9.2 Flexibility, Core, Balance, Reactive, and Resistance Technique
Key Takeaways
- NASM expects trainers to recognize proper setup and technique across flexibility, core, balance, reactive, and resistance training.
- Technique is judged through the five kinetic-chain checkpoints, posture, control, tempo, breathing, and the client owning the range of motion.
- Resistance training is built from fundamental movement patterns: squat, hip hinge, push (horizontal/vertical), pull (horizontal/vertical), and rotation/carry.
- The major compound lifts (squat, deadlift, bench, overhead press, row) each have a defined setup, execution, and a short list of common faults to watch.
- Reactive and balance drills require landing and alignment quality before height, speed, or instability are added.
Technique Across Integrated Training
NASM uses integrated training, so technique is not limited to barbell lifts. The exam can ask about a foam-roll position, a static stretch, a plank, a single-leg balance drill, a jump landing, a cable row, or a squat. The same coaching question sits underneath each: can the client perform the exercise with the intended muscles and joints controlling the task?
Start with the five kinetic-chain checkpoints. The foot/ankle should be stable for the task. Knees should track in line with the toes. The lumbo-pelvic-hip complex (LPHC) should avoid uncontrolled arching, rounding, or shifting. Shoulders should stay positioned for the movement. The head and cervical spine should avoid jutting, tilting, or excessive tension.
| Modality | Technique priority | Common correction |
|---|---|---|
| Flexibility | Target tissue without compensation or pain | Adjust position, reduce pressure, slow breathing |
| Core | Maintain spinal and pelvic control | Shorten lever, reduce duration, cue draw-in/brace |
| Balance | Keep checkpoint alignment while base of support changes | Return to stable surface or bilateral stance |
| Reactive | Land softly with knees aligned and trunk controlled | Reduce height, speed, or volume |
| Resistance | Move through controlled range under load | Reduce load, range, tempo demand, or complexity |
For flexibility work the target is not to force range. Self-myofascial techniques should be controlled. Static stretching should not create sharp pain or nerve symptoms. Core technique depends on category: a plank is not better because it lasts longer if the low back sags. Balance is tested through progressions — two-leg stable before unstable or single-leg variations; instability is useful only when it challenges control without destroying it. Reactive and plyometric drills magnify errors because force rises quickly; look for quiet, controlled landings with knees tracking over toes.
Resistance Exercise Categories and the Compound Lifts
NASM organizes resistance exercise around fundamental movement patterns rather than isolated body parts: squat, hip hinge, horizontal and vertical push, horizontal and vertical pull, and rotation/carry. A total-body session links these so that the kinetic chain works as a unit, while a body-part focus (chest/push, back/pull, shoulders, legs) selects exercises within one pattern. The major compound lifts each have a defined setup, execution, and fault list the exam expects you to recognize.
| Lift (pattern) | Primary muscles | Setup → execution essentials |
|---|---|---|
| Back/front squat (squat) | Quadriceps, glutes, hamstrings, erector spinae | Feet shoulder-width, brace, knees track over toes, hips and knees flex together to depth, drive through mid-foot |
| Deadlift / RDL (hip hinge) | Glutes, hamstrings, erectors, lats | Bar over mid-foot, neutral spine, hinge at hips with soft knees, bar stays close, extend hips and knees together |
| Bench press (horizontal push) | Pectoralis major, anterior deltoid, triceps | Shoulder blades retracted/depressed, feet planted, slight arch, bar to mid-chest, press up and slightly back |
| Overhead press (vertical push) | Anterior/medial deltoid, triceps, upper traps | Brace core, bar/dumbbell at shoulders, press overhead without ribs flaring, lock out with bar over mid-foot |
| Bent-over / cable row (horizontal pull) | Latissimus dorsi, rhomboids, mid-traps, biceps | Hinge with neutral spine, shoulders down and back, pull elbows behind torso, squeeze shoulder blades |
Common faults and fixes (fault → correction):
| Common fault | Fix |
|---|---|
| Squat: knee valgus (knees cave in) | Cue knees out / track over toes; regress load; foam-roll adductors, activate glutes |
| Squat: heels rising or forward lean | Improve ankle mobility, widen stance, reduce depth or load |
| Deadlift: lumbar rounding | Stop the set, reduce load, reteach hip hinge with neutral spine |
| Bench: elbows flared 90 degrees, shoulders rolled forward | Tuck elbows ~45 degrees, retract/depress scapulae |
| Overhead press: low-back hyperextension (ribs flare) | Brace core, glute squeeze, reduce load or use half-kneeling press |
| Row: shoulder shrugging / upper-back rounding | Cue shoulders down and back, slow tempo, lighter load |
The exam often hides the answer in the word immediate. If a client rounds the low back during a deadlift, the immediate response is to stop the rep or set, reduce load, and reteach the hinge — the longer-term program may add mobility, core, or glute work. Technique is also specific to the person: a client with short legs may need a step under the feet on a bench press; a client with limited shoulder mobility may use a goblet squat instead of a back squat; a client with poor push-up control may use an incline push-up.
These are not easier by default; they are matched to current movement capacity. For study, connect every modality to one question: what is the most conservative change that keeps the training goal and restores control? That is the answer style NASM rewards.
Equipment Selection: Machine, Free Weight, Cable, and Body Weight
The exam also tests how the trainer chooses the tool, because the same pattern can be loaded with a machine, a free weight, a cable, or body weight, and each has trade-offs. Machines fix the movement path and provide built-in stability and safety stops, which makes them useful for beginners, for isolating a muscle, for high-fatigue states, or when a client needs to train safely without a spotter.
Free weights (barbells and dumbbells) demand the client stabilize the load through the full kinetic chain, which carries over well to daily movement and builds stabilization, but raises the skill and spotting requirement. Cables keep constant tension through the range and allow many angles and standing, integrated positions, making them strong choices for stabilization and functional work. Body-weight exercises are scalable through leverage, range, and surface, and require no external load — ideal for early progressions and home settings.
| Tool | Best fit | Trade-off |
|---|---|---|
| Machine | Beginners, isolation, safe high-fatigue work | Less stabilizer demand, fixed path |
| Free weight | Integrated strength, stabilization, carryover | Higher skill and spotting need |
| Cable | Constant tension, many angles, standing work | Setup detail (height/handle) affects line of pull |
| Body weight | Early progressions, home, scalable | Hard to add precise load |
A practical rule: match the tool to the client's stability and skill, the OPT phase, and the safety context. A deconditioned beginner in Phase 1 may use cables and machines plus body-weight stabilization work; a client building maximal strength may need free weights and a competent spotter. The trainer should never let the equipment dictate unsafe technique — if a cable height or machine seat forces a checkpoint out of line, adjust the setup or change tools before adding effort.
A client lands from repeated squat jumps with knees moving inward and loud, stiff foot contact. What is the best modification?
Which muscles are the primary movers in a barbell bench press?
A client rows with the shoulders shrugging up toward the ears. Which cue best reflects correct resistance-training technique?