength assessment.  


== References  ==
== References  ==

Revision as of 00:24, 20 March 2024

Original Editor - Lenie Jacobs

Top Contributors - Lenie Jacobs and Jess Bell  

Introduction[edit | edit source]

Muscle strength plays an essential role in facilitating stability and mobility within the musculoskeletal system. Assessing muscle strength is an essential component of the physical examination, providing an objective measure of a patient's physical strength and offering valuable insights into potential neurological deficits.

During the strength assessment, clinicians should consider various factors that can influence the results, including hand dominance, age, biological sex, fatigue, medication, time of day and the patient's occupation. Accounting for these variables is essential to ensure accurate muscle strength evaluations.

If you would like a detailed discussion of the muscle strength assessment, please see: Assessing Muscle Strength.

Hand Dominance[edit | edit source]

Hand-grip strength is considered an indicator of overall strength and a predictor of key outcomes.[1] For instance, low grip strength has been linked to chronic cardiometabolic diseases, neural conditions, reduced functional and mobility limitations.[2]

When assessing healthy individuals, it is important to note that the grip strength of the dominant hand is approximately 10% greater than that of the nondominant hand. This difference is more pronoucned in individuals who are right-handed.[1]

Age[edit | edit source]

As individuals age, there is a notable decline in muscle strength, with losses occurring at a rate of approximately 12-14% per decade after the age of 50 years.[3]

  • Sarcopenia, a progressive and generalised skeletal muscle disorder, is linked to a heightened risk of adverse outcomes such as falls, fractures, physical disability, and mortality[4]
  • Soares et al.[5] found that older, community-dwelling women living in Brazil who have sarcopenia had lower handgrip strength and respiratory muscle strength compared to their peers who did not have sacropenia[5]

Given these age-related changes, health authorities should consider implementing strength tests, such as hand grip and leg strength assessments, as screening activities to predict the potential risk of falls and the development of functional disabilities among older adults in the community.[6]

Please watch the following video if you would like to learn more about ageing and muscle mass.

Biological Sex[edit | edit source]

Biological males consistently exhibit superior mechanical muscle function compared to females regardless of age, as evidenced by various measures.[7] In adult populations, these diffrences in strength are more pronounced in upper-body muscles than lower-body muscles, and in concentric contractions compared to eccentric contractions. This difference is primarily attributed to the presence of greater muscle mass and larger type II fibre areas in biological males.[8]

The following optional video discusses differences in muscle strength between males and females.

Fatigue[edit | edit source]

The physiological underpinnings of muscle fatigue have been extensively studied. It can be caused by a number of different processes, such as the accumulation of metabolites in muscle fibres or inadequate motor commands being generated in the motor cortex.[9]

"The development of muscle fatigue is typically quantified as a decline in the maximal force or power capacity of muscle, which means that submaximal contractions can be sustained after the onset of muscle fatigue."[9]

The impact of fatigue on muscle function is profound. As soon as a muscle's maximal force or power capacity begins to decline, the muscle enters a state of fatigue. When a task involves sustaining a maximal contraction, the decline in performance mirrors the escalation of fatigue.[9]

Yanez et al.[10] compared neuromuscular performance changes in young female university athletes before and after a simulated futsal protocol. They found that changes in neuromuscular performace variables following a futsal simulation protocol resulted in a state of residual muscle fatigue the day after the intervention.[10] These findings shed light on the enduring effects of demanding interventions / exercise on neuromuscular performance and highlight the importance of considering residual fatigue in post-intervention assessments.

Medication[edit | edit source]

Many medications prescribed for commonly occuring conditions can interact with physiological mechanisms, consequently influencing the delicate equilibrium between protein synthesis and degradation. Such interactions can have both positive and negative effects on muscle mass and strength.[11] Thus, clinicians should also determine what medications a patient is taking and consider their impact when assessing muscle strength.

Time of Day[edit | edit source]

Research has consistently revealed diurnal variations in skeletal muscle strength, with peak strength typically observed during the late afternoon (i.e. at around 16:00-20:00 / 4-8pm). This phenomenon occurs in various muscle groups, ranging from the smaller muscles involved in grip strength to the larger muscle groups involved in elbow and knee strength. The underlying mechanisms driving these changes in strength throughout the day are still not well defined.[12]

Occupation[edit | edit source]

Occupation can play a role in shaping muscle strength. Different job requirements and physical demands can influence muscular development, function, and health. Research has demonstrated variations in static muscular strength across diverse occupations.[13]

  • Chandra et al.[13] found that back strength was significantly lower in video display terminal operators, higher in safety inspectors and moderate in industrial workers, but grip and pinch strength in video display terminal operators, safety inspectors and industrial workers were similar[13]
  • Singh et al.[14] found that female handicraft workers might experience higher occupational strength, resulting in decreased grip strength compared to their counterparts in office-based roles
  • Hajaghazadeh et al.[15] compared the hand anthropometric dimensions and hand strength of office workers, vehicle mechanics, and farmers and found that office workers had the weakest hand strength

These articles highlight the nuanced relationship between occupation and muscle strength, and emphasise the importance of considering job-specific demands when assessing muscle strength.

Summary[edit | edit source]

Clinicians must remember that the strength of the cervical spine and upper limb muscles can be influenced by various factors such as hand dominance, age, gender, fatigue, medication, time of day and the patient's occupation. These elements significantly impact muscle strength testing outcomes and must be considered when conducting a strength assessment.

References[edit | edit source]

  1. 1.0 1.1 Wang YC, Bohannon RW, Li X, Sindhu B, Kapellusch J. Hand-Grip Strength: Normative Reference Values and Equations for Individuals 18 to 85 Years of Age Residing in the United States. Journal of Orthopaedic & Sports Physical Therapy. 2018 Aug 31;48(9):685-93.
  2. McGrath R, Johnson N, Klawitter L, Mahoney S, Trautman K, Carlson C, et al. What are the association patterns between handgrip strength and adverse health conditions? A topical review. SAGE Open Med. 2020 Feb 28;8:2050312120910358.
  3. Volaklis KA, Halle M, Meisinger C. Muscular strength as a strong predictor of mortality: A narrative review. European Journal of Internal Medicine [Internet]. 2015 Jun 1;26(5):303–10
  4. Cruz-Jentoft AJ, Bahat G, Bauer J, Boirie Y, Bruyère O, Cederholm T, et al. Sarcopenia: Revised European Consensus on Definition and Diagnosis. Age and Ageing. 2018 Sep 24;48(1):16–31.
  5. 5.0 5.1 Soares LA, Lima LP, Prates ACN, et al. Accuracy of handgrip and respiratory muscle strength in identifying sarcopenia in older, community-dwelling, Brazilian women. Bone. 2023 Jan 27;13(1).
  6. Wickramarachchi B, Torabi MR, Perera B. Effects of Physical Activity on Physical Fitness and Functional Ability in Older Adults. Gerontology and Geriatric Medicine. 2023 Feb 23;9:233372142311584.
  7. Elam C, Aagaard P, Slinde F, Svantesson U, Hulthén L, Magnusson PS, et al. The effects of ageing on functional capacity and stretch-shortening cycle muscle power. Journal of Physical Therapy Science. 2021 Mar 17;33(3):250–60.
  8. Nuzzo JL. Narrative Review of Sex Differences in Muscle Strength, Endurance, Activation, Size, Fiber Type, and Strength Training Participation Rates, Preferences, Motivations, Injuries, and Neuromuscular Adaptations. Journal of Strength and Conditioning Research. 2022 Nov 15;37(2):494–536.
  9. 9.0 9.1 9.2 Enoka RM, Duchateau J. Muscle Fatigue: What, Why and How It Influences Muscle Function. The Journal of Physiology [Internet]. 2008 Jan 1;586(1):11–23.
  10. 10.0 10.1 Yanez C, Ochoa N, Cardozo L, Jhonatan Peña, Diaz N, Ojeda W, et al. Assessment of Neuromuscular Fatigue 24 hours After a Futsal Simulated Protocol in University Female Athletes. PubMed. 2023 Feb 1;16(1):205–16.
  11. Campins L, Camps M, Riera A, Pleguezuelos E, Yebenes JC, Serra-Prat M. Oral Drugs Related with Muscle Wasting and Sarcopenia. A Review. Pharmacology. 2016 Aug 31;99(1-2):1–8.
  12. Douglas CM, Hesketh SJ, Esser KA. Time of Day and Muscle Strength: A Circadian Output? Physiology. 2020 Dec 16;36(1):44–51.
  13. 13.0 13.1 13.2 Chandra AM, Ghosh S, Iqbal R, Sadhu N. A Comparative Assessment of the Impact of Different Occupations on Workers’ Static Musculoskeletal Fitness. International Journal of Occupational Safety and Ergonomics. 2007 Jan;13(3):271-8.
  14. Singh AK, Meena ML, Chaudhary H, Dangayach GS. A comparative assessment of static muscular strength among female operative’s working in different handicraft occupations in India. Health Care for Women International. 2018 Dec 20;40(4):459-78.
  15. Hajaghazadeh M, Taghizadeh M, Mohebbi I, Khalkhali H. Hand anthropometric dimensions and strengths in workers: A comparison of three occupations. Human Factors and Ergonomics in Manufacturing and Service Industries. 2022;32:373-88.