A comparison of muscle activity and heart rate response during backward and forward walking on an underwater treadmill

The Application of Surface Electromyography Technology in Evaluating Paraspinal Muscle Function

Surface electromyography (sEMG) has emerged as a valuable tool for assessing muscle activity in various clinical and research settings. This review focuses on the application of sEMG specifically in the context of paraspinal muscles. The paraspinal muscles play a critical role in providing stability and facilitating movement of the spine. Dysfunctions or alterations in paraspinal muscle activity can lead to various musculoskeletal disorders and spinal pathologies. Therefore, understanding and quantifying paraspinal muscle activity is crucial for accurate diagnosis, treatment planning, and monitoring therapeutic interventions. This review discusses the clinical applications of sEMG in paraspinal muscles, including the assessment of low back pain, spinal disorders, and rehabilitation interventions. It explores how sEMG can aid in diagnosing the potential causes of low back pain and monitoring the effectiveness of physical therapy, spinal manipulative therapy, and exercise protocols. It also discusses emerging technologies and advancements in sEMG techniques that aim to enhance the accuracy and reliability of paraspinal muscle assessment. In summary, the application of sEMG in paraspinal muscles provides valuable insights into muscle function, dysfunction, and therapeutic interventions. By examining the literature on sEMG in paraspinal muscles, this review offers a comprehensive understanding of the current state of research, identifies knowledge gaps, and suggests future directions for optimizing the use of sEMG in assessing paraspinal muscle activity.

A Systematic Review of Gait Analysis in the Context of Multimodal Sensing Fusion and AI

BACKGROUND

Neurological diseases are a leading cause of disability and mortality. Gait, or human walking, is a significant predictor of quality of life, morbidity, and mortality. Gait patterns and other kinematic, kinetic, and balance gait features are accurate and powerful diagnostic and prognostic tools.

OBJECTIVE

This review article focuses on the applicability of gait analysis using fusion techniques and artificial intelligence (AI) models. The aim is to examine the significance of mixing several types of wearable and non-wearable sensor data and the impact of this combination on the performance of AI models.

METHOD

In this systematic review, 66 studies using more than two modalities to record and analyze gait were identified. 40 studies incorporated multiple gait analysis modalities without the use of artificial intelligence to extract gait features such as kinematic, kinetic, margin of stability, temporal, and spatial gait parameters, as well as cerebral activity. Similarly, 26 studies analyzed gait data using multimodal fusion sensors and AI algorithms.

RESULTS

The research summarized here demonstrates that the quality of gait analysis and the effectiveness of AI models can both benefit from the integration of data from many sensors. Meanwhile, the utilization of EMG signals in fusion data is especially advantageous.

CONCLUSION

The findings of this review suggest that a smart, portable, wearable-based gait and balance assessment system can be developed using multimodal sensing of the most cutting-edge, clinically relevant tools and technology available. The information presented in this article may serve as a vital springboard for such development.

Comparison of forward versus backward walking on spatiotemporal and kinematic parameters on sand: A preliminary study

The purpose of this study was to investigate the spatiotemporal and kinematic parameters of backward walking (BW) and forward walking (FW) on sand. Randomly selected subjects (n = 28) were categorized into a sand group (SG, n = 14) and an overground group (OG, n = 14). SG was directed to perform both FW and BW on sand, while OG performed the same on the overground. Spatiotemporal and kinematic parameters were measured using the LegSys + device. The comparative findings of both the groups showed that the spatiotemporal parameters of SG varied significantly from those of OG in both FW and BW conditions (p < 0.05). The kinematic parameters varied significantly between the two groups only in the FW condition (p < 0.05). When compared within each group, spatiotemporal and kinematic parameters in the BW condition were significantly different from those in the FW condition. However, the percentages of stance, swing, and double support were not significantly different between FW and BW conditions (p > 0.05). This study suggests that sand walking is associated with a different gait pattern than overground walking, as evident from the analysis of the results of spatiotemporal and kinematic parameters in both FW and BW conditions. Therefore, sand walking can be used as a new approach to gait and balance training in clinical practice.

Comparing Acceleration and Change of Direction Ability Between Backpedal and Cross-over Run Techniques for Use in American Football

ABSTRACT

Angelino, D, McCabe, TJG, and Earp, JE. Comparing acceleration and change of direction ability between backpedal and cross-over run techniques for use in American football. J Strength Cond Res 35(1): 47-55, 2021-In American football, defensive backs guard receivers using either cross-over (CO) run or backpedal (BP) techniques, but the efficacy of these techniques is unknown. The purpose of this study was to compare linear acceleration (LA) and change of direction (CoD) ability when using CO and BP. Collegiate football defensive backs participated in LA (n = 13) and CoD (n = 7) testing. During LA, subjects performed CO, BP, and forward sprints with split times taken between 0-3 and 3-5 yd and ground reaction forces recorded 0 and 3 yd from the start. During CoD testing, subjects performed the CO or BP for 3 yd and then were given a cue to sprint to a gate 5 yd away in 1 of 4 directions (downfield, midfield, sideline, or upfield). In LA, CO was faster than BP between 0-3 yd (Δ -0.20 ± 0.02 seconds, p = 0.000) and 3-5 yd (Δ -0.12 ± 0.02 seconds, p = 0.000). At the start of the movement, CO demonstrated greater propulsive forces (p = 0.017). However, 3 yd from the start, CO demonstrated greater propulsive forces and reduced braking forces (p = 0.000 & 0.003). In CoD, CO was faster than BP when running in the downfield (Δ 0.21 ± 0.05 seconds, p = 0.044) and lateral directions (Δ 0.21 ± 0.08 seconds, p = 0.035), but similar in the upfield direction (Δ 0.01 ± 0.08, p = 0.986). Our results indicate that CO is superior to BP in LA, CoD ability, and movement efficiency and support the use of CO for defensive backs.

Comparing the Effects of Different Types of Aquatic Walking on Endurance and Electrical Activities of Spine Extensor Muscles in Men with Nonspecific Chronic Back Pain

Background

Chronic back pain is one of the most challenging medical problems worldwide that results in disability, physical problems, and high costs for the family and society. Therefore, it can be very beneficial to find an appropriate treatment with minimum side-effects for this disease. The present study attempted to compare the effects of different water gait protocols on the endurance and electrical activity of spine extensor muscles in men with nonspecific chronic back pain.

Methods

The study adopted an experimental design in which 30 men with non-specific chronic back pain were selected through convenience sampling and using simple randomization method assigned into three groups of forward walking, backward walking, and sideways walking. Walking exercises were performed for 8 weeks, three sessions per week for 30 min. Twenty-four hours before and 48 h after the intervention, the endurance of spine extensor muscles and electrical activities were measured using the Ito test and electromyography, respectively. Data were analyzed in SPSS 23 using paired sample t-test and analysis of variance.

Results

The results showed that backward walking in water significantly increases endurance and electromyography activities of spine extensor muscles (P < 0.05), while forward and sideways walking had no significant effect on these variables (P > 0.05). The results obtained from Bonferroni post-hoc test showed a significant difference between the strength of trunk extensor muscles and EMG of spinal cord extensor muscles in forward and backward water gait groups (P = 0.001, 0.006).

Conclusions

According to the findings of this study, it seems that walking backward can be an effective therapeutic method for patients with chronic back pain.

Effect of Underwater Treadmill Gait Training With Water-Jet Resistance on Balance and Gait Ability in Patients With Chronic Stroke: A Randomized Controlled Pilot Trial

Objective: The purpose of this study was to determine the effects of underwater treadmill gait training with water-jet resistance and underwater treadmill gait training with ankle weights on balance and gait abilities in chronic stroke patients.

Methods: Twenty-two inpatients and outpatients with stroke-induced impairments were randomly assigned into two groups: an underwater treadmill gait training with water-jet resistance group (n = 11) and an underwater treadmill gait training with ankle weights group (n = 11). Participants received conventional physical therapy for 30 min and underwater treadmill gait training with water-jet resistance or ankle weights for 30 min. Intervention was performed 5 days a week for 4 weeks. The Balance System SD was used to assess static and dynamic balance. The GAITRite system was used to assess gait velocity, cadence, step length, stride length, and swing phase. All measurements were performed at the beginning of the study and 4 weeks after the intervention.

Results: The water-jet resistance group and ankle weights group showed significant improvement in static balance (P < 0.00 vs. P = 0.01), dynamic balance (P < 0.00 vs. P = 0.57), gait velocity (P < 0.00 vs. P = 0.037), cadence (P < 0.00 vs. P = 0.001), step length (P < 0.00 vs. P = 0.003), stride length (P < 0.00 vs. P = 0.023), and swing phase (P < 0.00 vs. P < 0.00). However, the static and dynamic balance ability score (P < 0.00), gait velocity (P < 0.00), cadence (P < 0.00), step length (P < 0.00), stride length (P < 0.00), and swing phase (P = 0.023) in the group that received underwater treadmill gait training with water-jet resistance improved more than in the group that received underwater treadmill gait training with ankle weights.

Conclusions: Our results demonstrated that underwater treadmill gait training with water-jet resistance is effective in improving static and dynamic balance as well as gait abilities in chronic stroke patients. Thus, training using underwater treadmill gait training with water-jet resistance may be useful in facilitating active rehabilitation in chronic stroke patients.

Monitoring of Heart Rate from Photoplethysmographic Signals Using a Samsung Galaxy Note8 in Underwater Environments

Photoplethysmography (PPG) is a commonly used in determining heart rate and oxygen saturation (SpO₂). However, PPG measurements and its accuracy are heavily affected by the measurement procedure and environmental factors such as light, temperature, and medium. In this paper, we analyzed the effects of different mediums (water vs. air) and temperature on the PPG signal quality and heart rate estimation. To evaluate the accuracy, we compared our measurement output with a gold-standard PPG device (NeXus-10 MKII). The experimental results show that the average PPG signal amplitude values of the underwater environment decreased considerably (22% decrease) compared to PPG signals of dry environments, and the heart rate measurement deviated 7% (5 beats per minute on average. The experimental results also show that the signal to noise ratio (SNR) and signal amplitude decrease as temperature decreases. Paired t-test which compares amplitude and heart rate values between the underwater and dry environments was performed and the test results show statistically significant differences for both amplitude and heart rate values (p < 0.05). Moreover, experimental results indicate that decreasing the temperature from 45 °C to 5 °C or changing the medium from air to water decreases PPG signal quality, (e.g., PPG signal amplitude decreases from 0.560 to 0.112). The heart rate is estimated within 5.06 bpm deviation at 18 °C in underwater environment, while estimation accuracy decreases as temperature goes down.

Backward walking alters vastus medialis oblique/vastus lateralis muscle activity ratio in females with patellofemoral pain syndrome

Objectives

This study aims to examine the effect of backward walking (BW) and forward walking (FW) on the myoelectric activity ratio of the vastus medialis oblique (VMO)/vastus lateralis (VL) in females with patellofemoral pain syndrome (PFPS).

Patients and methods

Between September 2016 and December 2016, a total of 40 female participants (mean age 20.9±1.9 years; range, 19 to 26 years) were included in the study. The participants were divided into two groups as those with unilateral PFPS (PFPS group, n=20) and healthy controls (Control group, n=20). Surface electromyography (EMG) from VMO and VL muscles were collected during FW and BW at a speed of 3 km/h using the Myomonitor® IV EMG system.

Results

There was a significant increase in the EMG activities of the VMO and VL muscles during BW compared to FW in PFPS and healthy groups (p=0.001). During BW, the VMO activity of PFPS was significantly higher than the healthy controls (p=0.013) without any significant difference in the VL activity (p=0.916). During FW, there was no significant difference in the VMO and VL activities between the groups (p=0.348 and p=0.705), respectively. The VMO/VL ratio of the PFPS group during BW was significantly higher than the FW ratio (p=0.001) without any significant difference between BW and FW of the healthy group (p=0.841). During BW, the ratio of the PFPS group was significantly higher than compared to the healthy controls (p=0.016) without any significant difference between the groups during FW (p=0.100).

Conclusion

Our study results show that BW increases the VMO muscle activation and preserve the ideal VMO/VL ratio in PFPS patients. Therefore, clinicians should consider BW training when developing rehabilitation programs for females with PFPS.

Backward walking effects on activation pattern of leg muscles in young females with patellofemoral pain syndrome

Background/Aims:

Little is known regarding the activation of knee and hip muscles during backward walking in patellofemoral pain syndrome. This study examineD the effects of backward walking and forward walking on the activation of knee extensors, hip abductors, and adductors in patients with patellofemoral pain syndrome.

Methods:

A total of 20 females with patellofemoral pain syndrome and 20 age-matched typically healthy female controls participated in this study. Surface electromyography from vastus medialis obliquus, vastus lateralis, gluteus medius, and adductor longus muscles were collected during forward walking and backward walking.

Findings:

The patellofemoral pain syndrome group had a significantly higher normalised root mean square of the vastus medialis obliquus, vastus lateralis and gluteus medius muscles (P=0.001), without significant difference in adductor longus muscle activity during backward walking versus forward walking (P=0.098). During forward walking, the patellofemoral pain syndrome group showed significantly higher activation of adductor longus muscle (P=0.001) and significantly lower activation of the gluteus medius muscle (P=0.002) compared to the healthy group. During backward walking there was a significant increase in the vastus medialis obliquus and adductor longus muscle activity of the patellofemoral pain syndrome group compared to the control group (P=0.003, 0.001) respectively.

Conclusions:

Clinicians should consider backward walking training to increase the muscle strength of knee extensors and hip abductors when developing rehabilitation programmes for patients with patellofemoral pain syndrome.

The effectiveness of backward walking as a treatment for people with gait impairments: a systematic review and meta-analysis

OBJECTIVE:

To investigate the effectiveness of backward walking in the treatment of people with gait impairments related to neurological and musculoskeletal disorders.

DESIGN:

Systematic review and meta-analysis of randomized and quasi-randomized control studies.

DATA SOURCES:

Searched from the date of inception to March 2018, and included PubMed, Scopus, Cochrane Library, PEDro, CINAHL, and the MEDLINE databases.

METHODS:

Investigating the effects of backward walking on pain, functional disability, muscle strength, gait parameters, balance, stability, and plantar pressure in people with gait impairments. The PEDro scale was used to assess the quality. Similar outcomes were pooled by calculating the standardized mean difference.

RESULTS:

Of the 21 studies (neurological 11 and musculoskeletal 10), 635 participants were included. The average PEDro score was 5.4/10. The meta-analysis demonstrated significant standardized mean difference values in favour of backward walking, with conventional physiotherapy treatment for two to four weeks to reduce pain (-0.87) and functional disability (-1.19) and to improve quadriceps strength (1.22) in patients suffering from knee osteoarthritis. The balance and stability in cases of juvenile rheumatoid arthritis, and gait parameters and muscle strength in anterior cruciate ligament injury improved significantly when backward walking was included as an exercise. There was no significant evidence in favour of backward walking in any of the other conditions.

CONCLUSION:

The systematic review and meta-analysis suggests that backward walking with conventional physiotherapy treatment is effective and clinically worthwhile in patients with knee osteoarthritis. Insufficient evidence was available for the remaining gait impairment conditions and no conclusions could be drawn.

Kinematic Adaptations of Forward And Backward Walking on Land and in Water

The aim of this study was to compare sagittal plane lower limb kinematics during walking on land and submerged to the hip in water. Eight healthy adults (age 22.1 ± 1.1 years, body height 174.8 ± 7.1 cm, body mass 63.4 ± 6.2 kg) were asked to cover a distance of 10 m at comfortable speed with controlled step frequency, walking forward or backward. Sagittal plane lower limb kinematics were obtained from three dimensional video analysis to compare spatiotemporal gait parameters and joint angles at selected events using two-way repeated measures ANOVA. Key findings were a reduced walking speed, stride length, step length and a support phase in water, and step length asymmetry was higher compared to the land condition (p<0.05). At initial contact, knees and hips were more flexed during walking forward in water, whilst, ankles were more dorsiflexed during walking backward in water. At final stance, knees and ankles were more flexed during forward walking, whilst the hip was more flexed during backward walking. These results show how walking in water differs from walking on land, and provide valuable insights into the development and prescription of rehabilitation and training programs.

The Effects of Backwards Running Training on Forward Running Economy in Trained Males

Backwards running (BR) results in greater cardiopulmonary response and muscle activity compared with forward running (FR). BR has traditionally been used in rehabilitation for disorders such as stroke and lower leg extremity injuries, as well as in short bursts during various athletic events. The aim of this study was to measure the effects of sustained backwards running training on forward running economy in trained male athletes. Eight highly trained, male runners (26.13 ± 6.11 years, 174.7 ± 6.4 cm, 68.4 ± 9.24 kg, 8.61 ± 3.21% body fat, 71.40 ± 7.31 ml·kg(-1)·min(-1)) trained with BR while harnessed on a treadmill at 161 m·min(-1) for 5 weeks following a 5-week BR run-in period at a lower speed (134 m·min(-1)). Subjects were tested at baseline, postfamiliarized, and post-BR training for body composition, a ramped VO2max test, and an economy test designed for trained male runners. Subjects improved forward running economy by 2.54% (1.19 ± 1.26 ml·kg(-1)·min(-1), p = 0.032) at 215 m·min(-1). VO2max, body mass, lean mass, fat mass, and % body fat did not change (p > 0.05). Five weeks of BR training improved FR economy in healthy, trained male runners without altering VO2max or body composition. The improvements observed in this study could be a beneficial form of training to an already economical population to improve running economy.

Metabolic costs and rating of perceived exertion during backward walking in water and on dry land

The purpose of this study was to compare metabolic costs, rating of perceived exertion (RPE), and stride frequency during backward walking in water and on land. The walking speeds in water were set to be half of those on land. There was no significant difference in metabolic costs and RPE between backward walking in water with a current and on land, at slow and moderate speeds (P > 0.05). However, at the fast speed (i.e., 3.0 and 6.0 km · h(-1) for water and land, respectively), the metabolic costs and RPE during backward walking on land were significantly higher than when walking backward in water with a current (P < 0.05). With regard to backward walking at faster speeds, if the walking speed in water with a current is set at half the speed on land, then the speed will be inadequate for inducing metabolic costs and RPE that are similar to those produced on land.

The effect of different types of walking on dual-task performance and task prioritization among community-dwelling older adults

BACKGROUND

The ability to safely conduct different types of walking concurrently with a cognitive task (i.e., dual task) is crucial for daily life. The contribution of different walking types to dual-task performance has not yet been determined, nor is there agreement on the strategies that older adults use to divide their attention between two tasks (task prioritization).

OBJECTIVES

To compare the effect of walking in three different directions (forward, backward, and sideways) on dual-task performance and to explore the strategies of older adults to allocate their attention in response to different motor task demands.

DESIGN

A cross-sectional study.

SUBJECTS

Thirty-two (22 female) community-dwelling older adults (aged 72.7±5.7 years).

METHODS

Subjects randomly conducted single and dual task: walking to three directions separately, cognitive tasks separately, and combination of the two.

RESULTS

Walking forward was the least demanding task, during single (FW < BW, SW) (P < .001) and dual tasks (FW < BW < SW) (P < .001). The calculation of DTC revealed the same pattern (P < .001). DTC of the cognitive tasks was not significantly different among the three walking types.

CONCLUSIONS

The decline mainly in the motor performance during dual task indicates that participants prioritized the cognitive task. These findings challenge the "posture first" paradigm for task prioritization.

Monopolar electromyographic signals recorded by a current amplifier in air and under water without insulation

It was recently proposed that one could use signal current instead of voltage to collect surface electromyography (EMG). With EMG-current, the electrodes remain at the ground potential, thereby eliminating lateral currents. The purpose of this study was to determine whether EMG-currents can be recorded in Tap and Salt water, as well as in air, without electrically shielding the electrodes. It was hypothesized that signals would display consistent information between experimental conditions regarding muscle responses to changes in contraction effort. EMG-currents were recorded from the flexor digitorum muscles as participant's squeezed a pre-inflated blood pressure cuff bladder in each experimental condition at standardized efforts. EMG-current measurements performed underwater showed no loss of signal amplitude when compared to measurements made in air, although some differences in amplitude and spectral components were observed between conditions. However, signal amplitudes and frequencies displayed consistent behavior across contraction effort levels, irrespective of the experimental condition. This new method demonstrates that information regarding muscle activity is comparable between wet and dry conditions when using EMG-current. Considering the difficulties imposed by the need to waterproof traditional bipolar EMG electrodes when underwater, this new methodology is tremendously promising for assessments of muscular function in aquatic environments.

Early aquatic physical therapy improves function and does not increase risk of wound-related adverse events for adults after orthopedic surgery: a systematic review and meta-analysis

OBJECTIVES

To investigate whether early postoperative aquatic physical therapy is a low-risk and effective form of physical therapy to improve functional outcomes after orthopedic surgery.

DATA SOURCES

Databases MEDLINE, CINAHL, AMED, Embase, and PEDro were searched from the earliest date available until October 2011. Additional trials were identified by searching reference lists and citation tracking.

STUDY SELECTION

Controlled trials evaluating the effects of aquatic physical therapy on adverse events for adults <3 months after orthopedic surgery. Two reviewers independently applied inclusion and exclusion criteria, and any disagreements were discussed until consensus could be reached. Searching identified 5069 potentially relevant articles, of which 8 controlled trials with 287 participants met inclusion criteria.

DATA EXTRACTION

A predefined data extraction form was completed in detail for each included study by 1 reviewer and checked for accuracy by another. Methodologic quality of included trials was assessed independently by 2 reviewers using the PEDro scale.

DATA SYNTHESIS

Pooled analyses were performed using random effects model with inverse variance methods to calculate standardized mean differences (SMDs) and 95% confidence intervals (CIs) (continuous outcomes) and risk difference and 95% CIs (dichotomous outcomes). When compared with land-based physical therapy, early aquatic physical therapy does not increase the risk of wound-related adverse events (risk difference=.01, 95% CI -.05 to .07) and results in improved performance of activities of daily living (SMD=.33, 95% CI=.07-.58, I(2)=0%). There were no significant differences in edema (SMD=-.27, 95% CI=-.81 to .27, I(2)=58%) or pain (SMD=-.06, 95% CI=-.50 to .38, I(2)=32%).

CONCLUSIONS

After orthopedic surgery aquatic physical therapy improves function and does not increase the risk of wound-related adverse events and is as effective as land-based therapy in terms of pain, edema, strength, and range of motion in the early postoperative period.

Vertical reaction forces and kinematics of backward walking underwater

The aim of this study was to compare the first and second peaks of the vertical ground reaction force (VGRF) and kinematics at initial contact (IC) and final stance (FS) during walking in one of two directions (forward×backward) and two environments (on land×underwater). Twenty-two adults (24.6±2.6 years) walking forward (FW) and backward (BW) on a 7.5m walkway with a central force plate. Underwater immersion was at the height of the Xiphoid process. Ten trials were performed for each condition giving a total of 40 trials where the VGRF and kinematic data were recorded. Two-way repeated measures analysis of covariance was used with a combination of environment and direction of walking: FW on land, FW underwater, BW on land and BW underwater (entered as between-subjects factor) and repeated measures of VGRF peaks (first and second) or angles (at IC and FS). Walking velocity was included as a covariate. Both VGRF peaks were reduced when participants walked underwater compared to on land (p<.001). For BW, in both environments, the second peak was lower than the first (p<.001; for both). During BW at IC the ankle is more dorsiflexed and the knee is more flexed, both on land and underwater. At FS, there was no difference between the ankle angle for FW and BW in both environments. At IC, in FW and BW the knee and hip are more flexed underwater. BW underwater involves a lower VGRF and more knee and hip flexion than BW on land.

Effects of aquatic backward locomotion exercise and progressive resistance exercise on lumbar extension strength in patients who have undergone lumbar diskectomy

OBJECTIVE

To compare the effects of aquatic backward locomotion exercise and progressive resistance exercise with a machine on lumbar extension strength in patients who have undergone diskectomy for a lumbar disk herniation.

DESIGN

Prospective comparative study.

SETTING

Department of Kinesiology at a state university.

PARTICIPANTS

Male patients (N=30) with disk herniation at spinal levels L3 to S1 completed this study as subjects.

INTERVENTION

After the diskectomy for a lumbar disk herniation, all patients had 6 weeks of rest time. At the end of the rest period, the aquatic backward locomotion exercise and progressive resistance exercise groups, respectively, started first 6 weeks of underwater training and lumbar extension training twice per week. After completion of the first 6-week training, subjects participated in a second 6-week training. After the whole 12-week training, subjects had no training for 6 weeks (detraining) and a follow-up 6-week training (retraining). The control (CON) group did not undergo any training.

MAIN OUTCOME MEASURES

For each test, maximum voluntary isometric lumbar extension strength was measured in 7 trunk positions (72 degrees , 60 degrees , 48 degrees , 36 degrees , 24 degrees , 12 degrees , and 0 degrees of the trunk angle).

RESULTS

The progressive resistance exercise and aquatic backward locomotion exercise groups showed increases in lumbar extension strength after the first 6-week training, although they were not statistically different from the CON group. After a second 6-week training, the progressive resistance exercise and aquatic backward locomotion exercise groups showed statistically significant increases in their strength levels as compared with the CON group. After the detraining period, the strength levels of the progressive resistance exercise and aquatic backward locomotion exercise groups did not statistically differ from the CON group. After the retraining period, the progressive resistance exercise and aquatic backward locomotion exercise groups showed increases in their strength levels, which were different from that of the CON group.

CONCLUSIONS

The results obtained suggested that the aquatic backward locomotion exercise is as beneficial as progressive resistance exercise for improving lumbar extension strength in patients after lumbar diskectomy surgery.

Comparison of maximal and spontaneous speeds during walking on dry land and water

The aim of this study was to quantify spontaneous and maximal speeds on dry land and in water, in four modalities of walking [forward (F), backward (B) and lateral walking (L)], with chest immersion level. Lateral walking was studied with the upper limbs of the subject alongside the body with hands placed on the lateral face of the thighs (L1) and upper limbs tightened behind the back with the hands joined (L2). 16 males (age 22.8+/-1.8 years, height 178.1+/-6.1cm, body mass 73.5+/-6.6 kg) and 15 females (age 22.8+/-2.1 years, height 171.5+/-5.8 cm, body mass 69.2+/-9.3 kg) were evaluated using the four modalities of walking on dry land and in water. The speed increments between spontaneous and maximal speeds on dry land for F, B and L1 and L2 were 60.2%, 60.9%, 64.3% and 65.3% for males and 47.3%, 48.3%, 44.5% and 53.1% for females. In the water, these variation values for F, B, L1 and L2 for males were 44.6%, 26.1%, 48.8%, and 42.1%. The values for females were 31.7%, 21.6%, 32.8%, and 34.6%. Spontaneous and maximal speeds of walking were substantially reduced in water with the chest immersed, compared to speeds on dry land for the four modalities and the two genders. These findings may be used by therapists who utilize the various modalities of walking in aquatherapy.

Physiological and perceptual responses to backward and forward treadmill walking in water

We compared physiological and perceptual responses, and stride characteristics while walking backward in water with those of walking forward in water. Eight males walked on an underwater treadmill, immersed to their xiphoid process level. Oxygen uptake ((.)V(O2)), respiratory exchange ratio (R), heart rate (HR), minute ventilation ((.)V(E)), blood lactate concentration (BLa), ratings of perceived exertion (RPE: for breathing and legs, RPE-Br and RPE-Legs, respectively), blood pressure (for systolic and diastolic pressures, SBP and DBP, respectively), and step frequency (SF) were measured. In addition, step length (SL) was calculated. (.)V(O2), R, HR, V (E), BLa, RPE-Br, RPE-Legs, and SBP were significantly higher while walking backward in water than when walking forward in water (P<0.05). Furthermore, SF was significantly higher (P<0.001) and SL was significantly lower (P<0.001) while walking backward in water, compared to walking forward in water. These results indicate that walking backward in water elicits higher physiological and perceptual responses than those produced when walking forward in water at the same speed.

Caminhada em ambiente aquático e terrestre: revisão de literatura sobre a comparação das respostas neuromusculares e cardiorrespiratórias

O objetivo deste estudo foi realizar uma revisão de literatura sobre a comparação das respostas neuromusculares e cardiorrespiratórias durante a caminhada em meio aquático e em meio terrestre. As respostas foram apresentadas para a caminhada em piscina rasa e para a caminhada em piscina funda. Em relação à caminhada em piscina rasa, as respostas neuromusculares (sinal EMG) e cardiorrespiratórias (FC e VO2) são muito dependentes da velocidade do exercício. As respostas neuromusculares podem ser menores no meio aquático quando a velocidade da caminhada é menor nesse ambiente. Por outro lado, quando o exercício é realizado com velocidades similares, a atividade dos músculos propulsores pode ser superior durante a caminhada aquática. Da mesma forma, respostas cardiorrespiratórias maiores são registradas no exercício aquático quando velocidades similares de caminhada são utilizadas. Contudo, com velocidades menores, essas respostas são semelhantes ou menores que as encontradas em meio terrestre. No que diz respeito à caminhada em piscina funda, as respostas neuromusculares diferem daquelas encontradas durante a caminhada em meio terrestre devido à ausência das forças de reação com o solo. Essa característica possivelmente modifica os músculos envolvidos na produção de força propulsiva nesse exercício. Além do mais, durante a caminhada em piscina funda, as respostas cardiorrespiratórias parecem sempre mais baixas devido à grande redução no peso hidrostático e à menor atividade dos músculos posturais e pela utilização do cinturão flutuador nessa modalidade.

Muscle activation, cardiorespiratory response, and rating of perceived exertion in older subjects while walking in water and on dry land

This study compared the muscle activities, cardiorespiratory responses, and ratings of perceived exertion (RPE) of nine older individuals while walking in water with those obtained while walking on dry land. Electromyography, stride frequency (SF), stride length (SL), oxygen uptake (V O(2)), heart rate (HR), RPE (for breathing and legs, RPE-Br and RPE-Legs, respectively), and blood lactate concentration (BLa) were measured. There were no significant differences in the V O(2), HR, RPE-Br, RPE-Legs or BLa while walking in water and on dry land (moderate and fast speeds). Both in water and on dry land, the V O(2)-HR, V O(2)-walking speed, and HR-walking speed relationships were significantly correlated. The SF and SL while walking in water were significantly lower than on dry land. The %MVCs while walking in water were all significantly lower than on dry land within each speed condition. Conversely, the V O(2), HR, RPE-Br and RPE-Legs, BLa, SL, and %MVC (the rectus femoris, vastus medialis, biceps femoris, and gastrocnemius) while walking in water were significantly higher than on dry land at the same speeds. In conclusion, walking in water elicits higher muscle activities, higher cardiorespiratory responses, and increased perceived exertion levels in older adults than walking on dry land at the same speed.