Open Chain Exercise

Original Editor - Tarina van der Stockt

Top Contributors - Tarina van der Stockt, Aanal Bhuva, Kim Jackson, Evan Thomas, Lucinda hampton, WikiSysop, Naomi O'Reilly, Claire Knott and Wanda van Niekerk

Introduction

The Kinetic Chain is a way of describing human movement and it can either be an open kinetic chain or a closed kinetic chain (CKC).  In an open kinetic chain the segment furthest away from the body( eg foot) is free and not fixed to an object. In a closed kinetic chain the segment furthest away from the body is fixed. Both types of kinetic chain exercises have their advantages. The biggest advantage of an open kinetic chain (OPC) exercise is that it can isolate a muscle.

Use of OKC VS CKC exercises

The use of OCK and CKC exercises often varies often from one practitioner to the next. Numerous studies exist into the effects of these KC exercises. Some of the finding are reported below

• A 2017 study into "The effects of open and closed kinetic chain exercises on the static and dynamic balance of the ankle joints in young healthy women " concluded that the CKC exercises were better at improving balance
• A 2017 systematic review into the effectiveness of OKC VS CKC exercises following ACL reconstruction found no compelling evidence for one over the other
• A 2018 study into shoulder muscle activation patterns in OCK VS CKC exercises found that OCK shoulder abduction is needed to stabilise the head of the rotator cuff (RC) and axioscapular muscles hence CKC exercises are better to use earlier on in rehabilitation programs as they have more built in stability and less demand on RC. A 2017 report however concluded that OKC, CKC and range of movement exercises all seem to be effective in bringing about short term changes in pain and disability in patients with rotator cuff tendinopathy
• a 2017 study titled "The impact of closed versus open kinetic chain exercises on osteoporotic femur neck and risk of fall in postmenopausal women." concluded that CKC exercises were the best to choose to diminish the effects of the disease and reduce the risk of falls.

Characteristic	Open kinetic chain exercises	Example: seated knee extension
Stress pattern	Rotary	The primary stress to the joint is rotation of the proximal tibia on the distal femur
Number of joint axes	One primary	Knee extension primarily occur in the sagittal plane
Nature of joint segments	One stationary, other mobile
Number of moving joints	Isolated joint motion	The femur remains stationary while the tibia is moving
Planes of movement	One (single)
Muscular involvement	Isolation of muscle group activation	Minimal muscle co-contraction is used to do the movement
Movement pattern	Often non-functional

Biomechanical and Neurophysiological Factors

OKC exercises allow for motion in the distal segment while movement is restricted to a single joint. This typically includes exercises to improve strength and range of motion. 

Characteristics of typical non-weight bearing activities:

• Increased distraction and rotational forces
• Increased acceleration forces
• Decreased resistance forces
• Increased deformation of joint and muscle mechanoreceptors
• Increased concentric acceleration and eccentric deceleration forces
• Promotion of functional activities
• Requires agonist-antagonist force couples

Open Chain Upper-Body Kinetic Exercises

• Bench press
• Biceps curl
• Chest-fly
• Lat pull down
• Tricep extensions
  

Bench Press

Bicep Curl

Chest-fly

Lat pull down

Tricep extension

Open Chain Lower-Body Kinetic Exercises

• Seated leg extension
• Terminal knee extension exercises
• Hamstring curl
• Plantar / dorsiflexion (calf pumps)

Leg extension

Terminal knee extension

Hamstring curl

Plantarflexion/dorsiflexion

Clinical Bottom Line

Many factors should be considered when deciding to use open kinetic chain exercises versus closed kinetic chain exercises. The patient's condition and stage of rehabilitation will aid in the clinician's judgement of exercise prescription.