Discussion
The study found that individuals who performed the Salaah presented with reasonably healthy morphology and cardiovascular values regarding BMI, BF%, RHR, resting SBP, resting DBP, MMT and MVC average values. A secondary finding of this study suggested that performing a timed simulation of four raka’ah movements of the Salaah lowered DBP. Additional findings of this study demonstrated electromyographic activity values of the VMO muscle through the Salaah for two movement transitions of the prayer. The MMT strength values for the quadriceps femoris and gastrocnemius muscles were presented and had positive relationships with the MVC average output data.
Selected morphological data
For morphological findings, sedentary individuals who perform the daily Salaah had an average BMI of 22.02 kg/m2 (±3.24), which implied that they were within the healthy ranges and classified as low risk. In general, BMI is more accurately demonstrated as a risk profile indicator than a performance indicator.9 The American College of Sports Medicine has documented the clinically recognised norms for a healthy BMI between 18.5 kg/m2 and 24.9 kg/m2. The finding of this study complements previous research where rhythmic light aerobic activity participation had a positive effect on maintaining a healthy BMI.10 This study found the sedentary participants’ BF% (9.06%±2.26) below the average norms for BF%. This finding, however, could still be attributed to lifestyle choices and calorie intake, which was not a finding of this study.
African ethnicity of participants may have also played a role in the BF% for these participants. Future studies should further investigate the relationship between BF% and diet for those who perform daily Salaah. These findings may apply to African ethnicity and specific physiology. Another finding of this study showed that in terms of phenotypes, participants were found to have lower BMI and BF%. Further investigation using a larger sample with a more robust methodology is required to illicit the clinical benefits of Salaah among African populations for these health parameters.
For skinfold data, the calf (8.30 mm±3.42 mm) and thigh (10.40 mm±4.55 mm) skinfolds demonstrated lower average values for sedentary individuals. Participants had a notable lack of physical conditioning. According to Oliveira et al,11 the findings of this study were almost similar to those of athletes and those who condition those muscle groups. A trend is possible, suggesting that participants passively conditioned their calf and thigh musculature through daily Salaah. The Salaah engages musculoskeletal functions of the lower extremity through various movements of the Salaah.12 Cheung et al13 suggested that calf and thigh musculature have the potential to become conditioned through Yoga and Tai-chi, which are similar aerobically to Salaah.13 Future study interventions investigating passive conditioning of musculature and skinfold thickness through the Salaah as a clinical experimental tool are warranted.
Selected cardiovascular data
The average RHR for this sample (78.50±10.70) was within acceptable healthy range values. Cardiovascular health studies have established that lower RHR indicates improved cardiovascular functioning. For example, Van CAG et al studied the clinically recognised norm for adults’ RHR to be 60 bpm to 100 bpm.14 The average for RHR 78.59 bpm, indicating a mildly higher resting value for those who are conditioned who average at 60 bpm. Compared with sedentary individuals, the sample had scored lower than 80 bpm. When evaluating this difference, the sample was healthier than sedentary but not as fit as conditioned norms. Performing the daily Salaah could contribute to this finding.
The average resting SBP (124 mm Hg±6.71 mm Hg) and resting DBP (81.90 mm Hg±7.64 mm Hg) converged with the universal norm of 120/80 mm Hg.15 The resting DPB for participants was within a healthy range.16 Motoyama et al17 and Port et al18 link high DBP (>40 years) to increased risk of heart disease.19 The study suggests Salaah maintains healthy resting BP despite no conditioning. Ghous and Malik20 pointed out the aerobic nature of Salaah when compared with other low-intensity cardiovascular activities and had an improved effect on resting BP when performed daily Salaah.12
Simulating a four-rakaat Salaah showed minimal change in BP compared with resting levels. When comparing resting DBP, there was evidence of decreased post-Salaah DBP (78.30 mm Hg±7.38 mm Hg) after the four rakaat timed activity. Decreases in DBP are present after low-intensity aerobic activity participation and place individuals at lower risk for CVD.19 A study by Otsuki, Kotato & Zempo-Miyaki21 substantiated the findings of this research for resting SBP and post-Salaah SPB, which are similar to each other after performing the timed Salaah activity.22 It is suggested that this finding could be attributed to the regular participation of Salaah, whereby SPB is regulated throughout the activity in terms of CVD risk profile.
Selected neuromuscular data
During the neuromuscular investigation, selected measurements were taken through EMG and manual muscle testing. To establish baseline measurements, the surface EMG of the VMO muscle was tested on the participants’ dominant leg. The resulting MVC average values (25.33 μV±9.20 μV) obtained from these measurements were shown to be in line with the norms for regular surface EMG action potentials of asymptomatic individuals, which generally range from less than 50 μV up to 20 μV. However, Mathur, Eng & MacIntyre23 recommend that these action potentials and output values may differ depending on the specific muscle group being tested through EMG.24 The sample showed normal resting MVC and VMO activation. Since the VMO muscle acts as one of the knee extensors during Salaah movement transitions, it is evident that the sample was within the reasonably healthy condition for VMO activation. A study by Abdul Malik et al25 suggests that regular Salaah could be a knee-saver for those who sit considerably, especially if they have optimal muscle activation.26 Further investigations into the activity of the VMO and the Salaah are recommended.
EMG activity of the VMO muscle through two movement transitions of the Salaah was investigated. During the first transition, the participant was requested to move from the Qiyaam position into the Sujood position, demonstrating the QS average (21.21 μV±10.27 μV). The second transition, the TQ average value (24.47 μV±13.17 μV), measured the EMG of the VMO muscle between kneeling in the Tahiyaat and back into the upright standing Qiyaam position.
As a novel finding, the study tracked muscle activity in the VMO during specific Salaah movements to see how this key muscle works. The results demonstrated sufficient muscle activation within the VMO muscle during this transition. This encourages VMO engagement in the Salaah activity. When repeated over four raka’ah or sequences, it can be suggested that the VMO muscle is passively conditioning during the transitions, which are repeated through various rakaats. Regular passive conditioning of the VMO muscle has positive outcomes in treating and preventing patellofemoral pathologies and injury occurrence.27 Notably, the TQ transition movement is similar to the functional sit-to-stand, which requires lower body strength. Many muscle groups are recruited during transitions of the Salaah.28 Future studies should prioritise EMG analysis for long-term neuromuscular effects and explore knee health and cardiovascular benefits compared with non-Salaah participants.
The study further tested isometric MMT using a handheld dynamometer through the prescribed method.6 The results for the right (33.34 Nm/kg±7.41 Nm/kg) and left (29.51 Nm/kg±7.16 Nm/kg) quadriceps femoris muscle groups demonstrated the participants’ isometric muscle strength. Kittelson et al29 found similar results for isometric muscle strength for sedentary individuals similar to conditioned ones.30 In relation to this, it is suggested that participating in Salaah movements may positively impact the muscle strength of the knee extensors. Skou et al31have also recommended that repetitive knee extensor movements play a role in minimising the risk of developing knee pathologies.32
In addition, isometric MMT measurements of the right (28.80 Nm/kg±9.94 Nm/kg) and left (28.83 Nm/kg±8.96 Nm/kg) gastrocnemius muscles were conducted. The gastrocnemius is known anatomically as a powerful plantarflexor at the ankle joint and acts within daily locomotive activities. It is imperative to note that the strength of this muscle and its associated range of motion wanes as the human lifespan progresses.33 Similar to the quadriceps, it can be postulated that gastrocnemius muscles are conditioned by daily Salaah movements, especially the TQ transition.
Correlations
Selected correlations between variables of this study were investigated due to their relationship with optimal morphological, cardiovascular and neuromuscular health.
Skinfolds and MMT testing
Calf skinfolds correlated positively with calf and thigh MMT values, but no significant link emerged between MMT and skinfolds. Lafère et al34 recommend a larger sample size to strengthen statistical significance in skinfold-muscle strength relationships.35
RHR and maximum voluntary contraction
Although not statistically significant, a negative, weak correlation was found between RHR and the EMG average MVC (r=−0.03; p=0.91) for the VMO. Due to the negative relationship, as RHR increased, the MVC output average of electrical potential diminished. A larger sample to investigate the relationship would be warranted.36 Through this association, lower RHRs linked to Salaah might improve muscle function in everyday activities.37 It is also important to note that the regulation of RHR aids in performing isometric neuromuscular activities.38
Selected cardiovascular data and MVC average
The study found RHR negatively correlated (r=−0.03; p=0.91) with the MVC average. Due to the weak nature of this relationship, the study cannot generalise the possibility that lower RHRs may be beneficial to MVC output measurements. On further inquiry, the study found negative correlations between post-Salaah SBP and MVC average (r=−0.19; p=0.42) and between the post-Salaah DBP and the MVC average (r=−0.40; p=0.08), which were not found to be statistically significant. This study suggests higher BP weakens the VMO muscle MVC output. However, larger studies on Salaah are required to confirm this link.
MVC average and quadricep femoris MMT testing
Weak, positive correlations were found between the MVC average and the right quadriceps femoris MMT (r=0.14; p=0.56) and the left femoris quadriceps MMT (r=0.18; p=0.44). Since these findings were not statistically significant, no significant change in MVC output was found in this sample. Larger studies with more statistical power are required to discover if Salaah improves muscle strength.39
BMI and selected cardiovascular variables
Several correlations between BMI and selected cardiovascular variables of the study were explored. Non-significant, positive correlations were found between BMI and RHR (r=0.26; p=0.27), BMI with resting SBP (r=0.49; p=0.03) and resting DBP (r=0.40; p=0.08). BMI was positively correlated with post-Salaah SBP (r=0.27; p=0.26) and post-Salaah DBP (r=0.36; p=0.12). These findings suggested that as BMI increased, a proportionally positive increase could be expected in RHR and resting BP values. In essence, and according to previous clinical literature, high BMI values increase CVD risk.40 Shigetoh et al41 support this finding in their study, which explored the risks of elevated BMI and its relationship with RHR and resting BP. However, the findings of this research study are that the risk profile is dependent.42 The participants had demonstrated acceptable BMI values despite being sedentary. The positive correlation (r=0.69; p=0.00) between the BMI and BF% was statistically significant, confirming that increases in BF% are directly proportional to an increased risk profile and BMI. Regular Salaah as a low-impact exercise might improve BMI, potentially lowering CVD risk with further scrutiny.
Limitations
This study includes several limitations. First, the study used convenience sampling due to participants’ willingness in the recruitment region. Although successful in gathering and evaluating clinical data on a unique population, some findings may be prone to selective bias. As such, the study may only suggest and indicate trends in the discussion section. To alleviate the selective bias aspect, the study is still valuable in establishing the groundwork for future studies to investigate the Salaah and its associated physiology through a control group who do not perform the Salaah. If larger samples are not available, then a study methodology that is robust, reliable and replicable may be required for smaller samples with a control group. The addition of clinical intervention tools, study control groups and qualitative data may add merit to the statistical findings that require adequate significance for generalisation to larger populations. Based on the interpretation of results, future research using a control group may aid in confirming whether the Salaah has beneficial effects on the health of sedentary individuals.
The second limitation of this study was that it used participants of African ethnicity from South Africa. Regarding phenotypes and physiology, one should be aware of the clinical limitations of investigating a sample of only one racial ethnicity. Although valuable in its findings and groundwork, this research study has not delivered data on other ethnic groups in South Africa. This aspect must be investigated in future studies where a combination of various ethnicities should be included in a random sample. This will aid in producing a greater replication of the methodology used in this study for future studies on the Salaah and sedentary populations.
Recommendations
Future physiological studies may be required to investigate the parameters explored in this study by providing findings with greater statistical power. Since most findings in this study hold merit but were inconclusive due to the limitations of COVID-19 during data collection, it is recommended that larger samples be used to establish more rigorous methodologies when studying the Salaah. Although using a small sample of participants (n=20) and a statistical power of 80%, the study could still detect changes in DBP from performing the Salaah. Based on the unpredictability of conducting experimental research, it is clear that when samples are specific and unique, a clinical intervention approach to the Salaah may be explored with added control groups when investigating populations who perform the Salaah either as an act of worship and/or as physical activity. It may also be worthwhile to explore other outputs of the electrical activity of the human body, such as electroencephalography and potentially combine mixed methods studies with added qualitative data presented on the Salaah, especially in the South African context, where research on the Salaah is limited. Future studies may also pursue research into comparing individuals who perform Salaah with individuals who do not perform. Investigating the relationship between flexibility along muscle strength and Salaah may be of further interest for prospective research.