Considerations in Cervical Spine and Upper Limb Manual Muscle Testing
Original Editor - Lenie Jacobs
Top Contributors - Lenie Jacobs and Jess Bell
Introduction[edit | edit source]
Muscle strength stands as a cornerstone of the human body's ability to facilitate both stability and mobility within the musculoskeletal system. As an essential component of the objective examination, the assessment of muscle strength not only sheds light on an individual's physical strength but also offers valuable insights into potential neurological deficits.
When assessing muscle strength, one should consider various factors that can influence the results, including occupation, hand dominance, age, gender, fatigue, medication, and the time of day. These elements can impact muscle strength testing and should be carefully accounted for during the evaluation process.
Occupation[edit | edit source]
Research has demonstrated substantial variations in static muscular strength across diverse occupations.[1] Additionally, findings from a study by Singh et al. (2018) suggest that female handicraft workers may experience occupational stress, resulting in decreased grip strength compared to their counterparts in office-based roles.[2]
Hand Dominance[edit | edit source]
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.[3]
Age[edit | edit source]
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.[4] Given this 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.[5]
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.[6] 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.[7]
The following video provides information on aging and muscle mass.
Gender[edit | edit source]
Males consistently exhibit superior mechanical muscle function compared to females regardless of age, as evidenced by various measures.[8]
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.[9]
The following video discusses sex differences in muscle strength.
Fatigue[edit | edit source]
The physiological underpinnings of 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.[10]
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.[10]
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.[11] 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.
Medication[edit | edit source]
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,[12] underscoring the significance of considering medication-related impacts 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, 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.[13]
Summary[edit | edit source]
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.
References[edit | edit source]
- ↑ 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.
- ↑ 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
- ↑ 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.
- ↑ 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
- ↑ 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.
- ↑ 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.
- ↑ 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).
- ↑ 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.
- ↑ 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.
- ↑ 10.0 10.1 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.
- ↑ 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.
- ↑ 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.
- ↑ Douglas CM, Hesketh SJ, Esser KA. Time of Day and Muscle Strength: A Circadian Output? Physiology. 2020 Dec 16;36(1):44–51.
