Intermittent Cervical Traction Research Articles

The effect of cervical traction on stabilometric parameters in cervical radiculopathy patients: A randomized crossover study.

Cervical traction is effective on pain and function in patients with cervical radiculopathy but its effectiveness on balance disorders has not yet been studied. To evaluate the effect of mechanical intermittent cervical traction (MICT) on stabilometric parameters in patients with cervical radiculopathy. This randomized crossover study assigned 20patients with cervical radiculopathy to one of the two groups: Group effective traction (ET)/sham traction (ST) (n= 10) treated firstly with ET (traction force of 12Kg) then with ST (traction force of 2Kg) with one-week interval and group ST/ET (n= 10) treated invertedly with a ST then ET. Each traction procedure was maintained for 10minutes twice separated by 5minutes of rest. Patients were assessed before and immediately after MICT procedure. Main outcome measures were stabilometric parameters: center of pressure, sway area and lateral and anteroposterior displacements using a force platform. Secondary outcome measures were pain intensity, grip strength and dizziness. ET has provided a significantly greater improvement in both groups and in the total population in terms of stabilometric parameters (p< 0.01), pain intensity, and grip strength (p< 0.05), compared to ST. MICT seems to have an immediate beneficial effect on stabilometric parameters, pain and grip strength in patients with cervical radiculopathy.

The Efficacy of Intermittent Cervical Traction in Cervical Spondylosis with Radiculopathy

Background: Degeneration of cervical spine is one of the most common causes of neck and arm pain with disability. Many studies have done regarding correlation between cervical traction and cervical spondylosis but still there is lack of data about effect ICT (intermittent cervical traction) on cervical spondylosis and radiculipathy. Methods: This prospective randomized clinical trials was performed at physical medicine &amp; Rehabilitation department, Combined Military Hospital (CMH) Dhaka and BSMMU (Vagabond sheikh mujib medical university), Dhaka over a period of six months. 80cases completed the study after selecting by consecutive sampling according to inclusion &amp; exclusion criteria. The neligible participants allocated into two groups. Group-A were managed by supervised ICT, NSAID's, therapeutic neck exercise, soft cervical collar and ADL advice. Group-B received same as A -group management except (ICT). Evaluation made at initial visit and weekly for six weeks. Assessment of the patient was done by VAS, NPRS, pain frequency score and neck ROM. Student's 't' tests, chi square tests were done to see the level of significance. “P” value &lt; 0.05 considered as significant. Results: Among the 80 patients, mean age was 45 ± 9.25 years, 65% were male and 35% were female. Maximum patients were predominantly table worker 30(37.5%) and mean BMI was 24.95 ± 1.86. After six weeks treatment VAS, NPRS, Pain frequency score shows significant difference of improvement “P” value &lt; 0.05 between two groups. Conclusion: So it is suggested that add on therapy of intermittent cervical traction with NSAID and exercise inflict significant effects in pain and functional ability in patients with cervical spondylosis with radiculipathy.

Comparison Of the Effectiveness of Maitland Manipulation of Thoracic Spine Versus Grade I And II Maitland Mobilization of Cervical Spine on Pain Intensity and Functional Status in Patients of Cervical Radiculopathy

Cervical radiculopathy (CR) is a most reported pathological problem mainly due to herniated disc material causing nerve compression or the formation of osteophytes. This impingement specifically causes cervical pain radiating to arm, numbness, and sensory deficit. It also affects the motor function of the neck and upper extremities. Objectives: To evaluate the comparative effectiveness of Maitland manipulation of thoracic spine versus grade I and II Maitland mobilization of cervical spine on Pain, intensity, and functional status in patients of cervical radiculopathy. Methods: Total 32 patients suffering from cervical radiculopathy were randomly assigned to receive Maitland manipulation on thoracic spine along with Conventional Physiotherapy (intermittent cervical traction, strengthening exercises) in Group A(n=16) and Maitland mobilization on cervical spines along with Conventional Physiotherapy in Group B (n=16). Total treatment sessions given to each group was 9 (3 sessions per week). To measure outcome numeric pain rating scale (NPRS) and neck disability index (NDI) questionnaire was used. Data collection was done at the beginning and post-treatment. Results: The study revealed that the mean age of patients was 47.59 with a range minimum of 27 years to a maximum of 59 years. Comparison of post-treatment of both groups showed mean NPRS score in group A (Maitland thoracic spine manipulation) was 4.56± 1.031 and group B (Maitland cervical spine mobilization) was 6.12± 0.50, while post-treatment NDI score group A was 22.44± 10.09 and group B was 36.88± 8.437 with p=0.000 that was p&lt;0.05. Conclusion: The study concluded that both Maitland thoracic spine manipulation and Maitland cervical spine mobilization techniques have similar effects in reducing cervical radiculopathy and increasing active range of motion. However, Maitland thoracic spine manipulation showed better results in neck pain reduction and improved functional status on the comparison.

Comparing Mulligan Mobilization and Neural Mobilization Effects in Patients with Cervical Radiculopathy

Background Mulligan mobilization and neural mobilization have already made a mark and have been found effective in reducing pain disability and in improving range of motion in patients with cervical radiculopathy. Objective The present study was intended to compare the effects of Mulligan mobilization versus neural mobilization in cervical radiculopathy.Methods Thirty patients with cervical radiculopathy were conveniently assigned to two groups ndash Group A n15 were treated with Mulligan mobilization while Group B n15 were treated with neural mobilization. Intermittent cervical traction was used as a common treatment for both the groups. Treatment dosage for both groups was seven sessions or one week. Neck disability functional level and range of motion before and after the treatment program were evaluated by using Neck Disability Index questionnaire Patient Specific Functional Scale questionnaire and Goniometer respectively.Results In Group A amp Group B significant improvement in condition existed within the groups. There was a significant reduction in neck disability increase in functional level and increase in ROM following Mulligan and neural mobilizations. Though patients who received neural mobilization did better than patients who received Mulligan there was no significant difference between the groups. PSFS p0.572NS NDI p0.269NS ROM Flexion p0.776NS extension p0.302NS lateral flexion ndash right p0.282NS lateral flexion ndash left p0.877NS side rotation ndash left p0.72NS were noted.Conclusion Neural mobilization showed better results than Mulligan mobilization in the management of cervical radiculopathy. However there was no significant difference between the groups.Keywords Cervical radiculopathy Mulligan mobilization Neural mobilization Neck disability Functional level.

Effect of nerve mobilization with intermittent cervical segment traction on pain, range of motion, endurance, and disability of cervical radiculopathy

Effect of nerve mobilization with intermittent cervical segment traction on pain, range of motion, endurance, and disability of cervical radiculopathy

H-reflex latency changes after combined application of traction and neural mobilization in cervical radiculopathy

BackgroundCervical radiculopathy is a pathology of the cervical nerve root and mostly caused by a cervical disk herniation leading to chronic pain and disability.ObjectivesThis study was conducted to show the effect of the combined application of intermittent cervical traction with median nerve mobilization on flexor carpi radialis (FCR) muscle H-reflex latency of median nerve in patients with unilateral cervical radiculopathy due to disk lesion in a pre-post design.MethodsFifteen patients (10 females and 5 males) with a mean age of 38.07 ± 5.85 years received simultaneous application of intermittent cervical traction and median nerve mobilization. Six sessions were given every other day for 2 weeks. Also, patients perormed chin in exercises and upper back extension with scapular retraction. FCR H-reflex latency was measured pre- and post-treatment.ResultsStatistical analysis showed that there was a significant reduction of H-reflex latency at post-treatment in comparison to pretreatment (t = 5.447, p value = 0.0001*).ConclusionSimultaneous application of intermittent cervical traction and median nerve mobilization are effective in improving FCR H-reflex latency in patients with unilateral cervical radiculopathy.

Effectiveness of static and intermittent cervical tractions in the management of patients with chronic non-specific neck pain: A pilot randomised trial

Background: Physiotherapists commonly employ cervical traction for patients with neck pain. There is a dearth of literature on the effects of static and intermittent cervical traction on pain, range of motion and disability among patients with chronic non-specific neck pain. Therefore, this study aims to compare the effect of static and intermittent cervical traction on pain, disability and range of motion among patients with chronic, non-specific neck pain.Methods: Twenty-four participants were randomised into two groups – Static and Intermittent cervical traction respectively. They were recruited from the Aminu Kano Teaching Hospital and the National Orthopaedic Hospital in Dala-Kano, Kano. Both groups received exercises and infrared treatment, in addition to Static and Intermittent cervical traction. Outcomes were assessed at the baseline and at the end of six weeks of intervention. Pain was assessed through the use of a Visual Analogue Scale, neck disability through a Neck Disability Index questionnaire and cervical range of motion with a goniometer. Data was analysed using descriptive and inferential statistics, and alpha was set at &lt;0.05.Results: The mean ages of the participants were 46.00±7.81 and 36.00±15.02 for the groups Static and Intermittent respectively. Both groups were comparable at baseline (p&gt;0.05). Both Static and Intermittent cervical traction was effective in reducing the disability (p&lt;0.05) and pain (p&lt;0.05). There was no significant difference between the groups at six weeks in terms of pain, disability and range of motion (P&gt;0.05).Conclusion and recommendation: Both Static and Intermittent cervical traction effectively manages chronic, non-specific neck pain and neither is superior to the other.

A Comparative study on Alteration of blood Pressure During Mechanical Intermittent and Continuous Cervical traction

A Comparative study on Alteration of blood Pressure During Mechanical Intermittent and Continuous Cervical traction

The Effectiveness of Cervical Traction and Exercise in Decreasing Neck and Arm Pain for Patients With Cervical Radiculopathy: A Critically Appraised Topic

Clinical Question:Is there evidence to suggest intermittent cervical traction with cervical and scapular strengthening exercises is more effective in decreasing neck and arm pain when compared with cervical and scapular strengthening exercises alone in nonoperative patients with cervical radiculopathy?Clinical Bottom Line:There is currently inconsistent, high-quality evidence that suggests that the use of intermittent cervical traction in addition to strengthening exercises is more effective at decreasing pain in nonoperative patients with cervical radiculopathy when compared with strengthening alone. Future research should continue to examine long-term outcomes associated with cervical radiculopathy patients who use intermittent cervical traction as an intervention.

Intermittent Cervical Traction for Treating Neck Pain: A Meta-analysis of Randomized Controlled Trials.

A meta-analysis. The aim of this study was to perform a comprehensive search of current literature and conduct a meta-analysis of randomized controlled trials (RCTs) to assess the neck pain relieving effect of intermittent cervical traction (ICT). Neck pain is a common and disabling problem with a high prevalence in general population. It causes a considerable burden on the health care system with a substantial expenditure. ICT is a common component of physical therapy for neck pain in the outpatient clinic. However, the evidence regarding the effectiveness of ICT for neck pain is insufficient. Data were obtained from the PubMed, Cochrane Library, Embase, and Scopus databases from the database inception date to July 02, 2016. RCTs reporting the effects of ICT on neck pain, including those comparing the effects of ICT with those of a placebo treatment, were included. Two reviewers independently reviewed the studies, conducted a risk of bias assessment, and extracted data. The data were pooled in a meta-analysis by using a random-effects model. The meta-analysis included seven RCTs. The results indicated that patients who received ICT for neck pain had significantly lower pain scores than those receiving placebos did immediately after treatment (standardized mean difference = -0.26, 95% confidence interval = -0.46 to -0.07). The pain scores during the follow-up period and the neck disability index scores immediately after treatment and during the follow-up period did not differ significantly. ICT may have a short-term neck pain-relieving effect. Some risks of bias were noted in the included studies, reducing the evidence level of this meta-analysis. Additional high-quality RCTs are required to clarify the long-term effects of ICT on neck pain. 1.

A randomized controlled trial of intermittent Cervical Traction in sitting Vs. Supine position for the management of Cervical Radiculopathy.

Objective:To compare the effectiveness of intermittent cervical Traction in sitting vs. supine position for the management of cervical radiculopathyMethods:A randomized clinical trial was done to compare pain and disability modification of cervical radiculopathy patients by using cervical traction in sitting and supine positions. Forty patients (males and females aged between 18-60 years with chronic cervical radiculopathy) were recruited for the trial. Participants were randomized into two homogeneous groups by dice method. The Group-A (n=20) received 3-weeks of intermittent cervical traction in sitting position along with Transcutaneous Electric Nerve Stimulation (TENS) and hot pack. The Group-B (n=20) received the same treatment except the intermittent cervical traction that was applied in supine position. Participants were assessed two times: at baseline (week 0) and at the termination of rehabilitation (week 3). Neck disability index was used to collect the data before and after the treatment.Results:The mean age of the patients was 43.15±8.99 vs. 48.80±6.89 years in Group-A vs. Group-B respectively. Mean (±S.D.) weight of the patients was 74.75±12.11 vs. 74.60±11.24 kg in Group-A vs. Group-B respectively. Mean Neck Disability Index score at start of treatment was 30.30±7.46 vs. 30.75±7.85 in Group-A and Group-B respectively. There was a significant difference in Group-A and Group-B regarding aggregate NDI score at the end of treatment (19.45±7.12 vs. 11.05±4.40; p<0.0001).Conclusion:Supine position is better choice for applying cervical traction as compared to sitting position for the management of cervical radiculopathy comparing post interventional NDI score.

Effect of Intermittent Cervical Traction on Blood Pressure and Pulse Rate in the Subjects with Cervical Spondylosis

Effect of Intermittent Cervical Traction on Blood Pressure and Pulse Rate in the Subjects with Cervical Spondylosis

Comparison of Maitland Thoracic Spine Manipulation Versus Maitland Cervical Spine Mobilization in Chronic Unilateral C6 – C7 Cervical Radiculopathy

Background: Radicular pains are very common in cervical region due to C6 – C7 nerve root involvement which results discomfort and restriction of mobility of upper and lower segments of cervical and thoracic spine. A lot of evidences about non-operative treatments have been derived for managing cervical radiculopathies with a little documentation of manual therapy. So, in this study, Maitland concept of manipulation and mobilization at two different regions of spine (thoracic and cervical) respectively, was used to see the change in pain reduction and restoration of normal functional abilities.Methodology: A study design of Comparative single blinded, randomized control clinical trials was used. 100 patients having chronic unilateral C6 – C7 cervical radiculopathy’s symptoms due to disc prolapsed, divided into two groups with simple random sampling as guided per-consolidated standards of reporting trials (CONSORT) guidelines were used. First group was managed with Maitland thoracic spine manipulation (MTSM), mechanical intermittent cervical traction (MICT) for 10 minutes and regime of strengthening exercises (SE) and second group was managed with Maitland cervical spine mobilization (MCSM), MICT and SE. The duration of treatment was four weeks at the rate of three times in one week. Two outcome measures numeric pain rating scale (NPRS) and Neck disability index (NDI) questionnaire were used for evaluation and investigation. Data was collected at start, after two and after four Weeks’s treatment. Independent T test with extension of Levene’s test was used with 0.05% level of confidence.Results: The calculated p value for NPRS and NDI for group A (MTSM) was P = 0.000which was less than 0.05 having validation of significant changes. So, we reject our Null hypothesis that MTSM is more effective than MCSM.Conclusion: The result shows that MTSM and MC-SM were effective techniques for pain reduction and functional abilities restoration. However, the subjects of first group with MTSM, MICT and SE presented better progress in reduction of neck ache and refining functional status during comparison.

Effectiveness of neural mobilization with intermittent cervical traction in the management of cervical radiculopathy: A randomized controlled trial

BackgroundThe effectiveness of both neural mobilization and intermittent cervical traction (ICT) has been previously explored in some studies of generally low methodological quality. However, the effect of simultaneous application of these techniques in people with cervical radiculopathy (CR) has not been previously investigated. AimTo investigate the effect of neural mobilization with simultaneously applied ICT on pain, disability, function, grip strength and cervical range of motion in patients with CR. DesignRandomized, controlled, assessor-blinded, clinical trial. MethodsParticipants (n = 42) diagnosed with unilateral CR were randomly allocated to intervention (neural mobilization combined with ICT, n = 21) or control (n = 21) groups. Participants in the intervention group were asked to attend for 12 treatment sessions to receive 6 sets of 60s grade II–IV ICT with simultaneously applied ‘slider’ neural mobilizations with median nerve bias. Participants randomized to the control group did not receive any type of treatment and were asked to avoid prescription or over-the-counter analgesia or anti-inflammatory medication. The Neck Disability Index (NDI), the Patient-Specific Functional Scale (PSFS), the Numeric Pain Rating Scale (NPRS), and measures of grip strength (GS) and cervical spine active range of motion (CSAROM) were administered at baseline and at 4-weeks. ResultsThe intervention group demonstrated significant improvements in NDI scores (mean difference = −16.95; 95% CI = −22.47 to −11.43, ES = 0.42), PSFS scores (mean difference = 2.88; 95% CI = 2.33 to 3.43, ES = 0.66), NPRS scores (mean difference = −3.74; 95% CI = −4.92 to −2.96, ES = 0.37), GS (mean difference = 1.87 kg; 95% CI = 0.51 to 3.23; ES = 0.07), and CSAROM (except for lateral flexion), compared to the control group where significant changes were not detected. ConclusionNeural mobilization with simultaneous ICT can improve, pain, function, disability, grip strength and cervical range of motion in people with CR. Further clinical trials comparing neural mobilization with cervical traction to other standard interventions are justified.

Vertigo, can it be redefined?

Background &amp; Objectives- &#x0D; Vertigo, a clinical symptom complex is not infrequent in our patients. Its diagnosis too is controversial. Majority of these cases run from hospital to clinics, some times to Otolaryngologists to get rid of this bizarre experience. Sometimes they get benefit but otherwise they experience a destitute life.&#x0D; Our aim was to treat them by Physical Therapy in the light of Cervical Spondylosis that is commonly associated with vertigo.&#x0D; Material &amp; Methods-&#x0D; This is a prospective case study done in PMR department (OPD) of a teaching institute over a period of 6 months time period. 20 OPD patients of both sexes (14 ladies and 6 gents) with definite Cervical Spondylosis along with complain of vertigo or dizziness, pain at cervical spine were accounted for the study. Only extreme aged persons or patients with other major co-morbidity were excluded. These 20 patients were treated with conventional Physical Therapy for CS. Medications were prescribed as and when required.&#x0D; Results-&#x0D; After Physical Therapy, that included lifestyle modification, isometric cervical exercise, intermittent cervical traction, application of Therapeutic Ultrasound (UST) to cervical region and proper posture care of cervical spine along with use of cervical orthosis (where needed), majority of the patients become symptom free.&#x0D; Conclusion- &#x0D; Physical Therapy may be considered as an alternative method of treatment of Vertigo patients, who are otherwise not responding satisfactorily to pharmaceutical agents.

Manual therapy and segmental stabilization in the treatment of cervical radiculopathy

Abstract Introduction: Cervical radiculopathy (CR) is one of the diseases that most affect the cervical spine, causing radicular symptoms in the ipsilateral limb. Conservative treatment aim recover of both mechanical and physiological functions through neural mobilization techniques, along with the activation of the deep neck flexors with cervical segmental stabilization, combining techniques of joint mobilization and manipulation, which seeks mobility improvement of crucial areas of the cervical spine. The objective of this study was to evaluate a multimodal treatment to enhance the outcomes of conservative care in patients diagnosed with CR. Methods: The sample consisted of 11 patients with CR, between 21 and 59 years old, 3 female and 8 male. It was recorded the Visual Analogue Scale (VAS) for pain, the Functional Development of the Neck Pain and Disability Scale (NPDS) and the goniometry during shoulder abduction. The intervention plan was composed by neural mobilization, intermittent cervical traction, pompages, stretching, myofascial inhibition techniques, manipulative techniques and cervical segmental stabilization exercises. After 12 weeks of treatment, subjects underwent a new evaluation process. Results: Before the treatment, subjects reported an average pain of 7 (± 1.48) in VAS, whose dropped to average 1.18 (± 1.99) (p &lt; 0.01). Functional disability evaluated in NPDS was 36 (± 10.95) before treatment decreasing to 11.45 (± 9.8) (p &lt; 0.01) after the treatment. Range of motion of the ipsilateral upper limb was restores by increasing from 9.2° (± 8.2) to 137° (± 24.4) (p &lt; 0.01). Conclusion: The proposed treatment approach was effective, significantly improving the results of analgesia and functional disability a series of cases of patients diagnosed with cervical radiculopathy. {#}

A Comparative Study on the Effects of Two Different Positions of Intermittent Cervical Traction in Cervical Radiculopathy

A Comparative Study on the Effects of Two Different Positions of Intermittent Cervical Traction in Cervical Radiculopathy

The efficacy of ultrasound-guided extracorporeal shockwave therapy in patients with cervical spondylosis and nuchal ligament calcification

We investigated the effects of extracorporeal shockwave therapy (ESWT) on the rehabilitation of cervical spondylosis with nuchal ligament (NL) calcification under X-ray and ultrasound guidance. Sixty patients with cervical spondylosis and calcification of NL were selected and randomly assigned to three groups: A, B, and C. Patients in Group A received rehabilitation with 20 minutes of hot packs and underwent 15 minutes of intermittent cervical traction three times/week for 6 weeks. Patients in Group B received the same rehabilitation as those in Group A and ESWT (2000 impulses, 0.27 mJ/mm2) over the calcified NL guided by X-ray image. Patients in Group C received the same treatment as those in Group B, but the ESWT was guided by musculoskeletal sonography. The therapeutic effects were evaluated by: changes in range of motion (ROM) of the cervical spine including flexion, extension, lateral bending, and rotation; visual analog pain scale; and Neck Disability Index before and after treatment and at follow up 3 months later. We found a significant reduction in pain in each treated group after treatment and at follow up. However, patients in Groups B and C showed more improvements in ROM and neck pain relief after treatment and a decrease in Neck Disability Index. Furthermore, patients in Group C showed better cervical ROM at follow up than Group B. ESWT is an adjuvant treatment in the management of cervical spondylosis with calcification of NL and ultrasound-guided ESWT results in more functional improvements.

Neural Mobilization for Brachial Neuralgia among Cellulo-Teno Periosteo Myalgic Syndrome (CTPMS) Patients

Neural Mobilization is an effective tool in the management of the neural sensitivity disorders. This can be used to treat the brachial neuralgia among Cellulo Teno Periosteal Myalgic Syndrome (CTPMS) patients. The specific objective of the study was to evaluate the efficacy of neural mobilization in brachial neuralgia and role neural mobilization in improving the cervical ROM is also evaluated. A total of twenty samples participated in the study. Reduction in pain intensity was significant in both the groups. Gaining the mechanical connection of the nervous system may also assist patients in accepting why movement of body parts distant from the site of symptoms may be used as a treatment approach to mobilize neural tissues. Neural tissue mobilization techniques are passive or active movements that focus on restoring the ability of the nervous system to tolerate the normal compressive, friction, and tensile forces associated with daily and sport activities. Question: Role of Nerve Mobilization in Brachial Neuralgia among Cellulo Teno Periosteal Myalgic Syndrome Patients. Design: Pre Post Experimental Study design. Participants: Brachial neuralgia with CTPMS who have decreased cervical rotation ROM in the Age group 25-40 includes both sexes (male and female) predominantly White collar occupation. Intervention: Nerve mobilization technique for total brachial plexus ULTT1 was used as the neural mobilization tool, intermittent cervical traction & Interferential therapy. Outcome measures: Pain was measured using visual analogue scale & Cervical rotation Range of motion was measured by using the inch tape method. Results & Conclusion: The result concluded that neural mobilization is more effective than (IFT) interferential therapy while combined with (ICT) intermittent cervical traction in the re-abilitation of brachial neuralgia among CTPMS patients and hence it can be combined with intermittent cervical traction to reduce pain and improve cervical rotation ROM for brachial neuralgia patients.

Dry Needling Effects on Non-Specific Cervical Radiculopathic Pain and Dysfunction:-A Case Report

Abstract: 19 year old college student was referred to physical therapy department with signs and symptoms of seventh cervical nerve root radicupathic pain. Physical examination of cervical spine had shown that localised pain over left C6-7 junction and radiating down till the dorsal aspect of ring finger. Spurling and upper limb tension tests had shown positive a sign for cervical nerve root irritation. She was treated with intermittent cervical traction, stretching for neck muscles, mobilization for cervical and thoracic spine, and trigger point massage for the period of two week. But, the symptoms were not reduced completely and she had complaints of recurrence of radiating pain. Further examination had revealed that maximum tender points over paraspinal muscle of cervical region and altered function of cervical spine. Later she was treated with dry needling over supraspinous ligament and myofascial trigger points of cervical and shoulder muscles. The dry needling procedure was carried out for two sessions with 72 hour interval and subjective pain intensity and neck disability was assessed using Visual Analog Scale and Neck Disability Index before and after treatment. The post needling pain and neck disability score were reduced compared to before intervention pain and disability score. Pain and neck disability was assessed three months after the treatment which was also shown that sustainability of effects.