Closed-kinetic chain exercise

A closed-kinetic chain exercise is one in which the distal segment of the

extremity is fixed or stabilized. In an open-kinetic chain, the distal segment is mobile and is not fixed. Closed-kinetic chain exercises in the lower extremity decrease the

shear forces, reducing anterior tibial translation, and increase the compressive forces, which increases stability around the knee joint. Biomechanically, closed-kinetic chain exercises function to decrease the knee flexion moment and increase the hip flexion moment. Closed-kinetic chain exercises induce co-contraction of the hamstrings, which helps to decrease the shear forces at the knee joint. The majority of functional activities involve a closed-kinetic chain system. Closed-kinetic chain exercises have become the recommended strengthening technique of injuries involving in particular the ACL (anterior cruciate ligament). Mini-squats, leg press, stepping exercise, lateral step-up, terminal knee extension using rubber tubing, and stationary bicycling are all examples of closed- kinetic chain activities for the lower extremity. Closed-kinetic chain activities, such as push-ups and weight-shifting, are strengthening exercises used primarily for improving shoulder stabilization in the upper extremity.

Closed-kinetic chain exercises induce hamstring contraction by creating a flexion moment at both A, hip; B, knee; and C, ankle.

6.1. Read the text “Closed-Kinetic Chain Exercise” and translate it in writing.

6.2. Ask 15 questions of all types to the text.

6.3. Find English equivalents in the text for the following.

упражнение с кинетически замкнутым циклом, периферический сегмент, конечность, фиксированный, устойчивый, кинетически открытая цепь, подвиж-ный, уменьшать, поперечная сила/сдвигающее усилие, сокращать, перенос/ перемещение, передняя, большая берцовая, сжимающая сила / сжимающее усилие, коленный сустав, момент сгибания колена, увеличивать, момент сгибания бедра, вызывать/стимулировать, сокращение, подколенное сухожилие, большинство, вовлекать, в особенности, передняя крестообразная связка колена, полуприсядь, жим ногами, упражнения на степ-тренажерах, упражнения на латеральных степ-тренажерах, полное распрямление колена, резиновый шланг, вело-тренажер, отжимания, перемещение тяжестей, силовые упражнения, в основном/главным образом, устойчивость, плечо, верхняя конечность

6.4. Complete the sentences with logical endings.

1. A closed-kinetic chain exercise is one in which the distal segment of the extremity.... 2. In an open-kinetic chain, the distal segment is …. 3. Closed-kinetic chain exercises in the lower extremity decrease..., reducing anterior tibial translation, and increase.... 4. Biomechanically, closed-kinetic chain exercises function to decrease... and increase the.... 5. Closed-kinetic chain exercises induce.... 6. Closed-kinetic chain exercises have become the recommended strengthening technique of injuries involving....

Standard leg press exercise

6.5. Find the predicate in the following sentences and define the tense and

voice form of the verb in it.

1. In closed-kinetic chain exercise, the flexion moment increases as the knee flexes, once again causing increased quadriceps and patellar tendon tension thus an increase in patellofemoral joint reaction forces. 2. However, the patella has a much larger surface contact area with the femur, and contact stress is minimized. 3. Closed-kinetic chain exercises may be better tolerated in the patellofemoral joints since contact stress is minimized.

Modified and recommended leg press positioning

6.6. Complete the sentences with the words from a box.

the distal segment, extremity, closed-kinetic chain exercise, stabilized or fixed, kinetic, machine

1. In recent years the concept of …-… … … has received considerable attention as a useful and effective technique of rehabilitation, particularly for injuries involving the lower extremity. 2. The ankle, knee, and hip joints comprise the kinetic chain for the lower …. 3. When the distal segment of the lower extremity is … or …, as is the case when the foot is weightbearing on the ground, the … chain is said to be closed. 4. Conversely, in anopen kinetic chain, … … … is mobile and is not fixed. 5. Traditionally, rehabilitation strengthening protocols have used open-kinetic chain exercises such as knee flexion and extension on a knee ….

Stairmaster stepping machine

6.7. Put questions to the words in italics.

1. Closed-kinetic chain exercises have two distinct advantages over open-kinetic chain exercises. 2. From a biomechanica l perspective, they are safer and produce stresses and forces that are potentially less of a threat to healing structures. 3. They are also more functional than open-kinetic chain exercises since they involve weight-bearing activities. 4. While closed-kinetic chain exercises are more often used in lower extremity rehabilitation, they may also be useful in rehabilitation protocols for certain upper extremity activities as well.

6.8. Insert articles if necessary. CONCEPT OF THE KINETIC CHAIN   The concept of … kinetic chain was first proposed in … 1970s and was initially referred to as … link system by mechanical engineers. 2. In this link system, pin joints connect … series of overlapping, rigid segments. 3. If both ends of this system are connected to an immovable frame, translation of … proximal or distal ends is impossible. 4. In this closed link system, movement at one joint produces … predictable movement at all other joints. 5. This type of closed link system does not exist in either … upper or lower extremities. 6. However, when … distal segment in the extremity (that is, … foot or hand) meets resistance, muscle recruitment patterns and joint movements are different than when … distal segment moves freely. 7. Thus two systems, … open and … closed system, were proposed. 8. Whenever …

Mathematical model showing shear and compressive force vectors. S = shear, C = compressive.

foot or … hand meets resistance, … closed kinetic chain exists. 9. … true closed kinetic chain can only exist during isometric exercise, since neither … proximal nor distal segments can move in … closed system.

6.9. Fill in the gaps with the prepositions if necessary.