FF - MSK Basics: Biomechanics and Kinematic Chain

What is an open kinetic chain (OKC)?

Distal segment is free to move (e.g., seated knee extension)

What is a closed kinetic chain (CKC)?

Distal segment is fixed (e.g., squat, push-up)

Which kinetic chain is more functional for weight-bearing activities?

Closed kinetic chain (CKC)

Hypomobility at one joint often causes what at another joint?

Hypermobility

What are the three arthrokinematic motions?

Roll, glide (slide), and spin

What happens when a convex surface moves on a fixed concave surface?

Roll and glide occur in opposite directions

What happens when a concave surface moves on a fixed convex surface?

Roll and glide occur in the same direction

What NPTE phrase should you remember for convex-on-concave movement?

Roll and glide are opposite

A patient is evaluated three months after a right ankle fracture. Active range of motion measures 0°-10° of plantarflexion and 0°-20° of dorsiflexion. Which joint mobilization technique is MOST APPROPRIATE to improve plantarflexion?

Anterior glide of talus on tibia

To improve plantarflexion, mobilize the talus which direction?

Posterior glide

To improve dorsiflexion, mobilize the talus which direction?

Anterior glide

During shoulder internal rotation, which direction does the humeral head glide?

Posterior glide.

During shoulder external rotation, which direction does the humeral head glide?

Anterior glide

Shoulder extension requires what humeral glide?

Anterior glide

At the TMJ, which surface is convex?

Mandibular head/condyle

At the TMJ, which surface is concave?

Mandibular fossa of the temporal bone

During TMJ elevation/closing, what are the arthrokinematics?

Anterior roll + posterior slide

What glide increases TMJ elevation/closing?

Posterior glide

During early TMJ depression/opening, what occurs?

Posterior roll + anterior slide

During the late phase of TMJ depression, what happens?

The condyle and disc slide together forward and inferiorly

What glide increases TMJ depression/opening?

Anterior glide

During TMJ protrusion, what happens?

The mandibular condyle and disc translate anteriorly

During TMJ retrusion, what happens?

The mandibular condyle and disc translate posteriorly

During left lateral excursion of the mandible, what happens to the left condyle?

The left condyle forms a pivot point

At the sternoclavicular joint during elevation/depression, what surfaces articulate?

Convex clavicle on concave sternum

At the sternoclavicular joint during protraction/retraction, what surfaces articulate?

Convex sternum on concave clavicle

What are the arthrokinematics of SC joint elevation?

Superior roll + inferior slide → inferior glide (to mobilize)

What are the arthrokinematics of SC joint depression?

Inferior roll + superior slide → superior glide

What are the arthrokinematics of SC joint protraction?

Anterior roll + anterior slide → anterior glide

What are the arthrokinematics of SC joint retraction?

Posterior roll + posterior slide → posterior glide

At the GH joint, which surface is convex? Which is concave?

Humeral head convex

Glenoid fossa concave

What moves on what at the GH joint?

Humerus on glenoid fossa

GH flexion: roll and slide?

Anterior roll + posterior slide

What glide increases GH flexion?

Posterior

GH extension: roll and slide?

Posterior roll + anterior slide

What glide increases GH extension?

Anterior

GH abduction: roll and slide?

Superior roll + inferior slide

What glide increases GH abduction?

Inferior glide

GH adduction: roll and slide?

Inferior roll + superior slide

What glide increases GH adduction?

Superior glide

GH internal rotation: roll and slide?

Anterior roll + posterior slide

What glide increases GH internal rotation?

Posterior

GH external rotation: roll and slide?

Posterior roll + anterior slide

What glide increases GH external rotation?

Anterior

GH horizontal abduction: roll and slide?

Posterior roll + anterior slide → anterior glide

GH horizontal adduction: roll and slide?

Anterior roll + posterior slide → posterior glide

At the radiohumeral joint, which surface is convex and which is concave?

Capitulum; Radial head

What moves on what at the radiohumeral joint?

Radius on humerus

Radiohumeral flexion: roll and slide?

Anterior roll + anterior slide → anterior glide

Radiohumeral extension: roll and slide?

Posterior roll + posterior slide → posterior glide

At the proximal radioulnar joint, which surface is convex?

Radius

At the proximal radioulnar joint, which surface is concave?

Ulna

What moves on what at the proximal radioulnar joint?

Radius on ulna

Proximal radioulnar pronation: roll and slide?

Anterior roll + posterior slide → posterior glide

Proximal radioulnar supination: roll and slide?

Posterior roll + anterior slide → anterior glide

At the distal radioulnar joint, which surface is convex? At the distal radioulnar joint, which surface is concave?

Ulna; Radius

What moves on what at the distal radioulnar joint?

Radius on ulna

Distal radioulnar pronation: roll and slide?

Anterior roll + anterior slide → anterior glide

Distal radioulnar supination: roll and slide?

Posterior roll + posterior slide → posterior glide

At the radiocarpal joint, which surface is convex?

Proximal carpal row

Which surface is concave at the radiocarpal joint?

Radius

What moves on what at the wrist?

Carpals on radius

Wrist flexion: roll and slide?

Anterior roll + posterior slide → posterior glide (to mobilize)

Wrist extension: roll and slide?

Posterior roll + anterior slide → anterior glide

Wrist ulnar deviation: roll and slide?

Ulnar/medial roll + radial/lateral slide → radial/lateral glide

Wrist radial deviation: roll and slide?

Radial/lateral roll + ulnar/medial slide → ulnar/medial glide

At the MCP joint, which surface is convex?

Metacarpal head

Which surface is concave at the MCP joint?

Proximal phalanx

What moves on what at the MCP joint?

Proximal phalanx on metacarpal

MCP flexion: roll and slide?

Anterior roll + anterior slide → anterior glide

MCP extension: roll and slide?

Posterior roll + posterior slide → posterior glide

MCP abduction: roll and slide?

Lateral roll + lateral slide → lateral glide

MCP adduction: roll and slide?

Medial roll + medial slide → medial glide

What type of joint is the thumb CMC joint?

Saddle joint

During thumb CMC abduction/adduction, which surface is concave and which is convex?

Trapezium = concave; proximal metacarpal = convex

During thumb CMC flexion/extension, which surface is convex and which is concave?

Trapezium = convex; proximal metacarpal = concave.

Thumb CMC flexion: roll and slide?

Ulnar roll + ulnar slide → ulnar glide

Thumb CMC extension: roll and slide?

Radial roll + radial slide → radial glide

Thumb CMC abduction: roll and slide?

Volar roll + dorsal slide → dorsal glide

Thumb CMC adduction: roll and slide?

Dorsal roll + volar slide → volar glide

At the hip, which surface is convex? Which is concave?

Femoral head; Acetabulum

What moves on what at the hip?

Femoral head on acetabular fossa

Hip flexion: roll and slide?

Anterior roll + posterior slide

What mob glide to do to inc motion at the hip for hip flexion?

Posterior glide

Hip extension: roll and slide?

Posterior roll + anterior slide

What mob glide to do to inc motion at the hip for extension?

Anterior

Hip abduction: roll and slide?

Lateral/superior roll + inferior slide

What mob glide to do to inc motion at the hip for abduction?

Inferior glide

Hip adduction: roll and slide?

Medial/inferior roll + superior slide

What mob glide to do to inc motion at the hip for adduction?

Superior glide

Hip internal rotation: roll and slide?

Anterior roll + posterior slide

What mob glide to do to inc motion at the hip for IR?

Posterior

Hip external rotation: roll and slide?

Posterior roll + anterior slide → anterior glide

What mob glide to do to inc motion at the hip for ER?

Anterior

At the tibiofemoral joint, which surface is convex? Which is concave?

Femur; Tibia

In OKC knee flexion (tibia on femur), what are the arthrokinematics?

Posterior roll + posterior slide → posterior glide

In OKC knee extension (tibia on femur), what are the arthrokinematics?

Anterior roll + anterior slide → anterior glide

In CKC knee flexion (femur on tibia), what are the arthrokinematics?

Posterior roll + anterior slide → anterior glide

In CKC knee extension (femur on tibia), what are the arthrokinematics?

Anterior roll + posterior slide → posterior glide

During knee flexion, which direction does the patella slide?

Inferior