The Effects of a Supportive Knee Brace on Leg Performance in Healthy Subjects

Abstract

Eight healthy volunteers were fitted with a supportive knee brace (Push Brace 'Heavy') to one knee for a duration of four weeks wherein they were tested before, during and after the application to establish the effect of bracing on performance. The tests consisted of isokinetic strength measurement of knee flexion and extension, 60 meter dash, vertical jump height and a progressive horizontal treadmill test until exhaustion (Vmax) with determination of oxygen uptake, heart rate and plasma lactate concentration. Wearing the brace for one day, the performance indicators showed a decline compared with the test before application (base values). Sprint time was 4% longer (p less than 0.01) and Vmax 6% slower (p less than 0.01). Peak torque of knee flexion at 60 and 240 deg.sec-1 was 6% (p less than 0.05) respectively 9% (p less than 0.05) less. Peak extension torque at 60 deg.sec-1 was 9% less (p less than 0.05). While wearing the brace for four weeks, the test performances were practically identical to their base values. After removal of the brace, all test parameters were statistically similar to the base values. Heart rate at submaximal exercise levels was even lower (p less than 0.05). In conclusion, performance in sports with test-like exercise patterns is not affected by the brace tested. Bracing does not "weaken the knee" as it is widely believed in sports practice.

Do Knee Braces Prevent Ski Knee Injuries?

“…Athlete adjustment to the brace seems to be possible in terms of reaction, fatigue, and performance (23,24). After 14 hours of brace use, no differences in braced and non-braced groups were found, suggesting the need for an adaptation phase before engaging in full sport activity (24,25).…”

Quadriceps Function After Exercise in Patients with Anterior Cruciate Ligament–Reconstructed Knees Wearing Knee Braces

“…Our findings are consistent with those of previous researchers [15][16][17] who demonstrated a decrease in quadriceps muscle function and activation after aerobic exercise. Although numerous authors have looked at the effects of knee braces [18][19][20][21][22][23][24][25][26][27][28][29] and neoprene sleeves 10,30 on neuromuscular performance during dynamic activities, very few have compared these effects during a bout of aerobic exercise. Previous studies of knee bracing and neuromuscular function have indicated that knee braces 21,22,24,[26][27][28] decreased quadriceps muscle function and that neoprene sleeves 10,30 improved knee joint proprioception.…”

“…21,24,26,27 The added bulk and weight of braces may also be concerning to athletes. 27,28 Therefore, whether a person with an ACLR should wear a brace must be determined in light of the potential advantages and disadvantages. However, according to our results, wearing a brace or knee sleeve during aerobic exercise did not influence the change in torque production or central drive to the quadriceps in people with ACLRs.…”

Die Anwendung äußerer Kniegelenkstabilisatoren - Einflussnahme auf mechanische Stabilisierung und körperliche Leistungsfähigkeit

“…Die Aussagen über die akute Beeinflussung der körperlichen Leistungsfähigkeit bei Orthesenapplikation wird von der Literatur noch uneinheitlich beurteilt [2,17]. Dagegen konnte als positives Langzeitergebnis im Rahmen von mehrwöchigen rehabilitativen Maûnahmen nach Entfernung der Orthese mehrheitlich nachgewiesen werden, dass es zu keiner Veränderung der körperlichen Leistungsfähigkeit im Vergleich zum Ausgangswert gekommen ist [18]. Dieses Ergebnis ist ein Beleg dafür, dass entscheidende biomechanische Parameter wie z.…”