1A2-K08 Development of a 7 DOF Hip Joint Motion Simulator

The many muscles crossing the elbow joint allow for its motions to be created from different combinations of muscular activations. Muscles are strictly contractile elements and the joints they surround rely on varying loads from opposing antagonists for stability and movement. In designing a control system to actuate an elbow in a realistic manner, unidirectional, tendon-like actuation and muscle co-activation must be considered in order to successfully control the elbow’s two degrees of freedom. Also important is the multifunctionality of certain muscles, such as the biceps brachii, which create moments impacting both degrees of freedom: flexion / extension and pronation / supination. This paper seeks to develop and implement control algorithms on an elbow joint motion simulator that actuates cadaveric elbow specimens via four major muscles that cross the elbow joint. The algorithms were validated using an anatomically-realistic mechanical elbow. Clinically-meaningful results, such as the evaluation of radial head implants, can only be obtained under repeatable, realistic conditions; therefore, physiologic motions must be created by the application of appropriate loads. This is achieved by including load control on the muscles’ actuators as well as displacement control on both flexion / extension and supination / pronation.

Download Full-text

Conservative treatment in children with Legg-Calve-Perthes disease, aged up to 7 years

Chirurgia Narządów Ruchu i Ortopedia Polska ◽

10.31139/chnriop.2020.85.5-6.1 ◽

2020 ◽

Vol 85 (5-6) ◽

pp. 91-96

Author(s):

Marek A Synder ◽

◽

Marek Maricniak ◽

Marek Drobniewski ◽

Marek Synder ◽

...

Keyword(s):

Quality Of Life ◽

Conservative Treatment ◽

Hip Joint ◽

Complete Healing ◽

Perthes Disease ◽

Joint Motion ◽

Healthy Children ◽

Joint Development ◽

Healthy Side

Introduction. Legg-Calve-Perthes disease is one of the most common avascular necroses in children and adolescents. Aims. Assessment of hip joint development and of the quality of life in conservatively treated patients. Establishing indications for conservative treatment in children with Perthes disease. Materials and methods. The inclusion criterion was the age of affected patients: under 7 years at the time of diagnosis The study population included 50 children (10 girls and 40 boys) in the mean age of 5 years and 1 month. All the children participated in follow up appointments, arranged every 3 months, during which clinical examinations (the range of hip joint motion, limb length) were carried out and radiological parameters (Salter extrusion index, ATD, Wiberg angle) were assessed. All the patients were assessed in the IPSG Modified HOOS-16 Hip Survey. Results. The patients, qualified to group A by the Herring classification, demonstrated less limits in hip joint inward rotation and no length reduction of the affected limb (p<0.05). In the patients with Wiberg angle and Salter extrusion index in the affected joint being similar to their corresponding values on the healthy side, the intensity of pain was lower, assessed in the IPSG Modified HOOS-16 Hip Survey, as well as their functioning in everyday life and in sport and recreation activities was better, thus their general quality of life was higher (p <0.05). Conclusions. Children with Perthes disease, diagnosed before the age of 7, do not usually require surgical intervention. In our study, the radiological evaluation of hip joint development showed complete healing of the proximal femoral epiphysis, while preserving femoral head sphericity and good hip functionality. In general, the quality of life of affected patients does not differ from the quality of life of healthy children. The indication for conservative treatment of children with Perthes disease is their age below 7 years. Then a regular monitoring of the course of physiotherapeutic therapy is required, combined with regular radiological controls and clinical assessments of hip joint motion range.

Download Full-text

The Large Individual Differences in the Range of Hip Joint Motion Rather Than Lumbar Spine Motion Affect Dynamic Spinopelvic Rhythm

Spine Surgery and Related Research ◽

10.22603/ssrr.2018-0089 ◽

2019 ◽

Vol 3 (3) ◽

pp. 255-260

Author(s):

Katsuhito Yoshioka ◽

Hideki Murakami ◽

Satoru Demura ◽

Satoshi Kato ◽

Hiroki Kawashima ◽

...

Keyword(s):

Individual Differences ◽

Lumbar Spine ◽

Hip Joint ◽

Large Individual ◽

Joint Motion ◽

Spine Motion

Download Full-text

Using Magneto-Inertial Measurement Units to Pervasively Measure Hip Joint Motion during Sports

Sensors ◽

10.3390/s20174970 ◽

2020 ◽

Vol 20 (17) ◽

pp. 4970

Author(s):

Rachel E. Horenstein ◽

Yohann R. Goudeau ◽

Cara L. Lewis ◽

Sandra J. Shefelbine

Keyword(s):

Hip Joint ◽

Wireless Sensors ◽

Measurement Unit ◽

After School ◽

Joint Motion ◽

Inertial Measurement ◽

School Activities ◽

Elite Level ◽

Joint Motions ◽

Future Work

The use of wireless sensors to measure motion in non-laboratory settings continues to grow in popularity. Thus far, most validated systems have been applied to measurements in controlled settings and/or for prescribed motions. The aim of this study was to characterize adolescent hip joint motion of elite-level athletes (soccer players) during practice and recreationally active peers (controls) in after-school activities using a magneto-inertial measurement unit (MIMU) system. Opal wireless sensors (APDM Inc., Portland OR, USA) were placed at the sacrum and laterally on each thigh (three sensors total). Hip joint motion was characterized by hip acceleration and hip orientation for one hour of activity on a sports field. Our methods and analysis techniques can be applied to other joints and activities. We also provide recommendations in order to guide future work using MIMUs to pervasively assess joint motions of clinical relevance.

Download Full-text