Daniels scale: what it is, characteristics and functions

The Daniels Scale or Daniels Test is a tool used to measure muscle strength in the human body, especially in patients with neuromuscular disorders or localized injuries.

We must keep in mind that the muscular system allows us to relate to the environment, as it is responsible for movement, and therefore responsible for adapting our body to the immediate spatial demands of the environment around us. This is why humans have 650 different muscles, which corresponds to 40% of the weight of an adult individual, a significant figure.

Therefore, the evaluation of the muscle strength of patients in the context of physiotherapy treatments is an essential question. In addition to identifying and tracking disease progression, scales such as Daniels can be useful for cultural events, as they allow for the assessment of, for example, participants in Paralympic sports.

For all the important reasons we have outlined above, here we have explained to you what the Daniels scale is and in which areas it applies.

    Daniels scale: classify muscle strength

    As we said before, this scale and others are used to measure the strength of muscles in the human body. Since we don’t want to start building the house on the roof, we first need to cement, at least succinctly, what muscle strength is and how it works.

    About muscle strength

    Muscle strength is defined as the ability of a muscle or series of muscles to exert tension against a load during a muscle contraction exercise. As simple as this definition of “book” may be, several sources claim that muscle strength can be dissected into three different variations:

    • Maximum strength: The highest force value that the neuromuscular system can show during a contraction.
    • Explosive force: the achievement of the maximum degree of force possible in a minimum time interval.
    • Endurance strength: it is the endurance capacity of a certain muscle group when a constant and long force effort is made.

    As we can see, we are ahead muscular efforts cataloged according to their resistance, their duration and their speed of execution. Each of these types of forces has uses at specific times in an individual’s life and in various sports.

    Muscle tension can be performed isotonically or isometrically and there are three types of muscle contractions (agonists, antagonists and synergists). While we will not dwell on this complex terminology due to the risk of straying too far from the topic at hand, we are throwing out the terms so that the conceptual world that shuts down muscle strength remains in effect.

    A digital scale

    Coming back to the subject that belongs to us here, the Daniels scale first published in 1946 and was written by Americans Lucille Daniels, Marian Williams and Catherine Worthingham (Hence, in English it is also known as the “Daniels and Worthingham Scale”). The book, known as “Muscle Functional Tests: Manual Scanning Techniques” is still available today, both in online format and on sales portals for all knowledge.

    The scale itself follows specific numbering, With six well differentiated levels from 0 to 5. These are:

    • 0: the muscle does not contract, complete paralysis.
    • 1: the muscle contracts, but there is no movement. The contraction can be palpated or visualized, but there is no movement.
    • 2: The muscle contracts and does all the movement, but without resistance because it cannot overcome gravity.
    • 3: The muscle can perform the movement against gravity as the only resistance.
    • 4: The muscle contracts and performs the full movement, in all its amplitude, against gravity and against moderate manual resistance.
    • 5: the muscle contracts and performs the movement in its full amplitude against gravity and with maximum manual resistance.

    This numerical scale is accompanied by a qualitative evaluation, which assigns the parameters “Normal”, “Good”; “Regular”, “Deficient”, “Activity Traces” and “Null” to the previously named values.

    The division of this scale, mentioned word for word, allows physiotherapists to assess the ability of a muscle to generate a contraction, Which leads to making a movement, maintaining it or slowing it down.

    However, in some cases the patient’s strength is a biased parameter, as the patient may be variable (eg, having the individual exert less force than he is actually capable of) and subjective. On these occasions, other more sophisticated tools are needed.

    Electromyography is an example, A technique for graphically recording the electrical activity produced by skeletal muscles. We no longer rely on a simple observation, the electromyogram being obtained from the insertion of electrodes on the muscular or skin surface which is located above.

    It is important to recognize that the Daniels Scale is part of a comprehensive assessment of the patient’s neuromuscular condition, but does not in any way provide answers to all of the variables to be measured.

    This test illustrates both strength and muscle function, however other parameters such as the following should also be taken into account: Arcs of motion (observation of active and passive movements), balance and stability (observation of motor responses) and assessment of patient coordination and gait (using eye tests, eye tests and observation) .

    In addition, it has certain reservations: above all, sections 4 to 5 of the scale are partially subjectiveAs they are very dependent on the examiner and on the force that the examiner applies to the member to be evaluated. This has led several professionals to categorize this type of scale as an insensitive and not very valid method, due to a strong load of uncontrollable subjectivity.

      Application of muscle strength tests

      Neuromuscular diseases are a set of more than 150 neurological pathologies, for the most part of an evolutionary nature and of genetic originThe main feature is the loss of muscle strength. Although they are considered serious illnesses, it is estimated that today more than 60,000 people are affected by this type of disorder in Spain alone.

      More than 50% of these diseases appear during childhood, and unfortunately, they still do not have effective treatments or cures, even if their detection in time allows the application of different therapies to alleviate the symptoms. In addition to a loss of mobility which generates a variable degree of incapacity in the individual, the loss of personal autonomy and the inability to achieve self-fulfillment have various psychosocial effects on the patient.

      For all these reasons, Quickly identifying these disorders becomes essential to deal with them in a multidisciplinary manner. (Both in a medical and psychological field). The performance of tests such as those of the Daniels scale is a suitable basis for the detection of various diseases or for the quantification of damage caused after a traumatic event to the nervous system.

      It is not all reduced to genetic diseases, for example, there may be loss of muscle strength after a stroke, damage to brain mass, trauma to the spine and many other pathologies. In this case, it is an acquired muscle disorder, as there is no apparent genetic predisposition on the part of the individual to suffer from it.


      As we have seen, muscle strength tests or manual muscle tests (MMT) are a series of relatively useful tools for assessing the condition of a patient’s muscles at any given time.

      If its relative effectiveness is well established, these practices should be combined with more effective and more efficient methods. objectives., Such as electromyography, strain gauge or dynamometry, in addition to gauges many other parameters not directly associated with muscle strength itself.

      The Daniels scale has several advantages, due to the simple cataloging of the patient on the basis of a numerical score, but it is questioned for certain reasons, such as the strong subjective component of the rater in question. Of course, with the amount of tools available today, observation-based assessment may not be the only medium for diagnosis.

      Bibliographical references:

      • Ciesla, N., Dinglas, V., Fan, E., Kho, M., Kuramoto, J. and Needham, D. (2011). Manual muscle testing: a method of measuring limb muscle strength applied to critically ill patients. JoVE (Journal of Visualized Experiments), (50), e2632.
      • Hislop, HJ and Montgomery, J. (2002). Examination of the muscles of the upper limb. Muscle functional tests. Madrid: Marbán Llibres, 4, 57-166.
      • Montoya-Leal, V., and Pérez, VZ (2016). Quantitative evaluation for professional reintegration. Uninorte Health Magazine, 32 (2), 319-336.
      • Mora, IS (2000). Muscular system.
      • Daniels, L. and Worthingham, C. (1973). Muscle functional tests – Manual expression techniques.
      • Tweedy, SM, Williams, G. and Bourke, J. (2010). Selection and modification of manual muscle testing methods for classification in Paralympic sports. European Journal of Adapted Physical Activity, 3 (2), 7-16.
      • What are Muscle Diseases? Aesem.org. Collected September 10 from https://www.asem-esp.org/que-son-las-enm/

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