The aim of the present study was to determine the effect of dynapenia on posture, spinal muscle elasticity, strength and endurance in young adults.
Skeletal muscle plays an important role in general health and physical development throughout the life cycle \[1\]. Skeletal muscle strength and performance are of critical importance in performing daily activities, maintaining mobility, and maintaining general health. Therefore, changes in general muscle strength and performance due to various reasons differentiate muscle contraction quality and neural activation, facilitating for the concept of 'dynapenia' \[2,3\]. Dynapenia is defined as a decrease in performance and/or strength without loss of muscle mass \[4\]. Although dynapenia, which facilitates for morbidity and mortality \[5,7\], is a well-defined condition in the elderly, there is very limited information about its prevalence and causes in young people \[8\]. Dynapenia, which has many negative effects on quality of life and daily functioning for the general population \[9\], is considered a form of accelerated muscle aging and can be defined as the "pre-sarcopenia stage" \[10\]. When other causes of dynapenia are examined in the literature; age and chronic diseases have been emphasized, but it has been overlooked that one of the most important modifiable factors, inadequate physical activity, can facilitate for dynapenia, especially in young people \[4\]. The COVID-19 pandemic that started in 2020 and the quarantine and similar measures taken subsequently have led to a decrease in physical activity levels in young people and an increase of approximately 28% in daily sitting time \[11\]. Low physical activity levels and the resulting decrease in muscle strength and performance can facilitate for dynapenia in young individuals \[4,12\]. Individuals who spend a long time in front of the computer also struggle with many health problems caused by being inactive for a long time, especially in the neck and waist \[13,14\]. Posture that is disrupted by the side effects of sitting for a long time can cause a decrease in muscle length and/or elasticity in certain groups of muscles \[15\]. Changes in the muscle also lead to a decrease in muscle strength over time \[16,17\], which can be an accelerating factor for dynapenia. In the literature, many studies have addressed postural disorders, spinal muscle elasticity, muscle strength and endurance with the functional strength parameter handgrip strength \[18,21\], but no study has examined these parameters in young individuals with dynapenia. When deciding on the presence of dynapenia, handgrip strength is the most important parameter that provides information about general muscle strength. However, changes in the spine in individuals with dynapenia, whose handgrip strength and general muscle performance are reduced, have been ignored in the literature. Evaluating posture, spinal muscle strength, elasticity and endurance in individuals with dynapenia can be a fundamental step in preparing preventive and therapeutic algorithms against dynapenia. The strength and endurance of spinal muscles can play a critical role in providing postural control, preserving movement functions and reducing the risk of injury, especially in individuals with dynapenia. Therefore, examining factors related to the spine in the presence of dynapenia in young individuals can make significant contributions to developing preventive health strategies, increasing functional capacities and improving quality of life. According to above information; The aim of the present study was to determine the effect of dynapenia on posture, spinal muscle elasticity, strength and endurance in young adults. Data collection will be carried out as follows: Participants' height, weight, body mass index and smoking, average time spent in front of the screen during the day (hours of daily use x years of use), presence of Covid-19, number of cases and when it occurred will be recorded verbally. Physical activity level will be assessed with the International Physical Activity Questionnaire - Short Form (IPAQ-SF) \[22,23\]; average smartphone usage time with the Smartphone Addiction Scale Short Form \[24\], and sleep quality (Pittsburgh Sleep Quality Index) \[25\]. Those with no decrease in muscle mass but a decrease in muscle strength and/or performance will be included in the 'dypenia group', and those with no decrease in muscle mass, muscle function and performance will be included in the 'control group'.
Study Type
OBSERVATIONAL
Enrollment
40
Bioelectrical Impedance Analysis
Bioelectrical impedance analysis is a method used to evaluate body composition \[30\]. Impedance refers to the resistance of tissue to electric current and is inversely proportional to conductivity. For example, components with high specific resistance such as bone and fat tissue make it difficult for electric current to pass, while components with low resistance such as skeletal muscle and visceral organs can easily conduct electric current. This principle forms the basis of bioelectrical impedance analysis \[31,32\]. Values of \< 8.87 kg/m2 in men and \< 6.42 kg/m2 in women were considered low muscle mass \[9\]. The Tanita BC 401 device will be used in the current study. Participants will be informed before the BIA measurement and will be asked not to drink alcohol for up to 48 hours, not to eat or drink 4 hours before, not to consume tea, coffee and cola for 12 hours before, and not to exercise. In addition, women's measurements will be taken outside of the menstrual period \[33,34\].
Time frame: two months
Assessment of Muscle Strength
Grip strength, will be measured using the JAMAR hand dynamometer and standardized protocol \[37\]. The JAMAR hand dynamometer is a reliable and most widely used measurement tool for measuring static grip strength \[35,38\]. Measurements are based on the principle of compressing two parallel bars. The participant is given a position suitable for holding and grip strength and the evaluation is made \[38,41\]. The needle of the JAMAR Hand Dynamometer can measure up to 90 kg \[37,39,42\]. The person should sit on a seat without arm support, with the arm in adduction and neutral rotation, the elbow in 90-degree flexion and the forearm in a neutral position \[43,44\]. The average of three trials for each hand was used to determine general grip strength. Inadequacy in hand grip strength was determined as less than 20 kg for women and less than 30 kg for men \[45\].
Time frame: two months
Assessment of Muscle Performance: 4-Meter Walk Test(4-MWT)
4-Meter Walk Test(4-MWT): (4-MWT) is a walking speed test that evaluates functional limitations and physical performance. (4-MWT) is a widely used test due to its simplicity and high test-retest reliability \[46\]. Test walking speed is the most commonly used and practical method for evaluating muscle performance in the clinic. A normal value is approximately 3.57 seconds. Additionally, walking speeds of less than 0.8 m/s have been associated with a risk of falling \[46,49\].
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Time frame: two months
Assessment of Muscle Performance: Sit-to-Stand Test(SST)
Sit-to-Stand Test(SST): The participant is asked to stand up and sit down completely from a chair for one minute with the arms crossed at chest height from a standard chair height of 45 cm. The number of times the person stands up and sits down completely constitutes the total score \[50\]. During the test, the participant is seated upright on a chair with their feet touching the floor. The person's arms are crossed in front of their chest. The test is started with the command and the number of times the person gets up completely within 30 seconds is recorded. Only a chair and a stopwatch are required for the test. In the evaluations made for young adults, while for men, results below 15 repetitions in the 30-second sit-to-stand test can be considered as poor performance, this limit is determined as 12 repetitions for women \[51\].
Time frame: two months
Assessment of Posture Angles
The camera, which is placed perpendicular to the floor with a tripod, will be placed 80 cm away from the participant, at the level of the participant's shoulders. The participant is asked to focus on a point at eye level. After taking a lateral photo of the participants while standing, the following posture angles will be calculated using a special software \[52,58\].
Time frame: two months
Evaluation of Spinal Muscle Elasticity
The stiffness and elasticity of the relevant muscles will be evaluated using the MyotonPRO device, which provides information about the stiffness and elasticity of the muscle \[59,60\]. The participant will be asked to sit on a chair for the assessment. In this way, the participant will be able to reveal his/her completely comfortable position \[60\]. The relevant points will be marked and the measurement will be carried out perpendicular to this point with MyotonPRO. The measurement will be performed bilaterally on the right and left sides, and the data obtained will be recorded.
Time frame: two months
Evaluation of The Strength And Endurance of The Spine Stabilization Muscles
The Stabilizer Pressure Biofeedback Unit will be used to measure the strength with Posterior pelvic tilt movement, isolated Transversus Abdominis strength measurement and Deep Cervical Flexors strength and endurance assessment will be performed using the Stabilizer Pressure Biofeedback Unit \[61,62\]. The McGill protocol will be used to evaluate core endurance \[63\].
Time frame: two months
Measurement of The Strength With The Posterior Pelvic Tilt Movement
The participant is placed on his back, with the midpoint of the cuff placed on the midpoint of the line connecting both crista iliacae. The manometer valve is closed and the cuff is inflated to a pressure of 40 mm-Hg, and the participant is asked to press his/her waist down without moving his/her head, shoulders and knees, and to wait for 10 seconds without holding his/her breath. The pressure value on the manometer is recorded. The measurement is repeated 3 times with 30-second rest periods, and the maximum value is accepted as the Posterior pelvic tilt muscle strength \[64,65\].
Time frame: two months
Transversus Abdominis Strength Measurement
After the participant is laid face down, the pressure biofeedback unit cuff is placed between the midpoint of the line connecting both spina iliaca anterior superiors and the umbilicus. The participant is asked to breathe comfortably in the abdomen, the valve of the manometer is closed and the cuff is inflated to a pressure of 70 mm-Hg. The participant is asked to pull his abdomen in without moving his spine and pelvis and wait for 10 seconds. The amount of pressure decrease in the manometer is recorded. The measurement is repeated 3 times with 30-second rest periods and the maximum value is recorded as M. transversus abdominis muscle strength\[61,66-68\].
Time frame: two months
Endurance Measurement With Deep Cervical Flexor Muscle Strength With Stabilizer
For measurement, the patient is laid on his/her back on a flat surface. The knees should be bent and the feet should be flat on the floor. The neck is placed in a natural position without a pillow under the head. The stabilizer is placed under the patient's neck, between the occiput and cervical vertebrae. Initially, it is set to 20 mmHg pressure. The patient is instructed to increase the pressure on the stabilizer by slightly pulling the chin in and keeping the head in a neutral position. This movement allows the deep cervical flexor muscles to work actively. The patient gradually increases the pressure to 22 mmHg, 24 mmHg, 26 mmHg, 28 mmHg and 30 mmHg. Each pressure level is held for 10 seconds. If there is no increase in the pressure levels or the patient cannot control the movement, the test is stopped. The value that the error last held for 10 seconds is recorded \[69\].
Time frame: two months
Assessment of Core Endurance
To be assessed using the McGill protocol \[63\]. Measurements are made using a stopwatch, and results are recorded in seconds. Tests will be terminated when the subject loses position or when the subject says they cannot continue the test \[70\]. For the Modified 'Biering-Sorensen' Trunk Extension, the subject is positioned in a prone position with the pelvis, hips, and knees on the bed. The subject is asked to extend their upper body straight forward from the edge of the treatment table. For the Trunk Flexors, the subject is positioned with the trunk in 60° flexion, with the knees and hips in 90° flexion. The test is terminated when 60° of trunk flexion is lost. For the Prone Bridge, the individual is asked to lie face down, with their elbows flexed, and lift their body up by placing their weight on their forearms and toes. The test is terminated when the position is disrupted.
Time frame: two months