The Influence of Verbal and Tactile Feedback on Electromyographic Amplitude of the Shoulder Musculature During Common Therapeutic Exercises

2018 ◽  
Vol 27 (5) ◽  
pp. 424-430 ◽  
Author(s):  
Sean A. Jones ◽  
Derek N. Pamukoff ◽  
Timothy C. Mauntel ◽  
J. Troy Blackburn ◽  
Joseph B. Myers
Keyword(s):  
External Rotation ◽  
Tactile Feedback ◽  
Serratus Anterior ◽  
Difference Scores ◽  
Emg Amplitude ◽  
Therapeutic Benefits ◽  
Therapeutic Exercises ◽  
Significant Difference ◽  
The Difference ◽  
Shoulder Musculature

Context:Verbal and tactile feedback (VTF) during rehabilitation exercises can increase muscle activation, thus improving the therapeutic benefits. However, it is unclear which feedback method elicits the greatest electromyographic (EMG) amplitude.Objective:To determine if the addition of tactile to verbal feedback (VF) increases EMG amplitude of selected shoulder musculature during scapular plane elevation (Ys), shoulder horizontal abduction with external rotation (Ts), and scapular retraction with external rotation (Ws).Design:Repeated-measures cross-over design.Setting:Biomechanics laboratory.Participants:A total of 30 physically active adults volunteered for this study—age = 20.23 (1.25) years; height = 1.71 (0.073) m; and mass = 70.11 (15.14) kg.Interventions:Electromyography of the serratus anterior; upper, middle, and lower trapezii; and anterior and posterior deltoids was recorded during Ys, Ts, and Ws with VTF and VF alone during separate testing sessions. Participants completed baseline trials without feedback, then received VTF and VF across 2 counterbalanced sessions.Main Outcome Measures:Difference scores were calculated between prefeedback and postfeedback interventions, and the difference score between baseline measurements was used as a control. One-way analysis of variance of the difference scores was used to evaluate the influence of VTF and VF on EMG amplitude during Ys, Ts, and Ws.Results:There was a significant difference between conditions for EMG amplitude of the middle trapezius (F2,28 = 4.09,P = .02) and serratus anterior (F2,28 = 3.91,P = .03) during Ys, the middle trapezius (F2,28 = 7.82,P = .001) during Ws, and the upper (F2,28 = 3.61,P = .03) and middle trapezii (F2,28 = 5.81,P = .01) during Ts. Post hoc testing revealed that both feedback conditions elicited greater EMG amplitude compared with no feedback, but there were no significant differences between the feedback conditions.Conclusions:The addition of tactile feedback to VF does not increase EMG amplitude compared with VF alone. This study indicates that feedback, regardless of type, is more beneficial than providing no feedback, for increasing EMG amplitude.

Exploring Active and Passive Contributors to Turnout in Dancers and Non-Dancers

2015 ◽  
Vol 30 (2) ◽  
pp. 78-83 ◽  
Author(s):  
Kristen Sutton-Traina ◽  
Jo A Smith ◽  
Danielle N Jarvis ◽  
Szu-Ping Lee ◽  
Kornelia Kulig
Keyword(s):  
External Rotation ◽  
Peak Force ◽  
Ultrasound Images ◽  
Cross Sectional ◽  
Dance Training ◽  
Femoral Version ◽  
Significant Difference ◽  
Hip Abductor ◽  
The Difference ◽  
Bony Morphology

OBJECTIVE: Lower-extremity external rotation, or turnout, is a fundamental skill in dance. Active standing turnout has previously been measured using low-friction turnout disks. Turnout is influenced by passive range of motion (ROM) and strength, with passive ROM a function of bony morphology and ligamentous/capsular restraints. PURPOSE: Our study explored the relationship between standing active turnout and femoral bony morphology, hip passive ROM, and strength among dancers and non-dancers. METHODS: Cross-sectional cohort study. Twenty-three female dancers and 13 female non-dancers aged 18 to 30 yrs were recruited. Standing active turnout on reduced-friction disks, ultrasound images of femoral version, supine passive turnout, and hip abductor and external rotator strength were collected. RESULTS: Dancers demonstrated greater standing turnout (107º±18º) than non-dancers (92º±28º), but the difference was not statistically significant (p=0.054). A significant difference was found for femoral version (p<0.001), 4.7º (±2.8º) for dancers vs 12.1º (±4.6º) for non-dancers. Dancers demonstrated greater supine turnout, 102.7º±18.8º, compared to non-dancers, 84.3º±30.4º (p=0.031). Dancers were able to achieve greater peak force in turnout compared to non-dancers: 2.44±0.44 N/kg and 1.72±0.59 N/kg, respectively (p<0.0001). Supine total turnout was the best predictor of active turnout, contributing 48% of the variance (r=0.696, p<0.001). CONCLUSION: Our findings suggest supine turnout is the largest predictor for standing turnout. Investigating dancers and non-dancers independently, our finding were similar to previous studies suggesting the femoro-acetabular complex may be influenced by dance training, contributing to differences in bony morphology between dancers and non-dancers. Although strength did not significantly contribute to active standing turnout, dancers demonstrated greater peak force compared to non-dancers.

Measurement of Glenohumeral Internal Rotation in Asymptomatic Tennis Players and Swimmers

2009 ◽  
Vol 37 (5) ◽  
pp. 1017-1023 ◽  
Author(s):  
Renato Rangel Torres ◽  
João Luiz Ellera Gomes
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Control Group ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Tennis Players ◽  
Glenohumeral Internal Rotation Deficit ◽  
Significant Difference ◽  
Overhead Sports ◽  
The Difference

Background Glenohumeral internal rotation deficit, often diagnosed in players of overhead sports, has been associated with the development of secondary shoulder lesions. Hypothesis Asymptomatic players of different overhead sports will exhibit variable degrees of glenohumeral internal rotation deficit. Study Design Cross-sectional study; Level of evidence, 3. Methods Fifty-four asymptomatic male volunteers (108 shoulders) divided into 3 groups (tennis players, swimmers, control group) underwent measurements of glenohumeral internal and external rotation using clinical examination with scapular stabilization. Measurements of dominant and nondominant shoulders were compared within and between groups. Glenohumeral internal rotation deficit (GIRD) was defined as the difference in internal rotation between the nondominant and dominant shoulders. Results In tennis players, mean GIRD was 23.9° ± 8.4° (P < .001); in swimmers, 12° ± 6.8° (P < .001); and in the control group, 4.9° ± 7.4° (P = .035). Dominant shoulders showed significant difference between all groups, and the difference in internal rotation of the dominant shoulder between the group of tennis players in comparison with the control group (27.6°, P < .001) was greater than the difference in internal rotation of the dominant shoulder found in the group of swimmers compared with the control group (17.9°, P < .001). Between tennis players and swimmers, the difference in internal rotation of the dominant shoulder was 9.7° (P = .002). Conclusion Dominant limbs showed less glenohumeral internal rotation than the nondominant limbs in all groups, with the deficit in the group of tennis players about twice the deficit found for swimmers. Mean difference between limbs in the control group was less than 5°, which is within normal parameters according to most studies. There were statistically significant differences between all groups when dominant shoulders were compared with each other, differences that were not compensated by external rotation gain. Tennis players had the least range of motion, followed by swimmers.

scholarly journals Biomechanical study on the stress distribution of the knee joint after residual rotation deformity of tibial fracture

2020 ◽  
Author(s):  
Ming Li ◽  
Yanbin Zhu ◽  
Ning Wei ◽  
Wenli Chang ◽  
Zeyue Jin ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Knee Joint ◽  
Lower Limb ◽  
External Rotation ◽  
Biomechanical Study ◽  
Lower Limbs ◽  
Neutral Position ◽  
Lateral Stress ◽  
Significant Difference ◽  
The Difference

Abstract Objectives To investigate the effect of residual rotation deformity on the stress distribution of the knee joint after surgery to treat middle and upper tibial fractures. Methods Fourteen adult cadaver specimens that were preserved with formalin were included, and the tibias were randomly positioned at 0 degree, 5 degrees, 10 degrees, and 15 degrees from the line of force of the lower limb. These positions modeled deformities of 5 degrees, 10 degrees, and 15 degrees from the line of force. Low-pressure pressure-sensitive film technology measured the stress distribution of the knee joint under different degrees of rotation deformity. Results Under a vertical load of 400 N, the difference between the medial and lateral stress of the knee joint was significantly different between the different tibia deformities (P<0.05), and the medial stress of the knee joint was higher than the lateral stress. The current study showed that there were statistically significant differences in the medial stress on the knee joint at all angles (including the neutral position of 0 degrees) (F=89.753, P<0.001) . There was a statistically significant difference in the lateral stresses of the knee joint between different rotation deformities (including the neutral position of 0 degrees) (F=102.998, P<0.001). Conclusions Residual rotation deformity after fracture of middle and upper tibia can lead to poor alignment of lower limb force and change of articular contact characteristics of knee joint, especially external rotation of tibia.Therefore, orthopedic surgeons should correct the malalignment of lower limbs to the greatest extent and reduce the rotation deformity as far as possible.

Effect of Loading Devices on Muscle Activation in Squat and Lunge

2020 ◽  
Vol 29 (2) ◽  
pp. 200-205
Author(s):  
Hong-Wen Wu ◽  
Cheng-Feng Tsai ◽  
Kai-Han Liang ◽  
Yi-Wen Chang
Keyword(s):  
Tibialis Anterior ◽  
Muscle Activation ◽  
Repeated Measure ◽  
Cross Sectional ◽  
Lower Limb Injury ◽  
Muscle Strengthening ◽  
Therapeutic Exercises ◽  
Significant Difference ◽  
The Difference ◽  
Loading Devices

Context: Squats and lunges are common exercises frequently applied in muscle-strengthening and therapeutic exercises. The loading devices are often used to increase the training intensity. Objective: To determine the effect of loading devices on muscle activation in squat and lunge and to compare the differences in muscle activation between squat and lunge. Design: Cross-sectional cohort. Participants: Nineteen healthy, male, recreationally active individuals without a history of lower limb injury. Interventions: Each participant performed 10 repetitions of a squat under 5 conditions: unloaded, barbell, dumbbell, loaded vest, and kettlebell, and 10 repetitions of a lunge under 4 conditions: unloaded, barbell, dumbbell, and loaded vest. Main Outcome Measures: The electromyography signals of quadriceps, hamstrings, tibialis anterior, gastrocnemius lateralis and medialis were measured. One-way repeated-measure analysis of variance was used to compare the difference among different loading conditions. Paired t test was used to compare the difference between squat and lunge. Results: The muscle activation in the loaded conditions was significantly higher than that in nonloaded conditions in squat and lunge. Compared with the barbell, dumbbell, and loaded vest conditions, the semitendinosus showed significantly higher activation, and the tibialis anterior showed significantly lower activation in kettlebell condition in squat. No significant difference in muscle activation was found among barbell, dumbbell, and kettlebell conditions in lunge. In addition, quadriceps and hamstring activities were significantly higher in lunge than in squat. Conclusions: Muscle activation was affected by the loading devices in squat but not affected in lunge. Kettlebell squat could be suggested for targeting in strengthening medial hamstring. Progressive strengthening exercise could be recommended from squat to lunge based on sequential activation level.

Legal Update: North Dakota Supreme Court: Third Edition of Guides is “Most Current”

1999 ◽  
Vol 4 (1) ◽  
pp. 6-7
Author(s):  
James J. Mangraviti
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Measurement Techniques ◽  
Fourth Edition ◽  
Hip Motion ◽  
The Difference ◽  
The Right ◽  
Hip Flexion ◽  
Hip Rotation ◽  
Hip Extension

Abstract The accurate measurement of hip motion is critical when one rates impairments of this joint, makes an initial diagnosis, assesses progression over time, and evaluates treatment outcome. The hip permits all motions typical of a ball-and-socket joint. The hip sacrifices some motion but gains stability and strength. Figures 52 to 54 in AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, illustrate techniques for measuring hip flexion, loss of extension, abduction, adduction, and external and internal rotation. Figure 53 in the AMA Guides, Fourth Edition, illustrates neutral, abducted, and adducted positions of the hip and proper alignment of the goniometer arms, and Figure 52 illustrates use of a goniometer to measure flexion of the right hip. In terms of impairment rating, hip extension (at least any beyond neutral) is irrelevant, and the AMA Guides contains no figures describing its measurement. Figure 54, Measuring Internal and External Hip Rotation, demonstrates proper positioning and measurement techniques for rotary movements of this joint. The difference between measured and actual hip rotation probably is minimal and is irrelevant for impairment rating. The normal internal rotation varies from 30° to 40°, and the external rotation ranges from 40° to 60°.

Cranial crassicaudiasis in two coastal dolphin species from South Africa is predominantly a disease of immature individuals

2020 ◽  
Vol 139 ◽  
pp. 93-102 ◽  
Author(s):  
MF Van Bressem ◽  
P Duignan ◽  
JA Raga ◽  
K Van Waerebeek ◽  
N Fraijia-Fernández ◽  
...  
Keyword(s):  
South Africa ◽  
Bone Development ◽  
Bottlenose Dolphins ◽  
Fatal Outcome ◽  
Population Level ◽  
Cape Coast ◽  
Osteolytic Lesions ◽  
Immune Mediated ◽  
Significant Difference ◽  
The Difference

Crassicauda spp. (Nematoda) infest the cranial sinuses of several odontocetes, causing diagnostic trabecular osteolytic lesions. We examined skulls of 77 Indian Ocean humpback dolphins Sousa plumbea and 69 Indo-Pacific bottlenose dolphins Tursiops aduncus, caught in bather-protecting nets off KwaZulu-Natal (KZN) from 1970-2017, and skulls of 6 S. plumbea stranded along the southern Cape coast in South Africa from 1963-2002. Prevalence of cranial crassicaudiasis was evaluated according to sex and cranial maturity. Overall, prevalence in S. plumbea and T. aduncus taken off KZN was 13 and 31.9%, respectively. Parasitosis variably affected 1 or more cranial bones (frontal, pterygoid, maxillary and sphenoid). No significant difference was found by gender for either species, allowing sexes to be pooled. However, there was a significant difference in lesion prevalence by age, with immature T. aduncus 4.6 times more likely affected than adults, while for S. plumbea, the difference was 6.5-fold. As severe osteolytic lesions are unlikely to heal without trace, we propose that infection is more likely to have a fatal outcome for immature dolphins, possibly because of incomplete bone development, lower immune competence in clearing parasites or an over-exuberant inflammatory response in concert with parasitic enzymatic erosion. Cranial osteolysis was not observed in mature males (18 S. plumbea, 21 T. aduncus), suggesting potential cohort-linked immune-mediated resistance to infestation. Crassicauda spp. may play a role in the natural mortality of S. plumbea and T. aduncus, but the pathogenesis and population level impact remain unknown.

Perbedaan Penggunaan Antikoagulan K2EDTA DAN K3EDTA Terhadap Hasil Pemeriksaan Indeks Eritrosit

2018 ◽  
Vol 1 (2) ◽  
pp. 114
Author(s):  
Wahdaniah Wahdaniah ◽  
Sri Tumpuk
Keyword(s):  
Screening Test ◽  
Venous Blood ◽  
The Body ◽  
Ethylene Diamine ◽  
P Value ◽  
Cross Sectional ◽  
Significant Difference ◽  
Ethylene Diamine Tetra Acetate ◽  
The Difference ◽  
Index Value

Abstract: Routine blood examination is the earliest blood test or screening test to determine the diagnosis of an abnormality. Blood easily froze if it is outside the body and can be prevented by the addition of anticoagulants, one of which Ethylene Diamine Tetra Acetate (EDTA). Currently available vacuum tubes containing EDTA anticoagulants in the form of K2EDTA and K3EDTA. K3EDTA is usually a salt that has better stability than other EDTA salts because it shows a pH approaching a blood pH of about 6.4. The purpose of this research is to know the difference of erythrocyte index results include MCH, MCV and MCHC using K3EDTA anticoagulant with K2EDTA. This research is a cross sectional design. This study used venous blood samples mixed with K2EDTA anticoagulant and venous blood mixed with K3EDTA anticoagulants, each of 30 samples. Data were collected and analyzed using paired different test. Based on data analysis that has been done on MCH examination, p value <0,05 then there is a significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value. Then on the examination of MCV and MCHC obtained p value <0.05 then there is no significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value.Abstrak: Pemeriksaan darah rutin merupakan pemeriksaan darah yang paling awal atau screening test untuk mengetahui diagnosis suatu kelainan. Darah mudah membeku jika berada diluar tubuh dan bisa dicegah dengan penambahan antikoagulan, salah satunya Ethylene Diamine Tetra Acetate (EDTA). Dewasa ini telah tersedia tabung vakum yang sudah berisi antikoagulan EDTA dalam bentuk  K2EDTA dan  K3EDTA. K3EDTA  biasanya berupa garam yang mempunyai stabilitas yang lebih baik dari garam EDTA yang lain karena menunjukkan pH yang mendekati pH darah yaitu sekitar 6,4. Tujuan dari penelitian ini adalah untuk mengetahui perbedaan hasil indeks eritrosit meliputi MCH, MCV dan MCHC menggunakan antikoagulan K3EDTA dengan K2EDTA. Penelitian ini merupakan penelitian dengan desain cross sectional. Penelitian ini menggunakan sampel darah vena yang dicampur dengan antikoagulan K2EDTA dan darah vena yang dicampur dengan antikoagulan K3EDTA, masing-masing sebanyak 30 sampel. Data dikumpulkan dan dianalisis menggunakan uji beda berpasangan. Berdasarkan analisis data yang telah dilakukan pada pemeriksaan MCH didapatkan nilai p < 0,05 maka ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit. Kemudian pada pemeriksaan MCV dan MCHC didapatkan nilai p < 0,05 maka tidak ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit.

Pengaruh Jumlah Pencucian Beras dengan Kadar Klorin

2017 ◽  
Vol 1 (1) ◽  
pp. 89
Author(s):  
Indah Purwaningsih ◽  
Supriyanto Supriyanto
Keyword(s):  
Mucous Membrane ◽  
Confidence Level ◽  
Iodometric Titration ◽  
Titration Method ◽  
Anova Test ◽  
Average Value ◽  
Significant Difference ◽  
The Difference

Abstract: Chlorine is a green halogen-shaped halogen gas at normal temperature and serves as bleach, stain remover and disinfectant. Chlorine is now widely used for bleaching rice so that less quality rice looks like quality rice. Chlorine is very toxic and causes mucous membrane irritation, highly reactive and very powerful oxidizer. The purpose of this research was to determine the difference of chlorine level in chlorinated rice washed once, twice and 3 times. The sample in this study amounted to 11 samples calculated by replication formula. Each sample was treated 3 times, ie 1 washed once, 2 washed twice and washed 3 times. The samples then examined by iodometric titration method. Based on the results of the study using ANOVA test, 11 samples obtained the average value of chlorine after washed once amount of 0.0176%, after washed twice amount of 0.0111%, and after washed 3 times amount of 0.0052% with the value significance p = 0.03 (p <0.05) at 95% confidence level which means there was a significant difference between chlorine levels in chlorinated rice washed once, twice and 3 times.Abstrak: Klorin merupakan unsur halogen berbentuk gas berwarna kuning kehijauan pada suhu normal danberfungsi sebagai pemutih, penghilang noda maupun desinfektan. Klorin sekarang banyak digunakan untuk bahan pemutih beras agar beras yang kurang berkualitas tampak seperti beras berkualitas. Klorin sangat toksik dan menyebabkan iritasi membran mukosa, sangat reaktif dan merupakan oksidator yang sangat kuat. Tujuan dari penelitian ini ialah untuk mengetahui perbedaan kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali. Sampel dalam penelitian ini berjumlah 11 sampel yang dihitung dengan rumus replikasi. Setiap sampel diberi perlakuan sebanyak 3 kali, yaitu 1 kali pencucian, 2 kali pencucian dan 3 kali pencucian. Sampel penelitian kemudian diperiksa dengan metode titrasi iodometri. Berdasarkan hasil penelitian menggunakan uji Anova secara komputerisasi terhadap 11 sampel diperoleh nilai rata-rata kadar klorin setelah 1 kali pencucian sebesar 0,0176 %, setelah 2 kali pencucian sebesar 0,0111 %, dan setelah 3 kali pencucian sebesar 0,0052 % dengan nilai signifkansi p = 0,03 (p<0,05) pada tingkat kepercayaan 95% yang artinya ada perbedaan yang bermakna antara kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali.

Nerve graft versus nerve transfer for neonatal brachial plexus: shoulder outcomes

2021 ◽  
Vol 27 (1) ◽  
pp. 87-92
Author(s):  
Brandon W. Smith ◽  
Kate W. C. Chang ◽  
Sravanthi Koduri ◽  
Lynda J. S. Yang
Keyword(s):  
Brachial Plexus ◽  
Clinical Data ◽  
External Rotation ◽  
Nerve Transfer ◽  
Shoulder Function ◽  
Nerve Transfers ◽  
Shoulder Flexion ◽  
Significant Difference ◽  
Transfer Strategies ◽  
Shoulder External Rotation

OBJECTIVEThe decision-making in neonatal brachial plexus palsy (NBPP) treatment continues to have many areas in need of clarification. Graft repair was the gold standard until the introduction of nerve transfer strategies. Currently, there is conflicting evidence regarding outcomes in patients with nerve grafts versus nerve transfers in relation to shoulder function. The objective of this study was to further define the outcomes for reconstruction strategies in NBPP with a specific focus on the shoulder.METHODSA cohort of patients with NBPP and surgical repairs from a single center were reviewed. Demographic and standard clinical data, including imaging and electrodiagnostics, were gathered from a clinical database. Clinical data from physical therapy evaluations, including active and passive range of motion, were examined. Statistical analysis was performed on the available data.RESULTSForty-five patients met the inclusion criteria for this study, 19 with graft repair and 26 with nerve transfers. There were no significant differences in demographics between the two groups. Understandably, there were no patients in the nerve grafting group with preganglionic lesions, resulting in a difference in lesion type between the cohorts. There were no differences in preoperative shoulder function between the cohorts. Both groups reached statistically significant improvements in shoulder flexion and shoulder abduction. The nerve transfer group experienced a significant improvement in shoulder external rotation, from −78° to −28° (p = 0.0001), whereas a significant difference was not reached in the graft group. When compared between groups, there appeared to be a trend favoring nerve transfer in shoulder external rotation, with the graft patients improving by 17° and the transfer patients improving by 49° (p = 0.07).CONCLUSIONSIn NBPP, patients with shoulder weakness experience statistically significant improvements in shoulder flexion and abduction after graft repair or nerve transfer, and patients with nerve transfers additionally experience significant improvement in external rotation. With regard to shoulder external rotation, there appear to be some data supporting the use of nerve transfers.

P-Removal in Completely Mixed Systems

1985 ◽  
Vol 17 (11-12) ◽  
pp. 325-326 ◽  
Author(s):  
H J. G. W. Donker ◽  
P. Opic ◽  
H. P. de Vries
Keyword(s):  
Mixed System ◽  
Domestic Waste ◽  
Recirculation Flow ◽  
Start Up ◽  
Significant Difference ◽  
Aerobic Reactor ◽  
The Difference ◽  
Positive Effect ◽  
Mixed Systems ◽  
P Removal

Ca. 60 % of the Dutch activated sludge plants consist of completely mixed systems, experiments have been carried out in completely mixed pilot plants to study the biological P-removal. The research was carried out in two pilot plants. The pilot plants consisted of: anaerobic reactor, anoxic reactor, aerobic reactor and a clarifier. All the reactors were completely mixed. Both plants were fed with settled domestic waste water at a sludge loading of 400 and 250 g COD/kg sludge.day respectively. The results are given below:sludge loading (g COD/kg sludge.day)400400250ratio Anaerobic : Anoxic : Aerobic1: 1:2,71:1:4,11:1:2,7P-removal (%)802875N-removal (%)505065COD-removal (%)858585 It has been shown that there is no significant difference between the results at the two different sludge loadings. Remarkable is the difference between the ratio 1:1:2,7 in combination with the internal recirculation flow anoxic-anaerobic of 160 % and the ratio 1:1:4,1 with a recirculation flow of 30 %. During the start-up at a sludge loading of 250 g COD/kg sludge.day and an internal recirculation flow of 30 %, bulking sludge developed almost immediately. The Premoval was completely disturbed. Increasing the internal recirculation flow to 160% had a positive effect on settling properties and P-removal. This investigation has pointed out that a completely mixed system is suitable for biological P-removal, without negatively affecting the nitrification. Important factors in the process are the ratio anaerobic:anoxic:aerobic and the recirculation flows.

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