2. Home
  3. Journal Issues
  4. Journal issue Volume 4 №2 for 2025
  5. Gromyko M.V., Bajguzhin P.A. Development of an interval dynamometric functional test

Gromyko M.V., Bajguzhin P.A. Development of an interval dynamometric functional test

Download the article in pdf format

Publication date: 15.06.2025
DOI: 10.24412/2782-6570-2025_04_02_1
UDC 612.817.2; 796.015.686

DEVELOPMENT OF AN INTERVAL DYNAMOMETRIC FUNCTIONAL TEST

M.V. Gromyko, P.A. Bajguzhin

South Ural State University (National Research University), Chelyabinsk, Russia

Abstract. An interval dynamometric functional test is proposed and tested, designed to assess the level of voluntary regulation of muscle effort implemented in the isometric mode. A brief overview shows an analysis of the factors that determine and influence the voluntary regulation of muscle effort. The target audience of this sample is professional climbers. The functional test is conducted in inpatient conditions of a laboratory in compliance with standard regulations and requirements to such observations. It is advisable to use a digital dynamometer, for example, the NS-Psychotest complex. The design of a functional test using an electronic dynamometer is presented.

Keywords: functional test, muscle effort, isometric muscle contraction, regulation, interval mode.

Introduction. Among factors defining physical (functional) fitness, muscle strength is a biological predictor of a state of health in the ontogenetic aspect. Moreover, in the practice of sports medicine and physiology, assessment of strength-related parameters is a criterion of effectiveness of restorative processes, as well as musculoskeletal, cardiovascular and neurological rehabilitation. 

In modern studies the assessment of such parameters is realized with a number of hardware and software complexes: Lafayette, Microfet 2, Fet 2 Hoggan Health Industries, GT-10, Biodex, J Tech et al. [1]. Dynamometry is an integral part of muscle function study when assessing performance of athletes [2, 3]. However the specificity of such method, aside from study tasks, is defined by features of a certain sport. A typical movement technique and its efficiency depend on how well the neuromuscular profile of an athlete is formed.

Regardless of many existing protocols of dynamometric studies, there is a number of specific factors, consideration of which increases reliability of isometric strength assessment: standardization (unification), content of instruction, degree of muscle pre-tension, position of body parts (e.g. limbs), joint angle, range of motion, types of stabilization and fixation; speed, testing sequence, rest intervals, feedback, etc. [4]. For example, it has been found that the reliability of isometric strength testing of upper and lower body muscles increases when they are repeated twice regardless of the gender of the subjects [5]. An analysis of the strength-time ratio and the frequency of surface electromyographic signals during the isometric hand grip test revealed the optimal duration of the test muscle tension – 10 seconds [6].

In addition, quality of measuring strength-related indicators depends also on age and gender peculiarities [7], body mass (composition in particular [8]) and length, as well as the level of fitness and motor asymmetry. Thus F. Pournasiri et al (2023) showed a negative effect of the follicular and luteal phases of the menstrual cycle on strength of knee flexor and extensor muscles, which is manifested in an increased risk of the anterior cruciate ligament injury [9].

At the same time, sources describe a number of neural, mechanical and methodological factors that negate the value of isometric strength assessment in the context of a holistic motor act, much less the dynamic characterization of locomotion and its series [10].

In the systematic review, based on the COSMIN standards (an initiative of an international interdisciplinary group of researchers with expertise in epidemiology, psychometrics, medicine, qualitative research and public health who have experience in developing and evaluating outcome measurement tools (https://www.cosmin.nl/)), only three of the 15 papers on dynamometric studies demonstrated satisfactory methodological quality. The low methodological quality of the studies is due to small sample size (less than 20); high variability in the observation time interval (from 1 minute to 14 days); lack of randomization [1].

Objective of the study: a development of a functional test – a dynamometric assessment of isometric strength of finger flexor muscles, implemented in the interval isometric mode (increase in the tension of contractile elements without detecting changes in muscle length or joint position). The target audience of this test is professional climbers.

Studies of strength performance in predominantly carpal dynamometry in climbers are few and are usually accompanied by the concurrent use of electromyography [11]; near-infrared spectroscopy [12] of the superficial finger flexor.

The climber study models are reduced to estimations of strength parameters during repeated isometric contractions of the finger flexor muscles. Thus, in the work of F. Quaine et al. (2003), the study protocol included repetition of holding muscle effort equal to 80% of the maximum isometric strength with 5-second breaks [11]. D. MacLeod et al. (2007) proposed an isometric endurance test at 40% of maximum isometric strength with repeated 10-second force holds with 3-second rests in between [12]. In the literature, the problem of validity and reliability of climbing-specific tests is being updated [13].

Methods and organization. The functional test is conducted in inpatient conditions of a laboratory in compliance with standard regulations and requirements to such observations. It is advisable to use a digital dynamometer, for example, the NS-Psychotest complex.

The exclusion criteria of participants before the dynamometric interval test:

1) participation in sports at a competitive level;

2) trauma (post-traumatic period), degenerative or neuromuscular skeletal disease;

3) taking medications that could affect muscle strength immediately prior to the assessment (e.g. muscle relaxants, pain killers, etc.);

4) exclusion of examination of girls during the follicular and luteal phases of the menstrual cycle.

Results and discussion. Taking into account rather unified requirements to the development of the research protocol with load testing, the development of an interval dynamometric functional test as a specific tool modelling and evaluating the degree of neuromuscular fatigue development in professional climbers is in demand.

The test consisted of performing a series of dynamometric exercises in the isometric mode with a wrist dynamometer. The test imitates cyclic load typical for climbing, where a repetitive forearm and finger muscle tension is required.

Brief study protocol. The test is conducted in inpatient conditions of a laboratory. The leading hand of the test subject is bent at the elbow joint (45°), the forearm is fixed on a horizontal platform, the palm turned upwards (fig. 1).

Fig. 1. Hand position in the test

The subject performs a series of submaximal muscle effort (squeezing the dynamometer) with preset rest intervals: 10 contractions with an effort of 75% of the maximum; the interval between efforts is 3 seconds (fig. 2, 3).

Three series are performed, with a 2-minute rest interval between them (fig. 4). The strength of each contraction, effort holding time, strength endurance, and fatigue coefficient (strength reduction by the end of the test in % of the initial level) are recorded.

This variant of an interval dynamometric test is designed to simulate muscle fatigue and assess urgent recovery of muscular endurance as a result of percussion massage of finger flexor muscles.

 

Fig. 2. Temporal characteristics of one cycle in sample series

 

Fig. 3. Temporal characteristic of a single series of sample cycles

 

Fig. 4. Temporal characteristic of three series of sample cycles

Conclusion. The proposed dynamometric interval test is a tool for assessing the functional fitness of climbers, in particular their ability to tolerate repetitive loads on finger and forearm muscles. The test results contribute to the optimization of the training process by including effective ways of urgent recovery from neuromuscular fatigue. Parallel diagnosis of the functional state of the central and autonomic nervous system, as well as a comprehensive assessment of the interrelationships of the parameters of these systems with the integral indicators of work capacity and competitive performance is advisable.

Conflict of interest. The author declares no conflict of interest.

REFERENCES

  1. Chamorro C., Armijo-Olivo S., De la Fuente C. et al. Absolute reliability and concurrent validity of hand held dynamometry and isokinetic dynamometry in the hip, knee and ankle joint: systematic review and meta-analysis. Open Medicine, 2017, vol. 12 (1), pp. 359-375. DOI: 10.1515/med-2017-0052
  2. Klawitter L.A., Hackney K.J., Christensen B.K. et al. Using Electronic Handgrip Dynamometry and Accelerometry to Examine Multiple Aspects of Handgrip Function in Master Endurance Athletes: A Pilot Study. Journal of Strength and Conditioning Research, 2023, vol. 37(9), pp. 1777-1782. DOI: 10.1519/JSC.0000000000004459
  3. Myers N.L., Farnsworth J.L., Kennedy S.M. et al. Upper Extremity Musculoskeletal Profiles in Tennis Players: A Systematic Review. Sports Health, 2024, vol. 16(6), pp. 931-937. DOI: 10.1177/19417381231223540
  4. Keating J.L., Matyas T.A. The Influence of Subject and Test Design on Dynamometric Measurements of Extremity Muscles. Physical Therapy, 1996, vol. 76 (8), pp. 866–889. DOI: 10.1093/ptj/76.8.866a
  5. Jeon S., Miller W.M., Kang M. et al. The Minimum Number of Attempts for a Reliable Isometric Strength Test Score. Journal of Science in Sport and Exercise, 2020, vol. 2, pp. 89-95. DOI: 10.1007/s42978-019-00035-3
  6. Oliveira H.B., da Silva Marques V.A., Fernandes L.F.R.M. Analysis of the force–time curve and median frequency of surface electromyographic signals during isometric hand grip test for estimation of a temporal pattern for muscle strengthening. Research on Biomedical Engineering, 2023, vol. 39, pp. 179-187. DOI: 10.1007/s42600-023-00262-2
  7. Mendez-Rebolledo G., Ruiz-Gutierrez A., Salas-Villar S. et al. Isometric strength of upper limb muscles in youth using hand-held and hand-grip dynamometry. Journal of Exercise Rehabilitation, 2022, vol. 18(3), pp. 203-213. DOI: 10.12965/jer.2244198.099
  8. Cataldi D., Bennett J.P., Wong M.C. et al. Accuracy and precision of multiple body composition methods and associations with muscle strength in athletes of varying hydration: The Da Kine Study. Clinical Nutrition, 2024, vol. 43(1), pp. 284-294. DOI: 10.1016/j.clnu.2023.11.040
  9. Pournasiri F., Zarei M., Mainer-Pardos E., Nobari H. Isometric and isokinetic strength of lower-limb muscles in female athletes during different phases of menstrual cycle: a causal-comparative study. BMC Womens Health, 2023, vol. 23(1), art. ID 657. DOI: 10.1186/s12905-023-02819-w
  10. Wilson G.J., Murphy A.J. The Use of Isometric Tests of Muscular Function in Athletic Assessment. Sports Medicine, 1996, vol. 22, pp. 19-37. DOI: 10.2165/00007256-199622010-00003
  11. Quaine F., Vigouroux L., Martin L. Finger flexors fatigue in trained rock climbers and untrained sedentary subjects. International Journal of Sports Medicine, 2003, vol. 24(6), pp. 424-427. DOI: 10.1055/s-2003-41174
  12. MacLeod D., Sutherland D.L., Buntin L. et al. Physiological determinants of climbing-specific finger endurance and sport rock climbing performance. Journal of Sports Sciences, 2007, vol. 25(12), pp. 1433-1443. DOI: 10.1080/02640410600944550
  13. Stien N., Saeterbakken A.H., Andersen V. Tests and Procedures for Measuring Endurance, Strength, and Power in Climbing-A Mini-Review. Frontiers in Sports and Active Living, 2022, vol. 4, Art. ID 847447. DOI: 10.3389/fspor.2022.847447

INFORMATION ABOUT THE AUTHORS:
Mikhail V. Gromyko – Post-graduate Student, Institute of Sports, Tourism and Service, South Ural State University (National Research University), Chelyabinsk, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Pavel A. Bajguzhin – Leading Researcher, Sports Science Research Center, South Ural State University (National Research University), Chelyabinsk, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.. 

For citation: Gromyko M.V., Bajguzhin P.A. Development of an interval dynamometric functional test. Russian Journal of Sports Science: Medicine, Physiology, Training, 2025, vol. 4, no. 2(14). DOI: 10.24412/2782-6570-2025_04_02_1

Search